JOURNAL OF THE EXPERIMENTAL ANALYSIS OF BEHAVIOR

COMPARATIVE PSYCHOLOGY RETURNS: A REVIEWOF HULSE, FOWLER, AND HONIG'S

COGNITIVE PROCESSES IN ANIMAL BEHAVIOR'

EDWARD A. WASSERMAN

THE UNIVERSITY OF IOWA

Especially remarkable seems the rarity of ef-forts to trace the evolution of the human in-tellect from that of the lower animals. SinceDarwin's discovery, the beasts of the field, thefowl of the air and the fish of the sea havebeen examined with infinite pains by hun-dreds of workers in the effort to trace ourphysical genealogy, and with consummate suc-cess; yet few and far between have been theefforts to find the origins of intellect and traceits progress up to human faculty. And none ofthem has achieved any sure success. (Thorn-dike, 1911, p. 282)

This assessment of comparative psychologyoriginally penned by E. L. Thorndike in 1901could well apply to the prevailing opinion ofexperimental animal psychologists just a fewyears ago. Yet recently, interest in comparativepsychology has grown, accompanied by an ex-panding concern with cognition in animals.There has been a notable increase in the studyof attention (Andrew, 1976; Sutherland &Mackintosh, 1971), memory (Honig & James,1971; Medin, Roberts, & Davis, 1976; Spear,1978), and concept learning (Herrnstein, Love-land, & Cable, 1976; Zentall & Hogan, 1974) innonhuman animals. Further, study of the com-munication processes of insects (Lindauer,1971), birds (Marler, 1970), and primates(Gardner & Gardner, 1975; Premack, 1976;Rumbaugh, 1977) has disclosed important par-allels to human language. Finally, both schol-arly (Griffin, 1976; Jaynes, 1976; Shafton, 1976;Stenhouse, 1973; von Cranach, 1976) and pop-ular (Sagan, 1977; Shepard, 1978) works haveappeared that have rekindled debate concern-

'Cognitive processes in animal behavior. Edited byS. H. Hulse, H. Fowler, and W. K. Honig. Hillsdale,New Jersey: Erlbaum, 1978.

Reprints may be obtained from E. A. Wasserman, De-partment of Psychology. The University of Iowa, IowaCity, Iowa 52242. Preparation of this review was sup-ported in part by grants from National Science Founda-tion (BNS 75-15905 and BNS 79-14160).

ing the Darwinian thesis of mental continuitybetween man and animals.

If all of this were not enough, then publica-tion of Cognitive Processes in Animal Behaviorshould surely signal to the behavioral sciencecommunity that a veritable renaissance of com-parative psychology has begun. This volumecontains fourteen chapters by recognized au-thorities in animal learning and behavior onsuch diverse topics as: selective attention, stim-ulus- and response-learning, short-term andspatial memory, temporal discrimination, andconcept learning. Whereas the individual pa-pers in this collection vary greatly in contentand methodology, all share the common themethat, in order to advance our understandingof behavior, it is useful to consider processesand activities, generally called cognitive, thatmay intervene between changes in the environ-ment and changes in overt behavior.Of course, the invention and exploitation of

intervening cognitive variables in the analysisof behavior is not new; such was the legacyleft by the early behaviorist E. C. Tolman tosucceeding generations of experimental andcomparative psychologists. However, resurrec-tion of the cognitive approach to the study ofanimal behavior at this particular time is dou-bly ironic: first, because of the severe attacksthat have been directed at psychological ap-proaches by workers with an ethological out-look (Hodos & Campbell, 1969; Lockhard,1971) and, second, because of the strong influ-ence that has for many years been exerted onthe laboratory study of animal behavior by re-searchers with a radical behavioristic orienta-tion (Skinner, 1977).Knowing the predilection of many psycholo-

gists to polemicize their viewpoints, it seemsworthwhile at this early stage in the rebirth ofcognitive animal psychology to put this ap-proach into both historical and analytical per-spective in order to forestall fruitless debate.

