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An evolutionary outlook on motivation: Implications for the clinical dialogue∗*

Mauricio Cortina**, Giovanni Liotti***

Abstract. An evolutionary perspective on motivation: Implications for clinical dialogue. A taxonomy of basic motivational systems (reptilian, mammalian and neo-mammalian), that emerged in phases during the course of millions of years, is proposed. These different phases did not replace each other, but became re-organized in the brain at different hierarchical levels. It is argued that (1) humans are an ultracooperative species, and (2) high degrees of cooperation put strong selective pressures toward the development of sophisticated forms of intersubjective communication. These two developments had cascading effects on human evolution, creating the conditions upon which humans were able to understand intentions, gestures, emotions and ultimately the minds of others, and the emergence of language and symbolic forms cultural evolution. Possible evolutionary steps that led to this ultracooperative survival strategy and some of their genetic mechanism, with special emphasis on a multilevel model of selection, are described, and the implications for psychotherapy and psychoanalysis are explored. [KEY WORDS: motivation, cooperation, intersubjective communication, multilevel selection, psychotherapy]

Summary

Social instincts (motivational systems) among primates can be grouped into five major categories:

systems that regulate ritualized dominance and submission displays (dominance hierarchies), systems that regulate care-seeking (attachment) and care-giving behaviors, systems that regulate cooperative behaviors toward members of a troupe, and systems that regulate sexual behaviors. Non-social instincts are, of course, also part of our evolutionary heritage. These ancient “reptilian” systems evolved to maintain physiologic equilibrium, regulate fight-flight-freeze responses, activate predatory behaviors, explore the environment, protect territorial boundaries, and reproduce sexually.

While different forms of cooperation exist among primates, dominance hierarchies based on competition are the main form of social organization in nonhuman primates and cooperation is limited to dyadic interactions or small-scale levels of cooperation such as helping members with close genetic ties or defending territorial boundaries. Helping nonkin members of a group is rare. By comparison, altruistic cooperation in humans is directed at kin and nonkin members alike, and is widespread. Explaining how prosocial form of cooperation evolved among our human (hominin) ancestors has been one of the great scientific challenges of our times. We address this question in two parts.

First, we describe four interrelated evolutionary strategies that emerged among our hominin ancestors that converged in our species to create ultracooperative adaptive strategies: cooperation in helping raise the young (cooperative breeding), the emergence of enduring sexual bonds, the emergence of shared prosocial norms that supported en egalitarian ethos among nomadic hunter gatherers, and an very delayed sexual maturation and prolonged adolescence (life history strategies) that support cultural learning and the remarkable adaptive flexibility of our species.

∗ Accepted for publication in Psychoanalytic Inquiry on a special issue dedicated to evolutionary approaches to psyhoanalysis. Do not cite until essay is published.

** Direcor, Attachment and Huma Development Center Washington D.C, USA, E-Mail <mcortina1945@gmail.com>. *** Associazione per la Ricerca sulla Psicopatologia dell'Attaccamento e dello Sviluppo (ARPAS), Piazza Tuscolo 5,

00183 Roma, Tel. 06-77206593, Tel./Fax 06-70496660, E-Mail <gio.liotti@fastwebnet.it>.

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Second, we turn to formal genetic explanations of the evolution of altruism and cooperation. The classic explanation for the origin of altruism and cooperation is based on genetic relatedness (kin selection), but models confined to altruism among close family members cannot explain some of the characteristic forms of human cooperation and helping. For this extensive form of altruism and cooperative to emerge among ancestral bands of nomadic hunter-gatherers, selection pressures would have had to operate at the level of individuals and of groups (a multilevel view of selection). Groups with more prosocial cooperators prevail over less cooperative groups. A cultural form of multilevel selection emerged in our species based on shared social norms that support fairness and equality, and sanctions that kept alpha individuals and free riders from taking over the group.

High degrees of cooperation put strong selective pressures toward the development of sophisticated forms of intersubjective communication. The co-evolution of egalitarian forms of cooperation and advanced intersubjetive abilities created the conditions upon which humans were able to “sense” into the minds of others (empathy). The end result of this neo-mammalian evolutionary pathway was the emergence of language and a symbolic form of evolution based on learning (cultural evolution). Cultural learning is transmitted from one generation to the next, is therefore cumulative (is heritable) and produces cultural differences. Diversity and heritability will automatically create selection pressures, whether heritability is based on genes or on the transmission of learned cultural traits.

Motivational systems – reptilian, mammalian and neo-mammalian – emerged in phases during the course of millions of years. These different phases did not replace each other, but became re-organized in the brain at different hierarchical levels, as can be seen and inferred by its architecture. This evolutionary model of the human brain was put forward by Hughlings Jackson in early 20th century and by Paul MacLean in the 1980’s. We explore some of the implications of this hierarchical, multi-motivational, cooperative-communication model of the mind for psychotherapy and psychoanalysis.

Introduction

Charles Darwin’s third book – The Expression of the Emotions in Man and Animals (1872) – was the first attempt to look at emotions, emotional communications and their underlying motives from an evolutionary perspective based on his theory of natural selection. His approach was nothing short of revolutionary, opening a new field of study. Unfortunately his approach did not bear much fruit until 150 years later, as can be seen by an explosion of articles and books that have appeared in the last few decades on evolutionary anthropology and psychology. Just for purposes of illustration, within the last few years there have been more than a dozen major books published that address the main themes that inform this essay. Namely the evolutionary origin of advanced forms of cooperation, altruism and cultural evolution (Boehm, 2012; Boehm, 1999; Bowles & Gintis, 2011; Boyd & Richerson, 2005; de Waal, 2009; Henrich & Henrich, 2007; Nowak & Highfield, 2011; Sober & Wilson, 1998; Tomasello, 1999, 2009; Wilson, 2012) and on the relationship between advanced forms of cooperation, social understanding and human communication (Fernandez-Doque & Baird, 2005; Hrdy, 2009; Tomasello, 2008).

The birth of psychoanalysis was heavily influenced by evolutionary ideas. Unfortunately, Freud reverted to a pre-Darwinian notion that adaptations acquired during the course of development (phenotypes) could be directly inherited and passed on to future generations (genotype). Freud coupled this Lamarckian idea with Haeckel’s famous biogenetic law, “ontogeny repeated phylogeny”, and used these two concepts to support many of his core ideas (Sulloway, 1979). For example, in Totem and Taboo Freud (1913) argued that during the prehistory of our species a band of brothers rebelled against a despotic father that had control of all the females, by killing and devouring him, and unleashing incestuous impulses. This alleged episode in the prehistory of our species became ritualized, according to Freud, in the form of a totemic meal. Guilt against incestuous and murderous impulses became

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regulated by rules of exogamy and incest taboos. The memory of this patricidal impulse was inherited and passed on to the next generations (Lamarckism) and then recapitulated (ontogeny recapitulates phylogeny) during development in the form of an Oedipal complex.

As outlandish as Freud’s ideas may seem, they contain a kernel of truth. One of the key questions in human evolution is how a social system based primarily on dominance hierarchies that are observed in all primates, was partially suppressed in favor of egalitarian forms of cooperation as observed among contemporary nomadic hunter-gatherers. We will present evidence supporting cultural continuity between contemporary nomadic foragers and ancestral foragers that began to exhibit evidence of behavioral and cultural modernity during the late Pleistocene, 126,000 to 12,000 years Before Present (BP). Freud was on to something important when he postulated the idea that civilization (Freud used the German word kultur) came about by the repression of antisocial impulses. Nomadic foragers had to “suppress” dominant alphas and free riders in order to achieve high levels of collaboration and mutuality, one of the central hallmarks of our species (Bowles & Gintis, 2011; Henrich & Henrich, 2006; Tomasello, 1999, 2009). As we will explain later, it is likely that the main motivation toward helping others (who are not genetically related) began with cooperative breeding (see below) and was driven by the need to coordinate group hunting and scavenging expeditions and insure meat would be shared equally among members of nomadic bands after hunting large game (Boehm, 2012; Boehm, 1999).

Within psychoanalysis, Darwin’s natural selection approach finally bore fruit when John Bowlby put attachment theory within a modern evolutionary framework (Bowlby, 1969, 1973, 1980). Slavin & Kriegman (1992) published another important book using modern evolutionary theory based on the work of the distinguished evolutionary thinker Robert Trivers that focused on parent-offspring conflict (1974) and the evolution of altruism through mutual and conditional forms of reciprocity (Trivers, 1971). As we will note later, while conditional forms of reciprocity such as “Tit for Tat” strategies (Axelrod & Hamilton, 1981) may have played a role in the evolution of altruism and cooperation, what is characteristic of the human form of cooperation and altruism is that it can be unconditional and does not depend on a direct “Tit for Tat” form of reciprocity (Bowles & Gintis, 2011; Henrich & Henrich, 2006). Humans will spontaneously help strangers in distress or take care of the sick and the disabled without any expectation of reciprocity, behaviors that can already be seen in 18 month-old toddlers (Tomasello, 2007). No other species displays this amount of helpfulness toward conspecifics (other members of their species) with which they do not have a close genetic relationship (Bowles & Gintis, 2011; Boyd, 2006; Clutton-Brock, 2009). Langs’ theory of emotion processing was yet another attempt within psychoanalysis to adopt a modern evolutionary framework (1996). Cortina and Liotti (2010) have introduced an evolutionary approach that focuses on the relationships between attachment, cooperation, intersubjective sharing and social understanding.

Joe Lichtenberg pioneered a multimotivational model that replaced Freud’s outdated drive theory (1989; Lichtenberg, Lachmann, & Fosshage, 2011). While he and his colleagues derived their model by drawing primarily from infant observation and research, there is a close resemblance to the model we are putting forward in this essay. In their latest look at motivational systems (2011), Lichtenberg and his colleagues come up with seven basic systems. The regulation of physiologic needs, attachment, caregiving, sexuality, exploration/competence, an aversive defensive system, and an affiliative system that they think is connected to groups. As far as we know, the only other multimotivational model in psychoanalysis has been put forward by the Spanish psychoanalyst Hugo Bleichmar (1997). Except for a book chapter (Bleichmar, 2003), his work unfortunately has not been translated from Spanish. Within the attachment literature, Jude Cassidy has also put forward a multimotivational model that closely resembles our own except that she calls them behavioral systems: attachment, caregiving, fear, sociable, and exploratory systems (Cassidy, 2008). Within the organizational psychology literature the psychoanalyst and anthropologist Michael Maccoby (1988) has also provided a multimotivational

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model. Despite important differences, there is a substantial overlap among these different multimotivational models.

One of the most prominent applications of a Darwinian approach to motivation and emotions outside the purview of psychoanalysis has been the work of the distinguished neuroscientist Jaak Panksepp (1998; 2012). There has been some cross-talk between Panksepp’s neuroevolutionary approach and psychoanalysis (Solms & Panksepp, 2012). In his latest book Panksepp describes six systems (2012). A seeking system that explores the environment and seeks novelty, a fear system, a rage system, a lustful/sexual system, a caregiving/nurturing system and a system that reacts with panic or grief when caregiving is unavailable or is lost.

