Pointing Behaviors in Apes and Human Infants: A Balanced Interpretation

Juan-Carlos GomezUniversity of St. Andrews

This article presents a tentatively ‘‘balanced’’ view (i.e., midway between lean and rich interpretations) ofpointing behavior in infants and apes, based upon the notion of intentional reading of behavior without si-multaneous attribution of unobservable mental states. This can account for the complexity of infant pointingwithout attributing multilayered mindreading to infants. It can also account for ape pointing, which shares someof the complexities of infant pointing, but departs from it in other respects, notably in its range of motives and itsfocus upon the regulation of executive behavior. The article explores some explanations for these similarities anddifferences and calls for a new look at human infant communication unbiased by adult communication models.

In this article I address three issues: a tentatively‘‘balanced’’ view of pointing as an alternative to richand lean interpretations; an analysis of how thisapplies to ape and infant pointing behaviors; and adiscussion of its implications for an evolutionaryunderstanding of the origins of pointing.

Pointing is a peculiar gesture. Unlike other ges-tures, like begging with the palm up, beckoningsomeone to approach, or extending up the hands as arequest to be lifted in arms, pointing has becomestripped of information about its target of commu-nicationFonly the bare referential act of identifyinga focus of attention in the environment remains. AsTomasello, Carpenter, and Liszkowski (2007) em-phasize, this pure reference is little in itself. Theypropose that the antidote to pointing’s referentialausterity is ‘‘some serious mindreading’’ by the partsconcerned. However, naturalistic observations ofpointing behaviors by infants suggest that pointingvery rarely occurs on its own: It is usually combinedwith other gestures, facial expressions, gaze alter-nations, and vocalizations (e.g., Zinober & Martlew,1985). There is therefore the possibility that themindreading challenges of pointing are substantiallyreduced by the range of complementary informationthat usually goes with it. However, questioning arich interpretation does not mean embracing a leaninterpretation. Infants are not simply interested incontingencies of behavior. They do have a complex,to some extent mentalistic understanding of behav-ior, as the studies reviewed by Tomasello et al. (2007)

demonstrate, but their pointing does not need to bementalistic in the sense of depending upon multi-layered mindreading of unobservable mental states.

For example, take the case of pointing to absenttargets. In a rich view, this is evidence that infants aretrying to make others orient mentally, rather than be-haviorally, to targets they themselves have in mind(Tomasello et al., 2007). However, infants may justbe directing the adult’s attention to the place wheresomething interesting may happen or where some-thing interesting lies hidden. The invisibility of thehidden target is no big dealFit only requires objectpermanence, an achievement well established by theend of the first year of life (Piaget, 1937). Similarly,we do not need a rich interpretation to explain apes’ability to request absent targets (e.g., food hidden ina box). In this article I explore an alternative view,which falls midway between rich and leanFa‘‘balanced’’ interpretation of ape and infant pointing.

A Balanced Interpretation of Pointing

With lean interpretations you only code contingen-cies between observable behaviors; for example, apointing gesture and the obtention of an object or theelicitation of an expressive reaction from others. Incontrast, with rich mentalistic understanding youtranslate behaviors into unobservable mental states,and with the help of these you understand that be-havior is intentional, that is, driven by internal desiresand representations of objects; for example, youunderstand that pointing makes others know thatyou wish to obtain an object or communicate a pieceof information that they ignore. In this view, attrib-uted mental representations are the unobservablecognitive glue that links people and objects. My

r 2007 by the Society for Research in Child Development, Inc.All rights reserved. 0009-3920/2007/7803-0003

This article has been written as part of Project REFCOM, fundedby the European Commission, Framework 6th, NEST-PATHFIN-FER initiative ‘‘What it means to be human.’’

Correspondence concerning this article should be addressed toJuan-Carlos Gomez, School of Psychology, University of St. An-drews, St. Andrews, KY16 9JP, U.K. Electronic mail may be sent toJg5@st-andrews.ac.uk.