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EDWARD A. WASSERMAN

We know too little about the causes andfunctions of behavior to foreclose any ap-proach that may cast light on these importantproblems.

HISTORICAL PERSPECTIVEIf the doctrine of Evolution is true, the in-

evitable implication is that Mind can be under-stood only by observing how Mind is evolved.If creatures of the most elevated kinds havereached those highly integrated, very definite,and extremely heterogeneous organizationsthey possess, through modifications upon mod-ifications accumulated during an immeasurablepast-if the developed nervous systems of suchcreatures have gained their complex structuresand functions little by little; then, necessarily,the involved forms of consciousness which arethe correlates of these complex structures andfunctions must have arisen by degrees. (Spen-cer, 1873, pp. 291-292)

These lines from Herbert Spencer's Princi-ples of Psychology (1855) first put forth theposition that man's mental functionings mayhave arisen from those of his primordial ances-tors.2 That the mind of man may have evolvedfrom that of animals is, of course, more com-monly attributed to Charles Darwin whose in-fluence on modern experimental psychologyeclipsed that of Spencer, his contemporary andcountryman (Hilgard, 1960; Magoun, 1960).Darwin's thesis of mental continuity betweenman and animal was most clearly stated in TheDescent of Man (1871), a book that stressedquantitative rather than qualitative differencesin cognition and motivation:

The difference in mind between man and thehigher animals, great as it is, certainly is oneof degree and not of kind. We have seen thatthe senses and intuitions, the various emotionsand faculties, such as love, memory, attention,curiosity, imitation, reason, &c., of which manboasts, may be found in an incipient, or evensometimes in a well-developed condition, inthe lower animals. (1920, p. 128)

Inquiry into the mental processes of manand animals thus defined the initial interest ofcomparative psychology. The first significant

2For historical purposes, the original publicationdates are given for a number of sources even though thequoted and consulted materials may have come fromlater editions. Only the quoted and consulted sourcesare cited in the references.

contributor to this endeavor was G. J. Ro-manes. His 1,882 book, Animal Intelligence,contained many carefully selected tales or"anecdotes" describing exceptional feats of ani-mal mentality, some of them rivaling humanaccomplishments. However, there are severalshortcomings of Romanes' (and Darwin's)"anecdotal method" of studying animal intelli-gence. The tellers of such tales did not alwaysdistinguish what they observed from what theyinferred; they were not well-acquainted withthe natural behavior of the species under ob-servation nor with the past experience of theindividual animal concerned; and they oftenhad the ulterior motives of testifying to thesuperior intelligence of their beloved pets orof showing themselves to be keen observers ofnature and talented story-tellers (Thorndike,1911; Washburn, 1926). Thus, C. L. Morganurged caution in the investigation of mentalprocesses in animal behavior. Morgan's famouscanon of parsimony was set forth in An Intro-duction to Comparative Psychology (1894). Iturged investigators to refrain from gratuitousanthropomorphizing and to substitute a moreprudent approach to invoking cognitive inter-pretations of animal behavior (also see Wundt,1894, p. 350): "In no case may we interpret anaction as the outcome of the exercise of a highpsychical activity, if it can be interpreted asthe outcome of the exercise of one whichstands lower in the psychological scale (1896;p. 53)."Morgan's canon, coupled with his insistence

upon the collection of observable and reliableevidence of animal intelligence, helped tomove the psychological study of animal behav-ior from the parlor into the laboratory. Ofcourse, the cautious nature of his approachmeant that one would always err on the sideof stupidity when it came to attributing men-tal prowess to animals. This did not botherMorgan or many of his successors because itwas assumed that "an ungenerous interpreta-tion of the faculties of animals can hardly besaid to be open to .. . [grievous] practical con-sequences (1896; p. 54)." In fact, the rise of theantivivisection and animal rights movementsmay in some measure have been encouragedby the (hopefully mistaken) perception that,with anthropocentric disdain, scientists inflictall manner of tortures on their animal subjects(Holmes, 1911, pp. 7-8). A further negativeconsequence is that serious scientists may have