Definition of terms

Following Lichtenberg (2005) we will use the language of motivational systems, rather than the traditional concept of instinct or drive. The classical concept of instinct or drive seldom makes reference to the specific goals and emotional cues that activate and temporarily “deactivate” instinctual behaviors (there is a constant shift in motivational system from being in the foreground to being in the background). Some of these emotional cues are felt and some are not. All these components of instinctual behaviors function as a system that is closely regulated and monitored, not unlike other physiologic systems in the body. The traditional concept of instinct also does not always emphasize the enormous importance of the role of experience, which allows the organism to respond flexibly to different environments. This experience is carried forward during development as a series of mostly unconscious expectations coded at implicit levels (Cortina & Liotti, 2007; Fosshage, 2005; Renn, 2012).. Nonetheless, we will occasionally use the old language of instinct to denote the biological roots of social motivations, with the understanding that we do not mean by instinct fixed action patterns relatively immune to environmental influences.

The word altruism will be used for helping behaviors insofar as they incur a direct cost in fitness to the donor. In other words, the donor would be better of, or would have increased his fitness, if he or she withheld from the altruistic act. We will use the word prosocial to helping behaviors regardless of whether they involve a sacrifice from the donor.

In the evolutionary literature a distinction is made between distal (phylogenetic) and proximal (ontogenetic) levels of analysis. It is important to keep this distinction in mind in regard to the evolution of altruism and cooperation, since a great deal of confusion is generated when these two levels of analysis are conflated. From a distal evolutionary perspective, altruism refers to the way altruistic alleles (genes) are selected among different populations within a species in competition with selfish genes1. From a proximal psychological-motivational perspective, altruism refers to way an altruistic gene activates or deactivates specific altruistic motives and behaviors within individuals. For example, let’s say that through a distal process altruistic gene(s) are selected because they confer greater survival value to those individuals who have this gene(s) than to those individuals who don’t. Through a complex biological process that involves the expression DNA regulated through epigenetic mechanisms such as DNA methylation (Szyf & Bick, 2013) that turn genes on and off, altruistic gene(s) will ultimately cause mothers who have these genes to experience powerful positive feelings toward their offspring, so that these mothers will be highly motivated to care and protect them, that is, proximal causation.

1 To simplify, most evolutionary models assume equivalence between an allele (altruistic or selfish) and a corresponding

behavioral trait. This deterministic view is, of course, incorrect. Any phenotypic expression of genes, such as a complex altruistic trait, requires the coordination of many genes that are turned off and on during development by epigenetic mechanisms. The simplistic model serves as an approximation and can be made more complex yet arrive at a similar conclusion. But sometimes this seemingly benign assumption can be very misleading and obscure possibilities for altruistic expression (see Sober and Wilson, 1998, pp. 105-106).

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Some models of selection are altruistic in an evolutionary distal sense but not in psychological-motivational proximal and some forms of cooperation are not altruistic at all. Kin selection is an example of the former. Some evolutionary theorists question whether kin selection is “truly” altruistic since it is based on the selection of altruistic genes among individuals who have close kin ties. From this distal perspective, some argue that kin-based selection is a prime example of genetic nepotism “selfish genes” pursuing their own reproductive ends through altruistic means (Dawkins, 1976/1989). However, if we look at kin selection from a proximal psychological perspective, helping behaviors between close kin are clearly altruistic. Take the example of mothers and their offspring that we just mentioned. Maternal instincts can be quite fierce, and mothers of many species of mammals (including humans) and birds will sacrifice their lives defending their offspring from predators or from other serious threats.

Reciprocal altruism (Trivers, 1971) is an example of a conditional form of cooperation that is not altruistic in a distal nor in a proximal sense, and many think the term is a misnomer. Reciprocal altruism is a direct form or cooperation based on a conditional strategy “I will help or cooperate with you if you help or cooperate with me, but will stop cooperating as soon as you do not reciprocate”. This strategy helps explain how many forms of cooperation might have evolved (particularly in the human case as we will see), but from a distal perspective this form or mutualism does not involve a sacrifice for the reciprocating pair, hence by definition it is not altruistic. From a proximal psychological-motivational perspective, reciprocal altruism it is not based on an altruistic motivation, but rather on a pragmatic-utilitarian calculus in which individuals select counterparts who “play fair”, a calculus that does not involve sacrifice. To avoid confusions in regard to altruism and cooperation, it is important to keep in mind the distinction between distal and proximal levels in the analysis of causation.

We will be addressing two forms of cooperation. One form of cooperation might be described as a form of enlightened self-interest. We cooperate because it is mutually advantageous to do so. Another form of cooperation is prosocial. The extreme example is saving the life of a person even at the cost of our own life or taking it upon oneself to sanction or expose violations of shared social norms (the whistle blower). We usually think of these peoples as heroes, but here are myriad examples of less costly forms of prosocial cooperation that we see routinely such as taking the time to give direction to a stranger, giving a seat in a train or bus to an older person, mentoring a colleague, helping a neighbor by shoveling his walkway. We often engage in these prosocial behaviors for no other reason than the pleasure it provides us. The motivation is intrinsic (we will referring to this prosocial motivation as a cooperative and social engagement system) and we are not necessarily looking for recognition or expect reciprocity, although we all recognize that a mixture of motives is often the case. Humans excel in this form of prosocial cooperation. But not only is it a matter of the quality of cooperation, it is also a matter of quantity and scale. Human cooperation is not limited to dyadic or small group interactions and involves large-scale enterprises such engaging in warfare, creating institutions, multinational commercial transactions or large-scale scientific projects across international boundaries. Perhaps with the exception of a few highly social insects such as ants, bees and termites, this type of large-scale cooperation and social complexity is unparalleled in the natural world (Wilson, 2012). Explaining how this type of prosocial cooperation evolved in our species is a central theme of this essay.

Steps toward ultracooperation and the emergence of the human mind There are many sources of evidence demonstrating the ultracooperative nature of our species, such

as experiments conducted by behavioral economists using social games that present people with social dilemmas (game theory) such as the ultimatum game, the prisoner’s dilemma and social goods games. These social dilemmas pit cooperation and altruism against self interest and show just how widespread norms of fairness and altruistic cooperation prevail in many societies and cultural groups around the

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world (for a summary see Bowles & Gintis, 2011, pp. 19 -20; Henrich et al., 2005). Other source of evidence are studies comparing between African apes and humans in terms of cooperation and competition under various experimental conditions (for a summary of these studies see Tomasello, 2009). It is only when converging evidence coming from multiple sources begin to support a particular thesis that we can have confidence that we are on the right track. We think this converging evidence overwhelmingly points toward the ultracooperative nature of our species.

In this section we provide a very condensed explanation of how four interrelated evolutionary strategies worked to produce an ultracooperative type of social organization, and a strong motivation to develop affiliative ties with kin and nonkin members of nomadic hunter-gatherer societies. We will also explain how and why these evolutionary strategies put strong selective pressures for the development of intersubjective abilities that helped in communicating and sensing into the minds of others (empathy). These four evolutionary strategies are: 1. A system of cooperative care by which parents, as well other members of the group who are not

genetically related to the infant, assist mothers in the care and provisioning (feeding) of young children. The caregivers who are not genetically related are referred to as “alloparents or allomothers” (from the Greek allo which means other). This socio-biological system of care is formally known as cooperative breeding.

2. A type of sexual bonding (pair bonding) that led to more stable and durable ties. 3. A type of cooperation that led to the emergence of shared egalitarian social norms. 4. A very prolonged period of development (the most prolonged of any known species) that supported

developmental plasticity and adaptive flexibility.

An extension of the caregiving system (or why “it takes a village”) Cooperative breeding was first studied in some species of very social (“eusocial”) insects such as

ants, bees and termites (Wilson, 2012) but it is its presence in primates that makes it significant for understanding human evolution (Hrdy, 2009). According to Hrdy alloparental care “is accompanied by provisioning in approximately one fifth of primate species, even though with the exception of human and some Callitrichidae (the galago and ruffed lemur nestmates who allow one another’s young to suckle for example), such provisioning is fairly minimal…. the remarkable thing about humans, then, is not so much cooperative breeding, it is cooperative breeding in an ape –and the highly unusual traits that emerged as a consequence of this unprecedented combination” (Hrdy, 2009, p. 275, authors italics).

In the majority of mammal species, only mothers care for their offspring until they become independent (“independent breeders”)2. For instance, chimpanzee mothers will not allow other members of the group even to get close to her infant in the first six months of life. The high level of trust required for mothers to allow allomothers to take care and help with feeding their young is extraordinary given the high levels of infanticide that exists among many species of primates (Hrdy 2009). Infanticide among chimpanzees and gorillas is common, as it is in other primates. For instance, Cheney and Seyfarth (2007 pp. 40-41) report that infanticide exceeds predation as the major cause of death among baboons. While there is no unitary explanation for infanticide in primates, most evolutionary thinkers attribute it to the very nature of very competitive societies in which primates live, and an impulse to get rid of potential rivals. Another factor is that Great apes have a strong taste for red meat, and unprotected infants are an appetizing source of proteins and fat. As we will explain shortly, with the gradual shift toward more durable pair bonding among our hominin ancestors, males began to

2 A recent article on bonobos is beginning to modify our view of the social life of African apes, by showing that bonobos

will share food with strangers as long as the are engaged socially with them (Tan & Hare, 2013).

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participate in the care of the young, an extension of the protective role that had been exclusively maternal (Chapais, 2008) and greater tolerance between males begins to develop. The net effect is a diminished threat of infanticide that allows mothers to let others assist in the care and provisioning of their offspring.

Specialists in the field attribute the emergence of cooperative breeding strategy to environments in which there are extreme climatic changes (Hrdy, 2009). Hrdy believes that these were the conditions that prevailed during the Pliocene-Pleistocene transition 2 million to 1.8 million years ago when Homo erectus appears in the paleontological record. H. Erectus had a brain of 900 cc, twice the size of our australopithecines ancestors, and the first Homo species with a modern anatomical structure that allowed for long distance traveling. Drastic climatic changes characterized by severe fluctuations in rainfall would have forced this early Homo ancestor to shift in childcare in order to feed the young with a large brain that consumed enormous amount of energy, and allomothers became a necessity to help feed these young and very mobile youngsters (Hrdy, 2013). As Hrdy emphasizes, long before cultural and behavioral modernity appears among Homo sapiens approximately 80,000 years ago (Balter, 2011) our Homo ancestors might have already achieved a significant degree of prosocial behaviors, an “emotional modernity” of sorts (Hrdy, 2013). However, even full-fledged cooperative breeding is compatible with vigorous competition, and dominant hierarchies may have still played an important social role among our early Homo ancestors (Hrdy, 2013).

It takes 13 million calories to rear a human from birth to nutritional sufficiency (Hrdy, 2009, p. 101) and humans of all primates have the most costly, largest, slowly maturing infants. Alloparents bear heavy costs when they participate in the care and feeding of juveniles with whom they do not have a close genetic connection. What benefits could possible offset these high costs? Human mothers that are freed from the exclusive care and feeding of their young can begin to participate more fully in foraging activities, and this participation might have had a large impact on the survival of these small nomadic societies. At least half of the calories consumed by hunter-gatherer societies come from the foraging activities of females (Hrdy, 2009, p. 106- 107). Females contributions, particularly the role of post reproductive women, has been well documented in several ethnographies of extant nomadic hunter-gatherer societies (Hawkes, 2004; Sear & Mace, 2008). Humans live longer than our African ape relatives and our extinct hominin relatives, the Neanderthals (Thompson & Nelson, 2011). A longer life span means a longer postreproductive period. Rather than remaining idle, postreproductive women participate actively in the care of their grandchildren and other children that are not closely related family members. This is known as the “grandmother hypothesis” brought to our attention by Kristen Hawkes (Hawkes, 2004), yet another link in the chain of events that led to cooperative breeding. We agree with Hrdy that females’ contributions to contributing to the survival of our hominin ancestors is an important part of the prehistory of our species that has not received the attention it deserves. But its significance is becoming evident in developmental agencies from around the world that serve impoverished communities. Supporting women’s education and ability to participate actively in the economic life of their communities is one of the best ways to lift these communities from poverty3.