Child Development, May/June 2007, Volume 78 Number 3, Pages 729 – 734

proposal, in contrast, is that behaviors are directlyperceived as intentional, that is, as being directed tothings other than themselves in the essential senseof Brentano’s notion of intentionality (Dennett &Haugeland, 1987), but without necessarily repre-senting that they are driven by unobservable mentalstates. For example, understanding that gaze is di-rected to an object does not require attributing themental experience of seeing the objectFsuch direc-tionality is directly attributed to gaze itself. Apes andinfants (perhaps on many occasions even humanadults) simply project and anticipate an object in thereal world from the line of gaze (and concomitantfacial and vocal expressions) of others. This is notdue to a simple behaviorist learning of contingen-cies, but entails a genuinely intentional projectionfrom gaze, as attested by studies showing that bothinfants and apes search for objects hidden behindbarriers using the gaze of others as a cue (Moll &Tomasello, 2004; Tomasello, Hare, & Agnetta, 1999).

But there is more: as targets and agents need notbe simultaneously perceived in order to project tar-gets from behaviors like gaze, one can remember andpredict the intentional availability of targets for others(e.g., whether they will or not be able to find anobject hidden in their absence). The ability to calcu-late relations of ‘‘intentional availability’’ betweenagents and objects does not require a representa-tional understanding of other minds, and it allowsthings like those described by Tomasello et al. (2007)in infants: directing others’ attention to new targets,pointing to hidden targets, or reacting to pointing inaccordance with the ongoing intentional relationsthat the pointing person is engaged in (e.g., puttingrings in a basket vs. stacking them on a post). Infantsdo not need multilayered, representational inten-tionality for this.

My ‘‘balanced’’ account has another twistFthedistinction between third-person and second-personintentional relations. Gaze following, where youcode the relation of someone to an external target, isan example of using third-person intentionality; gazecontact, where you code the attention of others asdirected to yourself (or more precisely, to your ownattention), is an example of second-person inten-tionality. The combination of both (e.g., pointingwith gaze alternation) produces intentional referen-tial communication of the type commonly involvedin pointing.

The key point of discrepancy with rich accounts isthe type of mentalistic understanding underlying thereferential pointing of infants and apes. I have ar-gued elsewhere that the apparent mentalistic com-plexity of the Gricean account of communication is

implicitly captured by the combination of attentioncontact behaviorsFfor example, eye contactFwithattention-directing behaviorsFfor example, point-ingF(Gomez, 1994, 2004). The implicit complexityof shared intentionality is achieved through externalbehaviorsFnot any behaviors or simple behavioristcontingencies, but behaviors that are perceived in-tentionally or referentiallyFthat is, as being abouttargetsFby the concerned parties. All the multilay-ered, Gricean complexity implicit in this, however,remains unpacked until older children and scientistsstart using explicit representational formats to rede-scribe what they are doing with their implicitsystems (see Karmiloff-Smith, 1992, for more onrepresentational redescription).

Apes are capable of combining attention contactwith attention-directing behaviors such as reachingor pointing. My suggestion is that they do so usingthe type of intentional understanding proposedabove. Am I therefore suggesting that, in my ac-count, human infant pointing is the same as apepointing? Not at all: We have plenty of evidence that,whereas human infants are cognitively and motiva-tionally adapted for referential communication withthe pointing gesture, apes are evolutionary ‘‘new-comers’’ to this type of communication, which inthem may be the product of an exaptation rather thanan adaptation (an exaptation involves the utilizationof a structure or feature for a function other than thatfor which it evolved through natural selection, andfor which, therefore, it may be neither specificallynor optimally designed). And this is reflected in howand why apes point.

Ape Pointing: How, Why, and When

One key difference between apes and infants is thatusually apes only point to request things (food, ob-jects, actions, etc.) from others, whereas infants alsopoint to show and share attention upon thingsFadissociation that at first sight parallels that found inchildren with autism (Gomez, Sarria, & Tamarit,1993). Gomez et al. (1993) were the first to suggestthat the difference between so-called protoimpera-tives (requests) and protodeclaratives (showing)could be motivational rather than cognitive. We ar-gued that neither requests were as simple as por-trayed by behaviorist accounts, nor protoimperativesas complex as portrayed by mentalistic accounts.Both types of pointing share a common cognitivecomplexity at the level of understanding behaviorsas connected to targets through attention; they differin where the ultimate goal for pointing liesFmakingpeople do things with the targets in one case, making

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people look at and emotionally react about the targetsin the other.