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been discouraged from adopting the heuristicview that man and animal do share commoncognitive capabilities.The turn of the century, of course, witnessed

the true beginnings of the scientific study ofanimal psychology. Research by J. Loeb andH. S. Jennings on the lower organisms and byI. P. Pavlov and E. L. Thorndike on highermammalian animals applied objective meth-ods to psychological processes such as associa-tion formation, discrimination, and goal-direc-tion.The work of these investigators is of particu-

lar note because they pioneered the opera-tional definition and experimental study ofintervening cognitive processes in nonhumananimals. The following behaviorally baseddefinitions of cognitive processes by Jennings(1904, 1906) gives something of the flavor ofearly operationism in experimental animalpsychology (also see Yerkes, 1905):When we say that an animal perceives some-thing, or that it shows perception of something,we base this statement on the observation thatit reacts in some way to this thing (1976, p.329).Discrimination is a term based, so far as ob-jective evidence goes, upon the observed factthat organisms react differently to differentstimuli (1976, p. 329).Choice is a term based objectively on the factthat the organism accepts or reacts positivelyto some things, while it rejects or reacts neg-atively or not at all to others (1976, p. 330).

It is generally agreed that the behavioristicmovement emerged as a major school in psy-chology with the publication of J. B. Watson's1913 paper, Psychology as the BehavioristViews It. Watson, of course, discarded thestudy of subjective mental experience throughintrospection from his behavioristic psychol-ogy. Less widely appreciated is that Watsoncontinued the campaign of his predecessors totranslate other aspects of mental activity intoobjective behavioral terms so that they mightreceive detailed experimental investigation(Boring, 1950). Watson was convinced that allmeaningful facets of mental functioning in-cluding perception, memory, imagination,judgment, reasoning, and conception wouldeventually yield to behavioral analysis:

Psychology as behavior will, after all, haveto neglect but few of the really essential prob-

lems with which psychology as an introspec-tive science now concerns itself. In all prob-ability even this residue of problems may bephrased in such a way that refined methodsin behavior (which certainly must come) willlead to their solution. (1913, p. 177)

It is, however, to E. C. Tolman that creditbelongs for formalizing the attempts of Watsonand others to objectify the study of cognition.Tolman's "intervening variable" served as thekey theoretical device in both his own expan-sive "operational behaviorism" (1932, 1936)and in the behavior theory of C. L. Hull(1943). More will be said of intervening vari-ables later. For the present historical summaryit is sufficient to note that, after some prelimi-nary use of the intervening variable (e.g., driveand reflex reserve), B. F. Skinner later at-tempted to refrain from postulating any cogni-tive or motivational events which might inter-vene between the environment and behavior(Skinner, 1977).As most readers are doubtless aware, the be-

haviorisms of Tolman, Hull, and Skinner wereassociated with a notable decline in the num-ber of animal species studied by experimentalpsychologists since the early 1900s (Beach,1950). This decline reflected in large measurea desire to base detailed theories of learning onextensive study of some "representative" or-ganism(s). Interestingly, this trend toward gen-eral process learning theory began with thework of E. L. Thorndike who also helped topioneer the comparative method in experimen-tal psychology and, in the opening quotationof this paper, bemoaned the dearth of compar-ative research on intelligence. Consider the fol-lowing comments in light of his earlier obser-vations:

Experiments have been made on fishes, rep-tiles, birds and various mammals, notably dogs,cats, mice and monkeys, to see how theylearned to do certain simple things in order toget food. All these animals manifest funda-mentally the same sort of intellectual life.Their learning is after the same general type.(Thorndike, 1911, pp. 282-283)

The overriding concern of experimental psy-chologists with general laws of behavior is bothunderstandable and commendable. However,this concentration of research on a few repre-sentative species marks a major departure fromthe original concern of experimental animal