There is another factor that helps explain why cooperative breeding might have taken hold among our human ancestors. While lactating, mothers are generally less fertile, and alloparenting allows human mothers to wean their babies earlier and make them available for having another infant. Chimpanzees who do not have this help wean their offspring until they are 5 or 6 years old. This has a very large impact on fertility rates of human mothers in comparison to our chimpanzee relatives. Before modern contraception methods were introduced to nomadic hunter-gatherer societies, human mothers conceived on an average of every 3 years, while chimpanzees conceive an average of every 6 to 7 years (Hrdy 2009).

3 World Bank. Report on Gender, Equality, and Development (2012).

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Cooperative breeding promotes the development of intersubjective communications As significant as the effects of cooperative breeding are for the micro economies of nomadic

foragers and the fertility rates of human mothers, the effects on the development of infants’ communicative abilities might have been of even greater evolutionary significance. Having many alloparents with whom to interact at an early age might have been the main factor that accelerated the development of infant communicative abilities and an important piece of the puzzle of why humans intersubjective abilities and communication are much more developed than in other primates. This is quite evident early in development as can be observed by the charming “proto-conversations” between mothers and infants and their the back and forth “ooing and aahing” (Bateson, 1971; Beebe & Lachmann, 2002; Trevarthen, 1980).

There are several sources of evidence that support the idea that an early enriched social environment has profound effects on the development of intersubjective communication and the ability to understand the perspective of others later in life. Hrdy (2009) notes that when chimpanzees are raised in captivity or in close contact with humans, they develop many more abilities to communicate than those observed in their natural habitat. For instance, chimpanzees don’t point in the wild, but chimpanzees that are raised by humans often learn to use pointing to make requests, although they never learn to point for the sake of sharing an object with others, as human infants do by the time they are 12 months old. (Tomasello, Carpenter, & Liszkowski, 2007). When infant chimpanzees are exposed to the rich type of social interaction provided by humans, it pushes the limits of chimpanzees’ capacity for intersubjective communications to unsuspected degrees.

Tetsuro Matsuzawa at the Primate Research Center at the University of Kyoto had worked with Ai, an African-born chimpanzee over the course of thirty years, and so gained her trust that Ai did something that chimpanzee mothers would never do in the wild. She let Matsukawa have access to her first-born infant Ayumu. Matsuzawa was immediately rewarded by being able to make an important observation. Like human infants, Ayumu had REM induced smiles while she was asleep—sometimes referred to as a “practicing” smile. But a few weeks after birth Ayumu began showing a social smile, and she kept smiling to Matsukawa and her mother with full-blown social smiles, much like human babies do, a behavior between mothers and infants that had not been recorded in the wild before. One of Matsuzawa’s students, Masako Myowa thought that if babies were smiling early on, they might also be able to imitate gestures as Meltzoff and Moore’s famous experiments had shown in human newborn babies (Meltzoff & Moore, 1977). Using the same intuitive approach she learned from her teacher to probe the extent to which chimpanzees can interact socially after birth, Myowa was able to show with an infant chimpanzee that had lost her mother soon after birth, that they could protrude her tongue and imitate Myowa’s funny gestures. But there is a catch to this story. The Kyoto Primate staff repeated the same experiment with other newborn chimpanzees, and the infant chimpanzees continued to smile back and imitate their human caretakers. But suddenly at 12 weeks, the infant chimpanzees seemed to lose interest in their humans’ smiles, silly faces and gestures and stopped smiling and imitating them. It seems that the Kyoto group had pushed a type of social interaction to its very limit. Infant chimpanzees get close, but they cannot bridge the 6 to 7 million-year gap when chimpanzee and our hominin evolutionary paths began to diverge.

Supporting this view is the remarkable observations made in colony of rhesus monkeys located in Poolesville, Maryland headed by Stephen Soumi and colleagues (Ferrari, Paukner, Ionica, & Suomi, 2009). The team observed and recorded a type of intersubjective sharing and eye gazing in mother-infant dyads that begins soon after birth. This form of intersubjective exchanges was thought to be rare or nonexistent among nonhuman primates. But after a month this type of intersubjective communication suddenly stops. At that age, infant monkeys begin to interact with their peers in rough and tumble play. Soumi speculates that this type of intersubjective communication does not serve a useful purpose in rhesus monkeys in which peer relations prepare juvenile members to adapt to dominance hierarchies that play such a major role in their social life (personal communication with the

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first author). Extensive alloparental care might have started us in this evolutionary path by providing the babies of our human ancestors with many opportunities for rich social interactions. As this intersubjective matrix began taking hold generation after generation through cooperative breeding, (and aided by the need to cooperate equals) it put us on an evolutionary path that led to the development to the ability to understand the intentions emotions gestures, and eventually, the minds of conspecifics (members of the same species).

Burkart and van Schaik (2009) developed another line of research that strongly supports the hypothesis that cooperative breeding and alloparental care led to more advanced forms of intersubjective communication and social cognition by comparing three closely related species of new world monkeys that vary in the degree to which they exhibit alloparental care. The first group of species, the tamarinds and marmosets, belong to the Callitrichid family and are full-fledged cooperative breeders combining care for the young with provisioning. The second species, the capuchin monkeys belong to the Cebine family and exhibit a modest degree of shared alloparental care with minimal provisioning. The third species, the squirrel monkeys – also members of the Cebine family – alloparental care is very limited or nonexistent (they are independent breeders). Burkart and van Schaik predicted that tamarinds and marmosets would outperform squirrel monkeys (independent breeders) in social cognitive measures but not in nonsocial cognitive tasks. Capuchin monkeys, who exhibit some cooperative breeding behaviors, would be in the middle. It was also predicted that the Cebine family of capuchin and squirrel monkeys would outperform tamarinds and marmosets in the nonsocial domain, due to the fact that they have a larger brain size relative to their body size—general intelligence and larger brains are in general highly correlated (Deaner, van Scahaik, & Johnson, 2006).

To compare social cognition (intersubjective abilities) they used 5 measures: attentional bias, gaze understanding, visual contextual learning, plasticity of vocal calls, and teaching-like abilities. To compare nonsocial cognition they used 7 measures such as tool use, stages of object permanence (as defined by Piaget) working memory and responses that require delayed gratification in order to solve a problem. Consistent with the hypothesis, tamarinds and marmosets systematically and significantly outperformed their capuchin and squirrel monkeys in the social cognitive domain, but not in the nonsocial cognitive domain. It is important to emphasize that tamarinds and marmosets outperformed capuchin and squirrel monkeys in social cognitive measures despite having a smaller brain. As predicted, capuchin monkeys that have some elements of cooperative breeding are somewhere in the middle in social cognitive skills. This is a very significant confirmation of the hypothesis that alloparental care promotes the development of social cognitive skills that are needed for intersubjective communication to flourish.

It is very likely that the same phenomena has been at work with dogs, who have a long history going back at least 14,000 years or more of living with humans, and explains why dogs have some remarkable human-like social skills (Hare & Tomasello, 2005). Through a process akin to domestication, human infants, raised and exposed for hundred thousands of years to multiple caregivers were able to develop intersubjetive skills that helped human communications and social understanding (Hrdy, 2009). It is also from this fertile intersubjective ground that language and the ability to sense into (and imagine) the minds of others was able to blossom. It is beyond the scope of this essay to explore the relationship between intersubjectivity, imagistic and perspective-taking abilities that are implicit in concepts such as theory of mind, mentalization and empathy (see Cortina & Liotti, 2010; Hobson, 1998, 2004; Tomasello, 2008; Trevarthen, 1980).

How enduing sexual pair bonds (pair bonding) contributed toward the type of family structure and group composition observed among hunter-gatherer societies

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Chimpanzees and bonobos live in large mixed sex groups that mate promiscuously and have short term mating patterns. Males and females copulate with several mates and there is no stable breeding bond (Chapais, 2008). When the females reach sexual maturity they move to new groups (their species solution to the incest problem), while the males stay in their natal group. In chimpanzees this social organization leads to extensive patrilines of males that include grandfathers, fathers, uncles and brothers. Remarkably, these patrilines do not recognize themselves as kin so that this genealogical structure is “socially silent” (Chapais, 2012). The significance of this lack of kin recognition is that it makes other males potential rivals. Chimpanzees do not form “friendships”, at best they develop strategic partners to protect their rank or use these alliances to take over higher-ranking individuals (de Waal, 1982). Grooming plays an important role in this process by softening conflicts, and by helping create and maintain new alliances (de Waal, 1989). Sometime during the course of human evolution longer term pair bonding between males and females and stable breeding patterns emerged as an evolutionary innovation – an innovation that has occurred in other species of primates and birds but is rare. According to Chapais, the most important consequence of long lasting pair bonding is that as fathers begin to participate in the caregiving of their offspring they begin to recognize them as “one of their own” –and vice versa. Slowly, pair bonding begins to reveal the underlying genealogical structure of kin relations. For instance, if a daughter forms a pair bond with a male from another group, the father can now recognize his daughters preferred mate as an affine, that is, as a familiar individual who can be tolerated and doesn’t pose a threat to his exclusive relation to his mate. Other effects of enduring pair bonds became extended to sibling relations and to maintaining family relations when family members migrate to other groups because of marriage or other reasons. The combined effect of these evolutionary innovations brought about the multifamily composition of humans, a kinship system probably emerged in fits and starts among our hominin ancestors. This extension of social recognition among group members began to create a state of mutual tolerance among males and possibilities for cooperation that had not existed before. In this growing social network, males were able to circulate more freely between groups (Chapais, 2008). The ability of band members to interact with other members of hunter-gatherer groups created possibilities for commerce, mutual learning, and as we will see later, mutual aid in times crisis. The resulting accumulation of cultural knowledge led to the emergence of behavioral and cultural modernity during the Late Pleistocene period (Tomasello, 1999, 2008).

A study of 37 nomadic hunter gatherer groups (n = 5067 individuals) from all over the world by Hill and the co-authors (Hill et al., 2011) confirms Chapais predictions of the composition of multifamily groups in nomadic societies, as well the effects on the development of kinships networks and of residence and co-residence patterns (who stays or leaves a group and how stays in contact ). Contrary to what we see among other primates, when family members do stay in their natal group (such as brothers and sisters) they often maintain life long ties. The significance of enduring sexual bonds for human evolution is that it supported the formation long-term relations that are necessary to sustain cooperation over the long haul. The net effect was to produce changes in residence patterns within natal groups, and large interactive networks of family related and unrelated individuals between different groups.