Apes use their referential tools (gestures com-bined with joint attention behaviors) for requestingand directing the executive behavior of others, andeven if they shared with infants all the other cogni-tive aspects of their referential machinery, this alonecould produce important differences in their actualreferential behaviors. However, there might be moredifferences than the purely motivational.

When do Apes Point?

Apes do not commonly point with their extendedarm in the wild, except occasionally for requestingfood held by others (e.g., Goodall, 1986). It is still anopen question as to whether they could be engagingin some form of inconspicuous body pointing, asMenzel (1973) suggested that his captive chimpanzeeswere doing among themselves. What is not conten-tious is that in captivity a majority of apes sponta-neously acquire pointing behaviors similar to humanpointing, especially if they are kept in cages. Theirpointing usually lacks the extended finger versusother-fingers-folded configuration of humansFit is awhole-hand pointing (Leavens & Hopkins, 1999), butfunctionally and structurally it constitutes a goodapproximation to human pointing.

Why do Apes Point in Captivity?

Captive apes are usually confined in a cage, whichrenders them helpless to reach the many interestingobjects that lie outside their narrow confines. Thiscertainly motivates them to obtain objects by othermeans; for example, tool use. Captive gorillas andorangutans, species that rarely use tools in the wild,frequently do so in captivity. An alternative to tooluse is person useFmaking others do things for you.The traditional lean interpretation is that, under thepressure of confinement, captive apes learn to pointto desired things by blind trial and error. However, anumber of detailed studies (e.g., Leavens, Hopkins,& Thomas, 2004) show that captive chimpanzeepointing is a flexible, intentional behavior that takesinto account the attentional states of humans and iscombined with other communicative signals. Chim-panzee pointing is at least as intelligent as their tooluse is in the physical domain.

Human infants, with their prolonged immaturity,are adapted to depend and learn from adults (Bru-ner, 1972; Csibra & Gergely, 2006). Captive apes areartificially made ‘‘immature’’ and dependent upon

humans (in some casesFso-called ‘‘linguistic’’apesFthey are even compelled to learn from hu-mans). Apes may respond to these conditions byexapting some of their existing cognitive skills intoreferential forms of communication. Interestingly,dogsFa domesticated species genetically selected todepend upon humansFshow some surprising ref-erential skills, in some cases (e.g., following pointingto find hidden targets) apparently superior to thoseof chimpanzees (Miklosi & Soporoni, 2006).

How do Apes Acquire Their Pointing Gestures inCaptivity?

Unfortunately, there seem to be no studies of howpointing emerges in captive apes. One reasonablepossibility is that captive pointing develops out ofritualized reaching. In contrast to apes, caged rhesusmonkeys have been reported not to engage spon-taneously in pointing to request food (Blaschke &Ettlinger, 1987; Povinelli, Parks, & Novak, 1992).When they were explicitly trained to point, initiallythey tried to reach and grab the food, and onlyprogressively they learned to produce a schematizedreaching that somehow fitted the description of‘‘pointing.’’ For monkeys, therefore, pointing maycome less naturally than for apes, even in captivity.

An alternative possibility is that whole-handpointing emerges out of the action of receiving foodor objects spontaneously given by humans. Whenhoused in cages with bars or wide wire mesh, hu-mans spontaneously give objects, including food, tomonkeys and apes, delivered not directly to theirmouths, but to their hands. Under these conditions,pointing gestures may start as an anticipation of re-ceiving a gift.