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psychology: that of comparing the cognitivecapabilities of many animal species. The earlycomparative efforts of Hobhouse (1901),Thorndike (1911), Hunter (1913), Yerkes(1917), and Kohler (1925) did receive follow-upstudy by researchers such as Harlow (1949) andBitterman (1960). Nonetheless, comparative re-search in cognition has, until recently, beenanything but a prime concern of experimentalanimal psychologists. Further, investigation ofa few representative species carries with it theperil that the results of such study will be idio-syncratic and inapplicable to a broad range oforganisms. Research on the so-called biologicalboundaries of learning (Breland & Breland,1961; Hinde & Stevenson-Hinde, 1973; Selig-man & Hager, 1972) testifies to this concern.Why then do we see such growing interest in

the study of cognitive processes in animals atthis time? Let me offer the following explana-tory proposals. First and foremost, the hypoth-esis that man and animal share common cog-nitive capabilities is simply the single mostimportant idea of comparative psychology.Darwin's thesis will just not fade away no mat-ter how many generations of experimental psy-chologists choose to ignore it. Contrary to theclaim of Hodos and Campbell (1969), compar-ative psychology does have a theory and it isthat of evolution through natural selectionlAdmittedly, systematic study of the evolutionof intelligence has had a rocky past (Warden,1928). However, modern attempts to elucidatethis issue should fare much better than earlierendeavors. The prognosis will be further en-hanced if contemporary workers return totheir roots, to learn from the successes and fail-ures of their predecessors (see Tobach, Adler,& Adler, 1973 for a discussion of the currentstatus of comparative psychology).

Second, if nothing else, modern behaviorismhas provided comparative animal psychologistswith extremely powerful methods for investi-gating the intelligence of their animal subjects.Contingencies of reinforcement and onlinecomputer control can provide exceptionallyclear communications links between man andanimals, links that can divulge cognitive pro-cesses that were earlier thought to be inaccessi-ble and beyond the ken of the student of be-havior (for one who views the conditioningsituation as involving human-animal commu-nication see Boring, 1950, pp. 621, 627). Thispossibility was foreseen by Watson:

As our methods become better developed itwill be possible to undertake investigations ofmore and more complex forms of behavior.Problems which are now laid aside will againbecome imperative, but they can be viewed asthey arise from a new angle and in more con-crete settings. (1913, p. 175)

Thus, recognizing the potency of their analyti-cal armament, comparative psychologists arenow mounting a fresh assault on Darwin's pro-vocative thesis, with realistic hopes of morefully elucidating the mental relationships ofman and animal.

Finally, the current burst of energy directedtoward cognition in animals is partly a reac-tion to recent developments in the study ofhuman cognition. Within the field of humanlearning, something of a revolution has trans-formed the discipline over the past twentyyears (Lachman, Lachman, & Butterfield,1979). More will be said later of the basic ten-ets of modern cognitivism. Here, we shouldnote that many workers in the area of humanlearning came to view their field as one ap-proaching stagnation. This state arose, somebelieved, from researchers too readily adoptinga sterile paradigm: one that, incidentally, bor-rowed many ideas from the animal learninglaboratory (Osgood, 1953). With the drift ofcognitive psychology away from many of thetraditional problems and procedures of humanlearning, some saw research in animal behav-ior as becoming increasingly irrelevant to thenewly evolving interests of human learningand performance (e.g., Lachman et al., 1979).Training apes to use a variety of sign lan-guages was a strong response to this challenge(Gardner & Gardner, 1975; Premack, 1976;Rumbaugh, 1977; but see Terrace, 1979).Undoubtedly, teaching sign languages to

nonhuman primates was the most significantsingle event in delivering comparative psychol-ogy from an age of disinterest and disrepute.But comparative psychology had never died;interest in Darwin's thesis had merely lain fal-low until this dramatic demonstration showedthat methods were available that would enableresearchers to shed new light on the problem.Having thus returned to the issue of mental

evolution after decades of inattention, furtherconsideration of analytical perspectives incomparative cognition is in order. We nowturn to such matters.

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ANALYTICAL PERSPECTIVE

A century of work in comparative psychol-ogy provides today's investigators with a richanalytical background against which to viewanimal and human cognition. The second por-

tion of this paper attempts to highlight the is-sues that are of greatest relevance to currentresearch and theory in comparative psychol-ogy.