We close this section on pair bonding with two points. First, the emergence of long-term pair bonding should not be read as implying that monogamy is normative for our species, and that other mating systems or institutions such as polygyny (one male to several females) or polyandry (one female to several males) are aberrant. Different species and different human cultures have produced many types of mating systems that have proven to be adaptive. Second, anthropologists have generally have held the view that small bands of nomadic hunter-gatherers were composed almost entirely by kin, and the high degree of altruistic cooperation observed in our species has generally been explained by kin selection (sometimes referred to as inclusive fitness, see below). But the Hill et al., study shows that most members within small nomadic bands are not kin-related, and that “these patterns produce

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large interaction networks of unrelated individuals and suggest that inclusive fitness cannot explain extensive cooperation in hunter gatherer bands (Hill et al., 2011, p 1286).

From hierarchy to egalitarianism (or how nomadic hunter gathers got rid of bullies and solved the free rider problem)

During more than 95 % of the life of our species (200,000 years) we have lived as nomadic hunter-

gatherers, or over 99 % if you start counting with the appearance of Homo erectus 1.8 million years ago, considered by many our first fully Homo ancestor. To understand human evolution it is essential to have an approximate idea of what that nomadic life might have been like. Human behaviors and attitudes do not fossilize, and any understanding has to be come from the very scant traces of fossilized bones and artifacts left behind and ethnographic studies of modern nomadic foragers that have had minimal contact with modern civilization (Boehm, 2012; Boehm, 1999; Hill et al., 2011). Ethnographies of extant nomadic hunter-gatherer societies serve as the closest model we have as how human hominin ancestors lived and survived during the Pleistocene—particularly during the Late Pleistocene when cultural and behavioral modernity makes its appearance in the archeological record.

If Sarah Hrdy is the undisputed champion in highlighting the importance cooperative breeding had in evolution of our species, Christopher Boehm has played a similar leading role in helping us understand how and why our human ancestors were able to transition from a social organization primarily based on dominance hierarchies to a highly cooperative social organization based on a shared egalitarian ethos that emerged sometime during the Pleistocene era. Boehm brings a unique skill set to this endeavor. Trained as a cultural anthropologist, he did field work studying egalitarian tribes in New Mexico and in the Balkan mountains of Montenegro and was trained by Jane Goodall, the legendary pioneer in studying chimpanzees in the wild (Goodall, 1986). Boehm has continued the work of Goodall doing annual field trips to the Gombe national park in Tanzania.

Boehm (1999, 2012) has carefully reviewed the ethnography of 339 nomadic hunter-gatherers studied by anthropologists in the past, selecting and weeding out cases that had significant contact with modern civilizations or missionaries or used horses. Boehm also eliminated ethnographies of large groups of nomadic hunter-gatherers and cases in which nomadic foragers spend time in a permanent village. That left 150 cases, a which a third that have been systematically coded and studied by Boehm and made the final cut for cases that most likely resemble our “late Pleistocene appropriate foraging societies”. These nomadic foragers live in mall bands of 20 to 50 individuals comprised, as we just mentioned, by multi-family groups as well as group members that are kin related. The most significant findings from this review – that confirms what most anthropologists have come to believe – that despite huge differences in climates, from frigid Arctic tundra to sweltering tropical forests, and many cultural differences, without exception all nomadic groups are fiercely egalitarian and “as nomads, instead of trying to store their large-game meat as individual families, they share it widely …and they always combine hunting to make a living according to what is environmentally available” (Boehm 2011, pp.79-80). According to Boehm, the ethnography of these corresponds to what is known of the archeological record of Late Pleistocene ancestors. These facts alone beg for an evolutionary explanation.

Anthropologists have noted similarities between contemporary hunter gatherers and what is known of our late Pleistocene ancestors, including similar hunting tools such as stone flakes attached to wooden shafts, harpoons, traps and nets, sometimes described as “gadget technologies” (Kuhn & Stiner, 2001). But what perhaps comes closest to a “smoking gun” in anthropology, showing evidence of cognitive and cultural continuity between nomadic hunters over a span of 40,000 years or more, has been the recent discovery by d’Errico and his team of many artifacts found in the Border Cave, near the border of Swaziland in South Africa (d’Errico et al., 2012). All these artifacts and bones have been

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carefully dated and are between 39,000 to 44,000 BP. They include bone tools shaped in long shafts, (probably used to scrape meat from bones), that are finely decorated in the form of a spiral with red pigment, and beads made of ostrich eggshells used as necklaces. Other artifacts found are “digging sticks” and a “stick” bearing traces of a poisonous compound –similar to a tool used by the bushmen of the Kalahari desert to apply poison in their arrows. In addition 4 bones with notches were also found, that the team interprets as “tally sticks” used for counting. All these artifacts are remarkably similar to the art work and hunting tools used by contemporary bushmen people in Africa, and show that the inhabitants of the Border Cave in South Africa had achieved a level of cultural and technological sophistication that matches contemporary bushmen of the Kalahari desert (Balter, 2012b). These recent discoveries support Boehm’s speculation (2012) that the transformation toward a highly cooperative and egalitarian type of social organization took place during the late Pleistocene approximately 45,000 BP, but it might have been even more ancient given recent discoveries in South Africa dating 77,000 BP (Balter, 2011).

Equipped with an anatomy adapted to travel long distances, Homo erectus (1.8 million years BP) was able to adapt to life in the open African savannah. Soon after its appearance in the paleontological record, groups of Homo erectus were able to leave their African homeland and reach as far as eastern Asia in Java and China (Tattersall & Schwartz, 2000 pp 148-154). Hand axes that were used to carve meat from carcasses are present in these sites, but the “tool kit” is quite limited, so it was probably not a technological innovations that allowed for these early hominins to leave Africa (Tattersall & Schwartz, 2000). Most likely the emergence of a modern body that allowed Homo erectus to travel long distance, a larger brain and an emotionally more modern social organization in which cooperative breeding perhaps played an important role (Hrdy, 2013) were all factors that allowed these very primitive humans to leave Africa. The open Savannah brought new dangers and new opportunities. The need to develop highly cooperative bands that could share the spoils of animal scavenging with other members of the band and protect against much more powerful predators became essential for survival. Recent paleontological evidence estimates that the shift from scavenging to cooperative hunting of large ungulates (large hoofed mammals) might have taken place 1.3 million years ago, based on an analysis of over 1000 animal bones led by the Spanish paleontologist Manuel Dominquez Rodrigo in the fossil-rich Olduvai Gorge in Africa (Balter, 2010b). It is not hard to imagine how cooperative breeding and collaborative hunting might became the basis of an egalitarian form of life that might have appeared much later with anatomically modern Homo sapiens (200,000 years ago) or behaviorally and culturally modern Homo sapiens that first appear in Africa approximately 80,000 years ago. At this moment there is no way to know if egalitarian foragers might have emerged even earlier among more primitive humans. Based on the ethnographies surveyed by Boehm, was is clear is that among nomadic hunter gatherers, any attempt by other members of the group to take advantage of this system of sharing by not reciprocating in kind (the “free rider problem”), or trying to dominate the group (aspiring alphas and bullies), are immediately ridiculed or punished through different means, including shaming, ostracizing, and in extreme cases by murder (Boehm, 1999, 2012). The role of the family of emotions that include shame, embarrassment, guilt and pride are powerful socializing tools that we and others think had a major impact in contributing to an egalitarian form of life among ancient nomadic foragers (Gintis, Bowles, Boyd, & Fehr, 2005; Henrich & Henrich, 2007). Evolutionary models show that the punishment of free riders, bullies and sociopaths is critical for an altruistic form of cooperation to evolve, but the punishment of bullies or free riders can carry very large costs if left to a few individuals who singlehandedly confront free riders or bullies (Gintis, 2003; Gintis, Bowles, Boyd, & Fehr, 2003; Henrich & Boyd, 2001).

For now we want to examine the problem from a psychological (proximal) perspective to show how the emergence of shaming emotions during human evolution very likely went hand in hand with the emergence of shared social norms that support communal values of equality and fairness (Gintis, 2003; Gintis et al., 2003; Henrich & Henrich, 2007). Later on we will examine genetic models that explain

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how these helping and altruistic behaviors could have evolved. The proximal argument is straightforward. Shared prosocial norms act like a social tax that is imposed on all members of the group (Boyd, 2006) and make the cost of sanctioning free riders and bullies a less costly proposition for any single individual who would act on his own. The “tax” idea is Boyd’ s way to explain a proposal by Samuel Bowles idea of “reproductive leveling” (Bowles, 2006). The “leveling” effect is created by cultural influences, such as shared social norms, that support equality and fairness and “level” the playing field for cooperative altruists. This is an example of gene- cultural evolution where humans begin to create their own social environments that favor the selection of individuals who carry altruistic genes (Boyd & Richerson, 2005) (Boyd, Richerson, & Henrich, 2011a).

For shared social norms to have a major role in creating social change it is important that these norms become internalized as a set of mostly autonomic (unconscious) expectations. Once internalized, shared egalitarian values support the collective sanctioning of free riders and bullies by shaming and ostracizing those members who deviate from the shared ethos (Boehm, 1999). Shared social norms function by acting as a social glue that hold groups together by creating a sense of cohesiveness and group identity, in what Choi and Bowles (2007) have called a “parochial” identity that is the basis for an “us versus them” mentality.

The idea of “internalized” shared values has been modeled mathematically by the evolutionary economist Herbert Gintis (2003). The importance of shared social norms, values and attitudes was introduced to social psychology by the psychoanalyst Erich Fromm (Fromm, 1941) who tested this theory empirically a few decades later (Fromm & Maccoby, 1970). Fromm called these shared values and emotionally based attitudes “social character”. The main idea behind the theory is that a set of character based (emotionally-based) attitudes and values became shared by large number of individuals within a group or social class. According to Fromm “social character internalizes external necessities and thus harnesses human energy for the task of a given economic and social system” (Fromm, 1941, p. 284). In effect, people end up “wanting to do what they have to do” to prosper and survive under certain cultural and economic conditions (Fromm and Maccoby, p. 18). According to Fromm, shared attitudes and values are instilled by families, who function as “psychic agents of society” (Fromm, 1947 p. 68) and are internalized through a process socialization and assimilation that begins early in development and are reinforced by social institutions and ideologies (Fromm 1941, Fromm and Maccoby, 1970). Developmental research has confirmed Fromm’s view that social norms are acquired very early in life, and children as young as 2 to 3 years of age adopt a “normative stance” in their relations with others and actively enforce social norms (Rahoezy & Schmidt, 2013).

Despite the existence of internalized values, there will always be individuals who defy or will not conform to these norms, and different types of sanctions or punishments are necessary to bring these individuals in line. Shared values and social sanctions support each other. Shared norms ensure that the cost of sanctioning does not fall on the shoulders of only a few individuals. Different forms of shaming, maintaining social reputations, and the threat of ostracism are sufficient to keep most trouble makers in check, as shown so clearly in ethnographies of hunter gatherers quoted by Boehm (1999). Michael Maccoby (personal communication) notes that shame would not have its power if it weren’t intimately connected with a sense of human dignity, and Maccoby includes human dignity is his list of what he calls basic value-drives (Maccoby, 1988).