Interestingly, a longitudinal study with uncagedhand-reared gorillas interacting directly with theirhuman caretakers (Gomez, 1991, 2004) showed that,besides developing a begging gesture with their ex-tended hand palm upward toward food or toys heldby people, when it came to requesting things thatwere not in the hands of others, the gorillas preferredthe bizarre procedure of grabbing the hand of theperson and taking it toward the desired item (e.g., atoy in a pocket) or the desired target of action (e.g., adoor latch). These contact gestures were, however,systematically accompanied by the eye contact andattention-checking behaviors traditionally associatedwith intentional communication in infants (Bates,1976). When eventually housed in cages, these go-rillas developed extended arm gestures to externaltargets. However, they still frequently used theprocedure of extending their arm to the human to

Ape and Infant Pointing 731

request his/her hand, and then moving it in thedirection of a desired target. This is an inefficienttwo-step procedure: Directly ‘‘pointing’’ with theextended arm to the target would have conveyed therequest in a single stroke (Gomez, 1992).

Actions of taking the hand of adults to target ob-jects have been reported in children with autism, andhave been highlighted as an example of failure tocommunicate (Gomez et al., 1993). There are fewsystematic analyses of this behavior in autism, butwhat little there is suggests a fundamental differencefrom the gestures observed in our gorillas. Childrenwith autism never or very rarely look at the face ofthe person, and never or very rarely call the attentionof the person when taking their hand (Phillips, Go-mez, Baron-Cohen, Laa, & Riviere, 1995). In contrast,the gorillas systematically combined their hand-taking with eye-contact behaviors and preliminarycalls of attention before executing their requests.

In typical human infants Piaget (1937) described ahand-taking or hand-pushing phase at around 8 – 9months of age; for example, when they wanted aperson to activate a toy. This behavior, however, dis-appeared soon in favor of handing the toy or pointing.In descriptions of communicative behavior between8 and 12 months in human infants, hand-taking be-haviors are not mentioned at all (e.g., Hubley &Trevarthen, 1979). However, in toddlers hand-leadingbehaviors may be an important component of theirinteractive repertoire. Toddlers take your hand to leadyou to a different room, or pull down your hand tomake you sit with them on the floor (personal ob-servations). What they rarely do, but gorillas routinelydid in addition to hand leading, is to direct the handto a target of action. Toddlers usually combine theirhand leading with pointing or other distal gestures(personal observations).

Based on the scarce evidence available, there istherefore the possibility that apes’ natural choice forreferential interactions with humans is the relativelyinefficient, but nonetheless efficacious, use of contactgestures. This may betray a natural tendency to focusupon the action, rather than the object (Gomez,2005). Still apes easily acquire distal ‘‘pointing’’ be-haviors under the physical constraints of caging.Perhaps, the best proof that such ape pointing refersto objects is when they point to lead people to objectsthey do not want for themselves: for example,pointing to the hidden keys that the human needs tounlock a box with food to be handed to the ape(Gomez & Teixidor, 1992, reported in Gomez, 2004;see also Call & Tomasello, 1994). In these cases, apesuse exactly the same pointing gesture that they useto request food. This indicates that their pointing

(whatever its ontogenetic origin) for them is not justritualized reaching or receivingFit has acquired areferential or indicative meaning to identify targetsfor others’ actions.

That human toddlers use hand-leading gestures,frequently in combination with pointing, suggeststhat human communication emerges out of theintersection of different lines of referential behavior,some of them largely shared with apes, others evo-lutionary innovations that we may find only inrudimentary versions in apes under conditions ofpressure for exaptation. From an evolutionary de-velopmental perspective exaptations like ape point-ing are potential cues to how pointing evolved inhumans.

The Evolution of Pointing: The Role of OwnAttention

Pointing is a quintessential tool for joint attentionand communication. However, Bates (1976) sug-gested that in human ontogeny it may be first usednot as a communicative gesture, but as a solitary,individual behaviorFa component of the infant’sorienting response to interesting events. Before beingrecruited for communication and joint attention atthe end of the first year of life, pointing might be atool for the infant’s own attention, maybe with thefunction of underscoring a particular object or part ofa stimulus, much as adults do when confronted withcomplex arrays of objects (Delgado, Gomez, & Sarria,in press). Alternatively, or in addition, it might havethe function of making more publicly available thefocus of the infants’ own attention, thereby allowingadults to intervene with comments and actions thatcontribute to eventually socialize their attention(in this sense private pointing might fulfill a peda-gogical function, in the sense of Csibra & Gergely,2006). In fact, Bates (1976) thought that solitarypointing to salient events might decisively contributeto ensure that the later emerging social pointing iscommunicatively relevant from the beginning. Pro-vided that infants and adults have their attentioncaptured by similar events, infants will happen topoint to things that are also interesting to adultswithout in fact taking into account the adult’s inter-ests or mental states!