Two caveats are in order. First, the argument being advanced is not that all shared social norms are adaptive and prosocial. We only have to look at the horrific example of Nazi Germany to show how a shared ideology based on wounded national pride and the invidious scapegoating of minority groups can lead to genocide and self-destruction. In a study done in the 1930’s that used an in-depth psychoanalytic interview, Fromm showed that a very small percentage of white and blue-collar German workers surveyed shared strong authoritarian and sadistic attitudes that contradicted their manifest leftist political beliefs. Another small percentage shared strong anti-authoritarian democratic attitudes. The rest of the population interviewed showed a mixture of authoritarian and democratic attitudes and

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did not have strong convictions. Based on these results Fromm predicted that this large group would conform to the prevailing ideology and that could not be counted on to resist Nazism and its nationalistic, authoritarian and hateful appeal (Fromm, 1984). Second, maintaining adherence to shared values through different forms of shaming and threats of ostracism work informally (and effectively) in small groups such as simple hunter-gatherer, pastoral or horticultural societies. The evolutionary psychologist Robin Dunbar (2010) found that informal social systems work when they are limited to approximately 180 people (“Dunbar’s number”). Sanctioning in complex societies with large urban centers requires formal institutions to be effective, but there has to be enough of a common ground of shared values for institutions to have legitimacy, and institutions have to be perceived as having sufficient integrity for people to trust them. When these bonds of legitimacy and trust break down, societies begin to descend into anarchy and chaos. But without the emergence of shared social norms, the power of shaming emotions and social reputations, and threats of punishments such as ostracism, it would be hard to understand how and why prosocial motives and behaviors, that are strongly supported by many religious and legal institutions, could have emerged in our species.

Life history strategies support developmental plasticity and adaptive flexibility Life history strategies (LHS) that tinker with the shortening or lengthening of developmental periods

and the initiation and termination of developmental phases can have major evolutionary impacts and are frequently observed in the evolution of many species. Humans are no exception, and LHS have played a major role. According to Thompson and Nelson “nonhuman primates are considered to have four major life history strategies: infancy, the juvenile period, a short adolescent period and the adult stage…modern humans have “inserted” an additional stage: early childhood, which falls before the juvenile period, and they greatly elongated their adolescent stage” (Thompson & Nelson, 2011 p. 249-250). In addition, humans wean their infants earlier than chimpanzees and have a longer postreproductive period. The shorter weaning period in humans is connected with cooperative breeding. As other members of nomadic hunter-gatherer groups participated in the feeding of infants, human mothers were able to wean their infants earlier—till the age of 3 among nomadic hunter-gatherers. In comparison, chimpanzees wean their infants until they are 6 years old. Following the weaning period around the age of 3, humans have added an early childhood stage (three to five). Adding an earlier childhood period to middle and late childhood has kept these childhood stages roughly equivalent to the “juvenile” period of chimpanzees and bonobos. Adolescence in humans is very prolonged in comparison with our ape relatives and even in comparison with our closest hominin relatives. Chimpanzees reach full sexual maturity and are fully developed by age 12, approximately the same age as when Homo erectus reached sexual maturity. In contrast, humans reach full sexual maturity by the age of 18, by far the latest of any known species. Recent evidence shows that Neanderthals, who had brains as big or bigger than humans, reach sexual maturity by age 14. Interestingly our extreme form of elongated adolescence does not appear until the appearance of modern Homo sapiens roughly 200,000 years ago (Hopkin, 2005). Clearly, brain size alone does not explain the differences between humans and Neanderthals, and the finding that humans have a more prolonged adolescence and slower maturity than the Neanderthals suggest that the prolonged adolescence was selected to increase developmental plasticity of the brain and allow children and adolescents sufficient time to absorb the enormous amount of learning that is necessary to function as adults in rich cultural environments that humans are continually recreating.

In addition to adapting to their natural environments, some species create their own environments. This is the important phenomenon of niche construction (Kendal, Tehrani, & Oding-Smee, 2011). Bees create beehives, beavers create dams, and ants create a complex interconnecting labyrinth underneath their ant holes. These niches are more or less static and do not change once they are made. In contrast

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humans create cultural environments that are constantly changing. The emergence of a cultural form of evolution created strong selective pressures toward making changes in LHS that supported developmental plasticity and adaptive flexibility (Bjorklund & Rosenberg, 2005).

Conclusion

Cooperative breeding and the development of enduring sexual bonds have emerged in species with small brains and without the benefit of the extraordinary accumulation of cultural knowledge we see in humans. Cooperative breeding and pair bonding might have jump-started a new cultural form of evolution. Why were hominins able to build on cooperative breeding and not tamarinds or marmosets? These new world monkeys have very small brains, while our common ancestor with chimpanzees and bonobos already had a very large brain—approximately 400 cc (Hrdy, 2009). Hrdy believes this might explain why cooperative breeding (and we would add pair bonding) among ancestral hominin species may been able to evolve even more sophisticated cooperative and prosocial behaviors that led ultimately to intersubjective “mind reading” abilities. Life history strategies had a major impact facilitating these changes by delaying sexual maturation and creating a very elongated period of development that gave children and adolescents time to assimilate and learn a vast amount of cultural knowledge needed to function as adults. All these cooperative trends put selective pressures on creating better modes of communication that preceded the emergence of language. Humans who anatomically would be identical to us appear approximately 200,000 years ago in Africa (Hopkin, 2005). It took 100,000 years or more before human populations reached a level of density that allowed them to interact and learn from each and imitate cultural innovations such as tool making, cooking skills, artistic skills and musical instruments that are the clear manifestations of cultural modernity4 (Powell et al., 2009).

Based on our survey of recent literature on human evolution we have suggested a sequence of events that seem plausible, but we may never be able to know how with any degree of certainty, when and in what order these and other different evolutionary and cultural innovations came together. As we learn more about the remarkable bonobos (with whom we share 98.5 % of genes) we need to question whether the origins of prosocial behaviors, such a sense of fairness, may have much more ancient roots with common ancestors 6 to 7 million years ago (de Waal, 2013). Moreover, there are other important cultural innovations, such as the harnessing of fire that appeared 800,000 BP that we have not discussed, that had a major impact on human evolution (Wrangham, 2009). Whether these story lines or others turn out to have staying power will depend, of course, on new discoveries and new methods of inquiry.

Genetic models of evolution and the emergence of cultural evolution For the evolutionary strategies that we have described to have any credibility, they have to be

consistent with the theoretical work that has been formalized mathematically within the past 80 years. Mathematical models examine the basic conditions that allow natural selection to sort out whether individuals carrying cooperative and altruistic alleles (genes) will persist or will be wiped out by

4 The “full package” showing the emergence of cultural and behavioral modernity consists in the presence of symbolic

expressions such as abstract and realistic art, body decorations (threaded shell beads, teeth, ivory, ostrich shells, ochre, tattoo kits), systematically produced microlithic stone tools such as blades and burins, as well as grinding and pounding stone tools, functional and ritual bone, antler and ivory artifacts, evidence of improved hunting and trapping technology such as spear throwers, bows, boomerangs and nets, and last, but not least, the appearance of musical instruments in the form of bone pipes. The full package would have required that our nomadic ancestors were able to transfer raw materials over long distances (Powell, Shennan, & Thomas, 2009). The first evidence for cultural modernity in a less developed form appear in the tip of South Africa 77,000 BP (Balter, 2011), and later in Europe as full package 42,000 BP (Balter, 2012a).

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individuals carrying selfish alleles from the gene pool, or reach a stable dynamic equilibrium between both sets of alleles (McElreath & Boyd, 2007). These models help in pairing down the essentials, sometimes providing surprising insights. They then can be run as computer simulations and be put to the test with real life examples to see how realistically they conform to the natural world. While understanding the math helps, it is not essential, since these concepts can be translated into plain English.

Understanding the evolution of cooperation and altruism was named as one of the 20 most challenging scientific problems that remained to be solved, according to the editors of a special issue of Science (Kennedy & Norman, 2006). A growing consensus has been building toward a pluralistic perspective, identifying some key variables that led toward the emergence of altruism and cooperation. From this pluralistic perspective, different evolutionary models are seen as complementary rather than competing evolutionary strategies (Bowles & Gintis, 2011; Henrich & Henrich, 2007; Nowak & Highfield, 2011; Sober & Wilson, 1998). Within each species, different selection strategies come together providing a path toward cooperation and altruism. As Sherrat and Roberts note “The problem of cooperation has now many solutions and its existence can no longer be classified as a puzzle…. Eventually, theory and observation will meet and we then we will really know which general explanations apply to the world around us (Sheraff & Roberts, 2012, p. 1305)

We will briefly discuss four models that have been developed to explain human evolution: kin selection, direct forms of reciprocity, indirect forms of reciprocity, and a multilevel group selection model. We will begin with kin selection also known as “Hamilton’s rule” in honor of the legendary evolutionary thinker William Hamilton who as a graduate student published an article that revolutionized our understanding of the evolution of altruism (Hamilton, 1964). The general idea is that altruism could evolve through natural selection because it conferred benefits of the altruistic act to close genetic relatives. Consequently the altruistic act helps the proliferation of alleles (genes) associated with the altruistic act. Think of it as a form of genetic nepotism. The insight can be expressed formally by saying that conferring a fitness benefit of b to another individual will evolve by natural selection if the benefit of b is more than the cost of c to oneself:

b > c This relation is modified by a factor of r, (mathematically a “coefficient factor”), where r represents

the genetic relatedness between the actor or donor b and the beneficiary c. The values of r will vary according to the degree of genetic relatedness. One half for siblings, since siblings share 50 % of their parents genes (r = 0.5), one quarter for nieces and nephews (r = 0.25), and one eighth for cousins (r = 0.125). This general formula is expressed with a simple equation known as Hamilton’s rule:

rb > c The values for r will oscillate to close to zero for strangers to .5 for offspring or siblings, therefore

altruism will evolve as long a rb - c > 0. The closer the relative is to the donor the larger the fitness effect because the genes of the donor are passed on to the close relative (measured by the value of r) and therefore stays within the gene pool. Hamilton called this indirect benefit “inclusive fitness”.

Hamilton’s rule explains some, but by no means all cases of altruism directed at kin, such as the care of offspring by parents observed in many animals and among humans (see the discussion of Bowles and Gintis. 2012, pp. 48-50), but its importance is far more general. According to Bowles and Gintis, Hamilton’s rule “captures the key mechanism to all models of the evolution of altruism, namely that an altruistic gene cannot proliferate if its bearers are no more likely to receive help from those with whom they interact than would occur by chance” (Bowles and Gintis, 2012, p. 49). All successive models of the evolution of altruistic behaviors share this positive assortment feature in which altruistic and cooperative members interact with other members of a group who are likely also to be cooperative and altruistic. Depending on the species, positive assortment can be achieved through enforced physical proximity, as in the case of birds or queen bees or ants who build nests, or beehives, insuring interactions between cooperative and altruistic members within the confines of the nest or beehive

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(Wilson, 2012). Primates do not build nests, so after the weaning period, where offspring cling to their mothers, the positive assortment principle can be achieved through physical cues such as family resemblance and odors, but also through the experience gained by growing up together.

Altruistic members of a group who do not have close genetic ties cannot rely on physical proximity or physical cues to help recognize other altruists, and have to learn to recognize fellow altruists through other means. Direct forms of selection operate through repeated interactions. Altruistic members within a group learn quickly who is likely to reciprocate and who won’t and may develop Tit for Tat strategies to decide if they will maintain reciprocal exchanges with others (Axelrod & Hamilton, 1981). Indirect forms of altruism are sustained by identifying individuals with positive reputations for helping and cooperating with others. Individuals with positive reputations will attract other cooperative and altruistic members, who will also want to emulate them. Experience (and gossip in human communities), with effectively identify who are the givers and who are the takers (Alexander, 1987; Alexander, 1974). Ethnographies of nomadic hunter-gatherer societies reported by Boehm confirm that indeed, the power of reputations are important in these small societies where gossip plays a large role and everybody knows about others peoples’ business (Boehm, 2012). Interestingly, examples of direct and indirect forms of reciprocity have been mostly documented in humans (Henrich & Henrich, 2006; Henrich & Henrich, 2007) and very few examples have been observed in other social animals (Clutton-Brock, 2009; Hammerstien 2003). The reason why examples of direct and indirect forms of reciprocity are mostly confined to our species may have to do with the same reasons why the emergence of shared values was key for multilevel group selection to blossom (see below). Just as the emergence of shared values became a central step in supporting group level selection, the emergence of a moral order was equally important for rules of fairness that support direct forms of reciprocity (such as “Tit for Tat” strategies) or for the power of reputations (indirect forms of reciprocity). Boehm (2012) believes that morality emerged through the power of maintaining social reputations and imitating successful individuals. We think that the key factor was the emergence of shared values and social norms. Only when these values had become internalized did the power of reputations have an effect in shaping social selection processes. Many experiments done in different countries and different cultures show just how important and widespread norms of fairness are in the daily life of people in these different societies (Henrich et al., 2005).

All evolutionary models show that these ongoing interactions between cooperating individuals are essential to sustain cooperation on the long run. Without selective mechanisms, such as the ones we just described, individuals who are selfish or are free riders or dominant within the group will wipe out altruistic and cooperative individuals within groups within a few generations (Sober & Wilson, 1998, pp. 18-30).. Multilevel views of selection are based on the principle that selection can operate a multiple levels. At an individual level, free riders and selfish individuals will prevail in competition with altruistic cooperators, but selection at a group level (between groups) with favor groups who have more altruistic cooperators in the midst. For decades group selection was discarded as a realistic possibility since there were no possible scenarios that could explain how competition between groups could get going, given the strong selective pressures that strongly favor selfish individuals within groups. Group selection would never gain any traction (Williams, 1966). Moreover, Hamilton rule (kin or inclusive selection) and direct and indirect forms of cooperation were sufficient to explain the evolution of altruistic forms of cooperation among kin and among nonkin members (see Sober and Wilson, 1998, excellent discussion of these issues).

One way group selection could gain traction is if differential survival rates between groups become very significant. A review of the ethnographic and scant archeological data by the economist and evolutionary theorist Samuel Bowles shows that battles between nomadic hunter gatherer groups are much more frequent than was believed, and these conflicts can be quite lethal because of the nature of hand to hand combat (Bowles, 2006). According to Choi and Bowles (2007) the motivation to affiliate and identify with one’s own group led to a parochial form of solidarity and a tendency to see other

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groups as competitors or rivals. Supporting this view is an experiment using Oxytocin, a neuropeptide and hormone well known to enhance sociability. The neuropeptide was used in small groups of college students competing in game that pits one group against another. Groups that had been administered Oxytocin showed more in-group solidarity and out-group aggression than groups in which Oxytocin was not administered(De Dreu et al., 2010). Oxytocin might have been coopted during the course of evolution to produce this “us versus them” mentality that is clearly engrained in our species.

Bowles notes that his data can only go back to the late Pleistocene, 23,000 years ago, and any extrapolation to early periods is speculative. But absence of evidence is not evidence of absence, and the issue remains highly controversial (see the exchange of letters in the New York Review of Books between Steven Mitchen and E.O. Wilson Mitchen, 2012).

Even if it turned out that intergroup war was not an important player during human evolution during the lower and middle Pleistocene (2 million to 126,000 years), once cultural differences emerge, multilevel group selection clearly played a major role in the history of our specie (Bowles & Gintis, 2011; Boyd, Richerson, & Henrich, 2011b; Henrich, Boyd, & Richerson, 2012; Henrich & Henrich, 2006). Natural selection requires phenotypic variability, heritability and competition to work. It doesn’t matter whether variability is achieved through genetic mutations or through learned cultural traits, as long as the effects of mutation or learned traits are stable and endure (are heritable) from one generation to the next. Cultural differences and variation will produce competition between groups with different cultures, and cultures with more cooperative and prosocial members and norms will tend to prevail over less cooperative cultures. Genetically based selection and culturally based selection operate under the same principles but through different means, but the effects on the speed of change are dramatically different.

With socio-biological explanations such as cooperative breeding, as well as the recognition that the emergence of shared social norms that support prosocial behaviors may have played a major role during human evolution, it is now easier to conceive how selective pressures within groups that favor selfish individuals could have been neutralized and overcome. Through the pressure exerted by shared prosocial norms, groups with altruistic and cooperative individuals had a way of prevailing within groups, and selection between groups could gain momentum. And as this momentum grew, so did the selection of human populations who had more individuals who had prosocial motivations that were willing to make sacrifices for other members of their group, many which were probably not close family members. The idea is summarized by Gintis (2004):

«Cultural complexity and the rapidity of cultural change…render the internalization of norms fitness-enhancing, so the genetic predisposition to internalize norms is an evolutionary adaptation. Moreover, agents who internalize norms tend to punish norm violators. Thus, conformity to social norms becomes fitness enhancing, which renders the genes for prosocial emotions to be fitness-enhancing adaptations. The internalization of norms and the prosocial emotions permit large-scale cooperation among non-kin, setting the stage for the technological and cultural evolution characteristic of modern civilization» (p. 58).

The gene-cultural coevolutionary model is a product of many scholars and researchers that have

been building on each other work for the past 30 years (Boyd & Richerson, 2005; Cavalli-Sforza & Feldman, 1981; Durham, 1991; Lumsden & Wilson, 1981; Richerson & Boyd, 2005; Wilson, 2012). The model transcends fruitless debates in the social sciences as to whether human nature is hard wired, based on genes or the product of cultural differences. It is both; genes influence culture and culture influences genes. The end result is that cultural selection generates outcomes that are not seen in other animals and that are unique to our species (Boyd et al., 2011b; Boyd & Richerson, 2005; Wilson & Wilson, 2007)5.

5 Genetically based selection produces changes that move at a snail’s pace compared to cultural selection that produces changes at lightening speed. Moreover, these two forms of evolution influence each other. The evolution of altruism in

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Destructive conflict and war are not inevitable

Even if conflict played a significant role during the Pleistocene, warfare is not necessarily the only outcome. There is clear evidence from the groups of nomadic hunter-gatherers that have been closely studied by anthropologists within the last 80 years that they can and do engage in many forms of peaceful commerce (Weissner, 1982). In fact it was probably these exchanges between groups that allowed our nomadic ancestors to reach cultural modernity (that we will define shortly) during the late Pleistocene. Populations of hunter-gatherers grew very slowly during the late Pleistocene before they could reach a critical population density that allowed for ongoing exchanges among ethnically related tribes (Powell et al., 2009).

There is also evidence gathered by anthropologists living in the field with nomadic foragers that they can occasionally join forces when drastic environmental changes such as a prolonged drought threaten their survival. The anthropologist Polly Weissner was able to record these survival strategies first hand while living among the San people (the bushmen) in the Kalahari desert at a time when they were experiencing severe stress caused by a prolonged drought. To survive, these nomadic foragers made use of an elaborate system of gift giving that the bushmen call hxaro (Weissner, 1982). Weissner spent two years tracking the extensive hxaro networks and found that adults had an average of 16 stable partners with whom they exchanged gifts in their band and in other bands. Interestingly, most of these partners are not close kin, but can be distant family members or “adopted kin”. This elaborate system of gift giving shifted into high gear during the drought, and significantly mitigated severe hunger and starvation among the Bushmen. Weissner’s observations are regarded by many anthropologists as a likely scenario of how our human ancestors might have been able to cooperate and survive under similar conditions involving dramatic climate changes during the late Pleistocene (Balter, 2010a).

Over the course of human history there are many examples of ethnic groups that have lived in peace with each other and have profited by their interaction, and we have learned over the centuries some of the conditions that make this conviviality between ethnic groups and nations possible (Bonta, 1997; Wiener & Slifka, 1998). It is not written in our genes that we are destined to live in destructive modes of competition and rivalry. We can mix civilized modes of competition with cooperative efforts, large and small. Our layered genetic and cultural evolution is a curse and a blessing, and each generation must meet the challenge of transforming our “genius for good and evil” (Fromm, 1964) by bringing out in Lincoln’s famous words “the better angels of our nature”.

The fate of dominance hierarchies: the ranking system in our species For a good part of the prehistory of our species social hierarchies (the ranking system) was probably

actively suppressed and controlled, but they were not eliminated. What happened to dominance hierarchies in our species? After the Neolithic revolution – the domestication of plants and animals and the invention of agriculture 12 thousand years ago – human settlements begin to appear in the archeological record, and as some of these settlements grew into large urban centers within the course of a few thousand years. With their growth, social hierarchies made a comeback, but this time transformed as hierarchical institutions. Once social functions could no longer be managed and regulated informally by small bands of nomadic hunter-gatherers, social hierarchies become a necessity humans is as good example. Other examples of gene-cultural co-evolution are probably abundant but until recently have not received much attention. One of the best known is the emergence of enzymes that metabolize lactose in cow’s milk, as milk became a basic staple in pastoral and horticultural societies in Europe during the early Holocene (12,000 to 5000 BP). A recent section in Science featured articles showing that genes that effect brain development are subject to ongoing selective pressures (Balter, 2005).

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in order to regulate and control these functions. Religious institutions emerged (in part) to create communities of like-minded individuals that share common beliefs and values and that can support and help each other (Wilson, 2002). Judicial institutions emerge to create and manage a body of laws that regulate civic duties and responsibilities. Policing institutions emerge to settle conflicts, and to keep antisocial individuals from having a free reign. Military institutions became necessary to defend from aggression from other groups or states and to wage war (Dubrueil, 2010). This history is very complex and egalitarian forms of organizations continued to coexist with these emerging institutional hierarchies. At times, the ruling elites of these social hierarchies take over these institutions and became despotic, but these despotic periods of our history have never managed to completely eradicate or squash our egalitarian and fairness longings rooted in the very origin of our species.

This is not to say that institutional hierarchies are the only way social hierarchies have persisted among humans, and that ritualized dominance and submissive displays and behaviors, so dramatically noted among our ape cousins, disappeared from the human condition, far from it. Bullies of all stripes are still with us, and the results of their bullying can have devastating consequences for their victims. The most productive way humans can channel our evolutionary legacy of dominance hierarchies and competition (the ranking system) is by instilling norms of fair play, and by creating a level playing field, where people compete based on merit and competence, rather than by the use of force and intimidation. Some of these competitive individuals can become leaders and might end up having a strong influence on people they lead. Our species has always been in need of good leaders that respect norms of human dignity and fairness, and have the required competence, vision and skills. Without these leaders social institutions cannot function well and humans cannot flourish (Maccoby, 1981, 2003).