From an evolutionary perspective, ‘‘own atten-tional’’ pointing could be connected to the tactileexploration of new objects with the index fingerFanaction that has been described both in human infants(from around 9 months of age; Zinober & Martlew,1985) and apes (in my personal observations, infantgorillas were already doing this at 8 months), but

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never systematically studied. One possibility is thatin human infants a variety of index finger explo-ration drifted from visual-tactile to merely visual orcontemplative, maybe under the influence of theirmotor immaturity constraints. Index finger extensionmay had been retained as part of what now is justvisual exploration either because of its communica-tive value for observing adults, or because it some-how helps with the visual exploration itself (ora combination of both). Paradoxically, this wouldimply that the quintessentially communicativegestureFpointingFhas its origins in individualbehaviors of exploration and contemplation (Werner& Kaplan, 1963). It would also imply that thepointing of captive apes and infants may emergefollowing different routesFin apes, one connectedto executive action; in humans, one related to visualexploration. This may provide a potential avenue forexplaining the evolutionary innovation of protode-clarative behaviors in human infants.

Children as Unknown Primates

One problem with interpreting infant pointing withthe ‘‘serious mindreading’’ skills of adults is thedifficulty of reliably ascertaining the infants’ ownintentions and motives, even in the carefully con-trolled experiments reported by Tomasello et al.(2007). For example, consider the following personalobservation: A 21-month-old points insistently in thedirection of his bedroom from his mother’s arms.However, when trying to take him back to the bed-room, he protests, and points again. This time hismother sees that he is actually pointing to the nearbymailbox, where freshly delivered letters are visible.She had not noticed the letters, and hence the child’spointing has been very effective in communicatingrelevant information. A standard interpretation isthat the infant is informing his mother that there areletters in the mailbox. But he could equally havebeen urging her to take the letters, or requesting to betaken to the mailbox to collect them himselfFa fa-vorite activity. This problem of interpretation issimilar to the one that arises when apes point to leadpeople to a hidden tool: Are they informing, direct-ing, or urging the human to act upon the target?

One way of trying to shed light on this issue mightbe to treat infants as an ‘‘unknown’’ primate speciesand describe their emerging communication inneutral terms, uncontaminated, so to speak, by thelanguage and theory-of-mind interpretations thatwill come later. Pilot observations for such a study inpreparation by J. C. Gomez and Klaus Zuberbuhlersuggest that pointing is usually combined with

vocalizations and other expressions, but even so it isfrequently not possible to identify exactly what aninfant wants to achieve. For example, when produc-ing gestures of protodeclarative types, infants can beexhaustingly repetitive and violate some of the keyadult rules of relevance. My suggestion is that in-fant’s referential interests and means may initially bevery different to adults’. Infants have to grow intothe adult way of reference from their own referentialsystem, with its own motives and signals. Under-standing infant communication in its own terms,rather than forcing it into adult categories may be, ifnot an alternative, a much-needed complementaryline of research that may help understand the originsof how and why humans point out things to others.

Conclusion

I have sketched a tentatively ‘‘balanced’’ approach topointing behavior in infants and apesFone basedupon the notion of intentional reading of behaviorwithout simultaneous attribution of unobservablerepresentations. This level of interpretation can ac-count for the complexity of infant pointing withoutimplying the understanding and use of multilayeredmindreading by young infants. It can also accountfor ape pointing, which shares some of the com-plexities of infant pointing, but departs from it inother respects, notably in its range of motives and itsfocus upon the regulation of executive behavior. Fi-nally, I have sketched the need to develop a new(complementary rather than alternative) perspectiveon human infant communication away from the longshadow of the linguistic and theory-of-mind com-petences that arrive later in developmentFone inwhich infants are investigated as ‘‘unknown’’ pri-mates with their own unique system of referentialcommunication worth knowing on its own.

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