We can also observe the fate of dominant-submissive rituals and gestures (the ranking system) in clinical cases. Very little has been written about this application of evolutionary psychology to the field of mental health and psychopathology, but two pioneers stand out: the British scholars John Price (1967) and Paul Gilbert (1989, 1992, 2005a, 2005b). It is beyond the scope of this essay to summarize their contributions, an effort that would require a long article by itself. Suffice it to say that Gilbert has developed a very interesting model of the mind composed of four basic “social mentalities” that clearly overlap with some of our thinking. His model includes mentalities geared to seek protection, provide protection, cooperate and compete. We will add to this line of thinking by briefly exploring in the last two sections how the ranking system can be co-opted for defensive purpose to cope with complex, attachment-related trauma.

A hierarchy of evolved motivational systems Natural selection endowed reptiles, birds and mammals with different motivational systems capable

of regulating behavior in the direction of adaptive goals. The goal of each system, and the basic neural network and behavioral patterns needed to achieve it has remained quite similar across the evolution of different species. Some of these systems concern the relations of the individual organism with the non-social environment, and are the most ancient (the reptilian brain), while other motivational systems are involved in different aspects of the relation with members of their species (conspecifics) and are the characteristic of mammalian evolution. Still other motivational systems developed among our hominin ancestors and took the prosocial motives already present in mammals, to a whole new level of caring for others and ability to cooperate and collaborate in small large and very large projects—the neo-mammalian brain. This implication of considering the time trajectories in the evolution of the various systems was intuited by Hughlings Jackson (Farina, Ceccarelli, & Digiannantonio, 2005; 2012) and by Paul MacLean in his model of the triune brain (MacLean, 1985). According to Hughlings Jackson, the evolutionarily older systems when activated by proper environmental conditions tend to pre-empt the

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activation of the other systems. At the same time, the evolutionarily more recent systems acquire regulatory capacity over the activities of the older phylogenetic systems. Porges polyvagal theory is the latest addition to this evolutionary and hierarchical view (Porges, 2011).

The Reptilian Brain

The evolutionarily oldest, non-social systems evolved among reptiles and regulate homeostatic functions, reproduction, territoriality, exploration of the environment, predation, and defense from predators and other environmental threats. Dominance hierarchies exist in many species of reptiles and are prevalent in almost all mammals and birds.

The mammalian brain (66 million years ago)

The two main functions of dominance hierarchies in many species of mammals is to establish preferential access to sexual partners and food based on rank and to avoid contests over rank from becoming lethal through ritualized dominance displays and submissive gestures. Ritualized displays very often settle ranking contests from becoming a fight to death. The next set of motivational social systems that appeared during the evolution of vertebrates is associated with species in which parental care and attachment behaviors emerged 66 million years ago following the massive extinction of dinosaurs (a few species of dinosaurs had began to exhibit maternal care before this massive extinction). Maternal care and attachment are, of course, frequent features of mammals.

The neo-mammalian brain (beginning with the Pliocene–Pleistocene transition 1.8 to 2 million

years ago) According to Hrdy (2013) a prosocial cooperative breeding system that included at nonkin group

member (what we are calling the cooperative social engagement system) may have emerged among H. erectus 1.8 million years ago. The emergence of moral order in which shared prosocial norms and values played a leading role, emerged much later probably with Homo sapiens. Boehm (2012) assigns a date of 45,000 years ago, when behavioral and cultural modernity appears clearly in Europe, bur recent data suggest that behavioral modernity might have appeared much earlier in south Africa approximately 100,000 years ago (Balter, 2011). We agree with Hrdy that the emergence of cooperative breeding (and we believe long lasting sexual ties) might have prepared our hominin ancestors for this evolutionary innovation. It seems very likely that the emergence of an ultracooperative mutual aid system went hand in hand with the development of intersubjective communication and the ability to understand the minds of others through empathic and intersubjective abilities. In turn these developments set the stage for the emergence of language and a symbolic culture that allows cultural learning and cumulative culture to be passed on from one generation to the next.

Clinical Implications

There are significant implications of this account of human evolution, and the hierarchical multimotivational model of the human mind. These implications apply to the social sciences in general, and even more broadly to our views of human nature, but we will limit our comments to applications to the clinical dialogue. We will approach this section by breaking down the discussion into two parts. First, some basic characteristic of hierarchical multimotivational model of the mind, and second, we will expand on these points in regard to clinical treatment with patients with complex trauma where the hierarchical view of motivation becomes a very useful tool. Basic characteristics of the hierarchical multimotivational model

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1. Different motivational systems have specific triggers that activate and “deactivate” them (deactivation is better described as being in a stand-by or expectant mental state). Take the attachment system as an example. When we perceive a threat or are in a vulnerable state such as being ill, we may feel stressed, frightened or anxious, these feelings will activate a search for physical and emotional proximity to an attachment figure. Once comforted by attachment figures, the attachment system goes back to its stand-by state. There is a constant shift between different motivational systems, so that at any given time one motivational system is in the foreground and another in the background and vice versa, background becomes foreground (Lichtenberg, Lachmann, & Fosshage, 1992). Let’s say that a child is in a playground with his parents and scrapes his knee. The child will go to his mother or father (activation of the attachment system), who will comfort him (activation of the caregiving system in the parent). After being soothed, the child will immediately go back to exploring the playground or playing with other children. The exploratory system will then be activated if the child is interested in the equipment that is in the playground, or the cooperative and social engagement system will become active if the child is playing with other children.

2. Motivational systems sometimes can interact at the same hierarchical level or between different hierarchical levels. When children are playing together and learning from each other, their neomammalian brains are operating at the same level. But if these same children find they are in danger (for instance they see somebody badly hurt or shot) the neomammalian functions are temporarily suspended and they will activate the mammalian attachment system or the defense fight/flight system. Survival functions organized around attachment or the defensive fight /flight reactions will immediately suspend higher functions of the neomammalian brain’s cooperative and social engagement system. Since this social engagement system coevolved with intersubjective communication, they are functionally and dynamically related. It is not unusual to see that when the attachment system becomes highly activated, the intersubjective abilities to empathize with others or maintain a perspective on these social relations are put on hold. In extreme cases involving cumulative trauma, we can observe the collapse of these intersubjective abilities—described by Fonagy and his colleagues as mentalizing abilities (Fonagy, Gergely, Jurist, & Target, 2002), by Main (Main, 1991) as metacognitive abilities, and by self psychologists as an empathic ability to sense into the minds of others (Lichtenberg, Lachmann, & Fosshage, 2002)

3. Normally there is a harmonious back and forth between these different motivational systems. Clinically we observe that this back and forth between motivational systems can be used defensively (coopted) to cope with emotional conflicts or trauma. An example from the attachment literature will illustrate this point. The Strange Situation (SS) is a 20 minute laboratory procedure aimed at examining the balance between attachment and exploration when the attachment system is activated by a stressful event created when the attachment figure leaves their infant by themselves for a brief moment (Ainsworth, Blehar, Waters, & Wall, 1978). Securely attached infants, like all infants, are very stressed by this procedure. Yet babies with a secure history use their mothers well when their mothers return by going to them and seeking their comfort without any hesitation. In turn, these mothers are effective in comforting their infants. Once comforted these infants very quickly return to explore the attractive toys that are in the room. In contrast, infants with an insecure (avoidant) attachment history behave very differently. Having had the experience of being ignored or even rejected when distressed, in the SS these infants avoid paying attention to their mothers when they return, and instead play with the toys. In effect, they co-opt the exploratory motivation by playing with the toys in order to self-regulate their distress. This general principle is not limited to the exploratory system and can involve other motivational systems, as can be observed commonly in peoples lives and in clinical situations. The sexual mating system can be coopted to avoid the dangers of intimate relations by having shallow relations with multiple partners. The caregiving system can be coopted to avoid exposing vulnerabilities by becoming a rescuer of other vulnerable people. Bowlby (1980, pp. 156-157) described this personality type as “compulsive caregivers”. The ranking system

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(dominance hierarchies) can be coopted to cope with disorganizing fear toward an attachment figure, as we will see shortly. With this general orientation, we can explore with greater detail some clinical implications of this

hierarchical multimotivational model in the treatment of posttraumatic syndromes. An evolutionary approach to posttraumatic syndromes

A defense system that is part of the autonomic nervous system (ANS) with its sympathic and parasympathic branches evolved among vertebrates in order to respond to threats to survival with the typical sequence of autonomic, emotional and behavioral responses (fight, flight and feigned death) – a sequence whose neurological underpinnings we now understand quite well thanks to Porges’ (2011) polyvagal theory. The autonomic hyperarousal of the sympathic branch of the ANS mobilizes the organism for fight or flight. Freezing (brief phase of alert immobility with heightened muscle tone) is a demobilizing reaction and usually occurs when the animal cannot fight and falls into a hopeless state captured well by the phrase “freeze when no other type of flight is possible”. The survival value of feigned death lies in the fact that predators often avoid eating an animal that looks dead. The feigned death or freeze response is governed by the dorsal (demyelinated) part of the vagal nucleus (parasympathetic arousal). Feigned death produces flaccid immobility due to sharp reduction of the muscle tone, and extreme global autonomic hypoarousal (very low respiratory and heart rates, very low blood pressure, numbing of consciousness).

The relevance of the experience of feigned death for our understanding of posttraumatic syndromes lies in its power to explain a group of symptoms that include autonomic hypo-arousal and somatoform symptoms linked to it, numbing of consciousness and, most important for the psychotherapeutic dialogue, a deep feeling of helplessness and impotence (Shore, 2003). These feelings and their somatic concomitants linked to the priming of traumatic memories are at least as important in defining trauma-related disorders, as are the symptoms of autonomic hyper-arousal (the sympathic branch of the ANS) listed in the DSM-IV as diagnostic criteria for posttraumatic stress disorder (PTSD). Knowledge of the evolved response of feigned death and freezing provides clinicians a good understanding of the dynamics of the parasympathic (vagal) nervous system and helps clinicians avoid interpreting these vagal symptoms of severely traumatized patients as ego defenses.

When a responsive attachment figure is available during or soon after a traumatic event, it activates the parasympathic ventral (myelinated) part of the vagus nerve that supports the cooperative and social engagement system that allows children or adults to seek physical or emotional proximity (“a good vagal tone”). A good vagal tone also inhibits the fight/flight response of the sympathic branch of the ANS, or the more primitive demobilizing freeze response mediated by the dorsal branch of parasympathetic system. Cantor (2005) has convincingly argued that all PTSD symptoms are the expressions of the protracted activation of the fight, flight, freeze due to a combination of an unavailability of secure attachment figures in the aftermath of trauma, or to negative expectations associated with a history of disorganized attachment. These negative expectations prevent children and adults from making use of help and soothing from others. There is evidence that the protracted activation of the defense system hampers high-order cognitive functions associated with the development of intersubjective abilities (Liotti, 1999, 2004).

The relevance of considering the attachment system in the aftermaths of traumatic events is supported by research studies that suggest that a history of a secure attachment is carried forward as a set of positive expectations that others will be responsive and helpful (Sroufe, Egeland, Carlson, & Collins, 2005). This helps explain how positive expectations act as protective factors against the development of PTSD (Besser, Neria, & Haynes, 2009; Muller, Sicoli, Kathryn, & Lemieux, 200; O’Connor & Elklit, 2008).

Disorganized attachment and complex PTSD

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Infant attachment disorganization is observed in two main types of interaction with the caregivers: when the caregivers are straightforwardly hostile (Lyons-Ruth, Yellin, Melnick, & Atwood, 2005) and frightening to the baby (Main & Hesse, 1990), and when they abdicate their caregiving responsibilities (Solomon & Gorge, 2011) because they feel helpless (Lyons-Ruth & Jacobvitz, 1999) or frightened by unresolved traumatic memories (Main & Hesse, 1990).

While providing care, some attachment figures become abruptly aggressive and frightening to the infant. This puts infants into an irresolvable conflict, since attachment figures are also havens of safety. These caregivers become at the same time the source of the infant’s fear and the solution of the infant’s fear (Main & Hesse, 1990). In these circumstances, the attachment and the defense systems are activated simultaneously, causing a state of fright without solution (Main & Hesse, 1990). The result is an escalation of fright combined with utter helplessness. The conflicting activation of the defense and the attachment system in the infant can also be caused by caregivers who are not aggressive or maltreating, but who are unable or unwilling to respond the infant’s cry for help and soothing. This possibility is dramatically illustrated by the still face experiment (Tronick, 2007) in which babies in the first months of their life react to their mothers unresponsive face fin the span of a few seconds with fear, and then with unmistakable signs of feigned death (Tronick, Als, Adamson, Wise, & Brazelton, 1978). The reaction is indicative of dorsal demyelinated vagal activation to the caregivers’ lack of responsiveness to infants cues and communications (Schore, 2009). The experience of lack of caregivers’ response to bids for help and soothing activates by default the defense system in the infant, even in the absence of an immediate environmental threat.

Later in development signs of the activation of the defense system are evident in older infants with disorganized attachment – either due to caregivers’ frightened/helpless/abdicating attitudes or to caregivers’ hostility and explicit violence during the Strange Situation (SS) (Main & Solomon, 1986). The infant’s disorganized attachment behavior in the SS is characterized by one or more of the following: freezing in the middle of an attempted approach to the caregiver, fright-avoidance, rage and attempted attacks to the caregiver, collapsing to the ground and stilling – caused by dorsal vagal parasympathic arousal (Porges 2011) – or by abnormally exhibiting slow movements (as if the baby was moving in water). Since human infant’s extreme motor immaturity prevent then form fight or flight response when facing threats, it is not surprising that the activation of the freeze response (analogous to feigned death) is the only remaining strategy.

The knowledge of attachment disorganization provides a relational context for understanding the core dissociative disorders related to personality development that have their roots in traumatic or neglecting family environments. Herman (1992) and Gunderson and Sabo (1993) among others, suggest that these disorders should be regarded as instances of complex PTSD that may become expressed as borderline personality disorder (Meares, 2012) or as dissociative disorders (Liotti, 2004, 2006). The role played by the defense and attachment system in the genesis of attachment disorganization and pathological responses to trauma suggest that dissociation is not merely an inner defense from mental pain, it also includes a specific form of relatedness (Lyons-Ruth, 2003; Meares, 2012). Controlled longitudinal studies show that this type of relatedness originating from an early attachment disorganization predicts later dissociation more than does exposure to traumatic events (Dutra, Bianchi, Siegel, & Lyons-Ruth, 2009; Ogawa, Sroufe, Weinfield, Carlson, & Egeland, 1997).

The cooption of the ranking system in patients with histories of disorganized attachment and trauma

Dissociative symptoms and behavioral disorganization have not been observed clinically in the interactive behavior of school age children who have a history of disorganized attachment. This is probably explained by the discovery made in two samples in a low risk prospective longitudinal studies. By the age of six, these children develop strategies aimed at controlling their caregivers’ behavior either through dominant-punitive or through protective-caregiving attitudes (Main & Cassidy, 1988; Watner, Grossmann, Gremmer-Bombik, & Sues, 1984). The protective-caregiving response of

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children is an indication of an inversion of the normal direction of attachment-caregiving interactions between parent and child (Bureau, Easterbrooks, & Lyons-Ruth, 2009). The evolutionary model that we present explains the development of these controlling strategies with the hypothesis that in order to avoid shattering dissociative feelings, unbearable experience of fright without solution, and the helpless relational chaos, the ranking and the caregiving systems, are coopted for defensive purposes (Liotti, 2011). The cooption of the ranking system leads to the dominant punitive controlling strategy, while the cooption of the caregiving system leads to the protective caregiving strategy.

The relational problems that emerge from trying to regulate the dissociative experiences and controlling strategies linked to a history of disorganized attachment create formidable challenges during the clinical exchange. It is not unusual to observe during a therapeutic process that is progressing well the sudden emergence of dominant-punitive attitudes and behaviors. These sudden disruptions are difficult to understand on the basis of previous exchanges. The conflicting activation of the defense and the attachment system together with the activation of controlling strategies lies at the root of many traumatic transferences and countertransferences (Howell, 2011). The hierarchical evolutionary model that we have outlined suggests that at the beginning of treatment these difficulties with complex trauma can best be dealt with by trying to maintain a dialogue that attempts to limit the activation of the attachment system by taking advantage of the natural tendency to want to cooperate and collaborate on an equal basis levels. This natural tendency is the outcome of our species ultracooperative path toward survival. Optimally, we try to develop a secure base and a haven of safety in therapy in order to facilitate the exploration of the relational dilemmas and severe conflict brought by complex trauma and disorganized attachment. But in cases of severe trauma, this goal has to be reached through a circuitous route that tries to limit the premature activation of the attachment toward the therapist. Otherwise the transferential activation of the trauma early in therapy will create a state of panic and can triggers the fight, flight or freeze responses that are very hard to contain and almost impossible to understand at that moment.

How the cooperative and social engagement systems helps in restoring the therapeutic alliance

The highly developed cooperative/altruistic system in humans (the cooperative and social engagement system) that coevolved with intersubjective abilities is instrumental in building mutuality, trust and hope, key ingredients of the therapeutic (working) alliance and being able to repair the inevitable disruptions that will occur in therapy. The establishment of a working alliance builds on mutuality, and provides the necessary scaffolding that will allow patients with histories of traumatic attachment to build trust before they are able to expose deep wounds. Mutuality and trust are the sine qua non in the treatment of patients with histories of cumulative childhood trauma and disorganized attachment (Van der Hart, Nijenhuis, & Steele, 2006). The model of a hierarchy of evolved motivational systems helps explain the key role cooperation and intersubjective communication plays in developing the working alliance based on mutuality. A working alliance based on collaboration and mutuality, together with an empathic engagement geared to sense into the intentions feelings and mental states of patients, allows for a gradual modulation and mentalization of unbearable mental states linked to disorganized attachment and fight/flight/freezing defensive operations.

Shared goals during the therapeutic dialogue, shared attention and shared intentionality are hallmarks of the activation of the cooperative and social engagement system (Tomasello, Carpenter, Call, Behne, & Henrike, 2005). By building on the foundation of shared goals within a spirit of inquiry and mutuality, we give patients time to express attachment longings toward the therapist. Building a cooperative foundation during clinical dialogue preserves mentalization – otherwise severely hindered by the activity of the disorganized internal representations of attachment, and helps limit panicked fight flight reactions. Minimizing these disruptive episodes in the therapeutic keeps mentalization from becoming severely compromised by dysfunctional recruitment of the ranking system (controlling punitive strategies) or by the recruitment of the caregiving system (compulsive caregiving strategies).

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As disruptions become less frequent and repairs to the therapeutic alliance develop, it gives time for patients to gradually regain these vitally important perspective-taking (mentalizing or empathic) abilities.

As we mentioned earlier, other forms of defensive cooption might be recruited (coopted). For instance, the sexual system might sexualize the therapy relationship and thus protecting from true intimacy and exposing vulnerabilities. The stable activation of the cooperative and social engagement system during the clinical exchange allows therapists to explore the role and the meaning of the controlling strategies as ways for protecting the sense of self from shattering relationship experiences linked to the activation of unconscious traumatic memories. A cooperative approach that has built trust over time also helps when controlling strategies are enacted in therapy.

During the first phases of the treatment it is common that patient and analyst may feel deeply powerless in dealing with highly distressing depersonalization symptoms and ongoing trauma-related dissociative experiences that interfere with mentalization (Liotti, 2013). If the analyst consciously accepts and contains the feeling, the evolutionary model we have proposed opens the possibility that a particular type of intersubjective communication can begin to regulate the clinical exchange. The analyst fervent desire to persevere in the work in the face of many challenges is tacitly shared through the intersubjective nature of human communication. The mirror neuron system may mediate this seemingly paradoxical type of intersubjective sharing, even when it is never expressed in words by therapist or patient (Liotti, 2013). We think that this is because intersubjective communication and the closely linked cooperative and social engagement system operate at a higher level of the motivational hierarchy (the neomammalian brain), while the defense fight, flight, freeze system operate at lower mammalian brain levels. The intersubjective communication of hope and perseverance may set in motion important corrective relational experiences by offsetting symptoms of depersonalization and feelings of powerlessness linked to childhood traumatic memories. By staying with the patient during these episodes powerlessness with attentive forbearance, the analyst communicates that the traumatizing experiences of neglect and isolation with attachment figures will not be repeated. It is important to emphasize what the analyst is not doing. The analyst is not minimizing the impact of the trauma, as perhaps attachment figures may have done in the past – which is a denial of the child’s suffering and is a severe empathic failure. Isolation and mistrust gradually fade away as the persistent activation of the defense system, experienced as deep powerlessness and depersonalization diminishes. As a consequence depersonalization symptoms may slowly subside and the mentalization and empathic capacities improve (Liotti, 2013).

Conclusion We conclude this essay by sharing with our readers a few reflections. The model we have presented

is based on the work of many scientists and researchers who are challenging traditional views on the evolution of altruism and cooperation that have dominated the field in the past few decades. These view sees genes as selfish replicators that are pursuing their survival through cooperative means (Dawkins, 1976/1989), and see cooperation as a type of mutualism, such in Tit for Tat games (Axelrod, 1984; Axelrod & Hamilton, 1981; Trivers, 1971). The problem with these views is not that they are wrong; it is that they are partial, and only capture part of the remarkable story of human evolution. The emergence of prosocial motivations and emotions that are genuinely altruistic, and take pleasure and satisfaction in helping others is the other side of the story. This other side needs to be told. Otherwise we are left with skeptics that believe that any collective efforts to make progress on the huge challenges that face humankind are naïve and ignore human nature. These same skeptics believe that the problems will take care of them selves if competitive forces (markets) are left alone to do their work and enlightened self-interest prevails (the invisible hand). What this blind faith in individualism ignores is

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that markets and the invisible hand can only succeed when there is a foundation of shared prosocial values and motivations, and institutions that support fair play and regulate these markets. We have seen what unbridled markets can do to nations and to the global economy.

We are an ultracooperative species, but we are also a deeply ambivalent species. Selfish motives compete with genuinely altruistic motives, domination and control compete with a thirst for equality and fairness, and a sense of solidarity toward people who are like “us” can easily turn ugly against people we see as different, as “them”. The view that emerges from this evolutionary story is not all sweetness and light, but it does affirm that altruism, empathy, and fairness are built into the fabric of our species.

First and foremost we are psychiatrists and psychotherapists who help people who have troubles in living and try to make a difference in their lives. We believe the evolutionary narrative we have outlined and the multimotivational and hierarchical model that underpins it can be of great clinical value. Multimotivational models have not have not received the attention they deserve and we hope this essay will contribute toward their greater use.

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