Inferential MethodsNow, by mind we may mean two very differ-ent things, according as we contemplate it inour own individual selves, or in other organ-

isms. For if we contemplate our own mind, we

have an immediate cognizance of a certainflow of thoughts or feelings, which are themost ultimate things, and indeed the onlythings, of which we are cognizant. But if wecontemplate mind in other . . . organisms, we

have no such immediate cognizance of thoughtsor feelings. In such cases we can only inferthe existence and the nature of thoughts andfeelings from the activities of the organismswhich appear to exhibit them.... Hence it isevident that in our study of animal intelli-gence we are wholly restricted to the objectivemethod. (Romanes, 1883, p. 1)

These lines from G. J. Romanes' Animal In-telligence pose the prime problem for compar-

ative psychology: denied access to the privatedomain of animals' minds, how are we to pro-

ceed in comparing their minds to our own?Here, Romanes was clear and emphatic. Wewould have to rely on overt actions as the "am-bassadors" of mind. True, students of compar-

ative psychology rarely consider Romanes to

be a champion of the objective method. Thereason is that Romanes had a penchant forusing objective evidence to infer the contentsof an animal's subjective experience. Thus,Romanes assumed that, "the activities of or-

ganisms other than our own, when analogousto those activities of our own which we knowto be accompanied by certain mental states,

are in them accompanied by analogous mentalstates (1883, p. 6)." Such projection of con-

scious experience onto other organisms is saidto be based upon subjective inference (Mac-kenzie, 1977).

Lest we judge the method of subjective in-ference to be the misguided creation of an un-

scientific romanticizer of animal behavior, we

should note that the acclaimed C. L. Morgan

joined Romanes in avidly seeking access to theprivate experiences of animals. Morgan's(1896) words on this account are unmistak-able:

In the systematic training of the comparativepsychologist the subjective aspect is not lessimportant than the objective aspect. (p. 50)

The only mind with which we can claim anyfirst-hand acquaintance is . . . that of whichwe are conscious within ourselves. (p. 42)

Hence introspective study must inevitably bethe basis and foundation of all comparativepsychology. (p. 37)

Man is forced to interpret the psychology ofanimals in terms of human psychology. (p. 38)The wise and cautious student never forgetsthat the interpretation of the facts in psychicalterms is based upon the inductions he hasreached through introspection. The facts areobjective phenomena; the interpretation is interms of subjective experience. (p. 47)

In further fairness to Romanes, we shouldnote that subjective inference was not the onlyanalytical method he used in comparing theminds of man and animal. He was also con-cerned with those mental capabilities or "fac-ulties" that allowed organisms to adapt to thecomplexities of their surroundings (see espe-cially his Mental Evolution in Animals, 1883,1898 and Mental Evolution in Man, 1887,1889). Romanes reasoned that there might bea psychical scale roughly paralleling the phylo-genetic scale. Placement along this scale couldbe determined by the method of objective in-ference (Mackenzie, 1977): can animals learnto perform in accordance with specific situa-tional demands deemed necessary to evidencesome "psychical faculty," such as associationformation, abstraction, or ideation? If so, thenthey must possess that mental capability.Here too, Morgan concurred with Romanes

that psychical scales could be constructed byobjective means. His own evaluations of ani-mal intelligence led him to conclude that mandiffered from animals in his powers of reason-ing; whereas animals might form associations,only man can perceive associative relationshipsas such. However, Morgan left open the possi-bility of future evidence proving him wrong:"Whether this conclusion . . . is valid or not,will have to be settled, . . . not by any numberof anecdotes, . . . but by carefully conducted

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248 EDWARD A. WASSERMAN

experimental observations, carried out as faras possible under nicely controlled conditions(1896, p. 359)." Here is the side of Morgan thatwe have come to know and to appreciate!Thus, beginning with objective observa-

tions of animal behavior, investigators mightproceed to infer the presence of mind in twovery different ways: first, reasoning by analogy,they might project onto animals those innerthoughts and feelings that they themselves ex-perience under similar circumstances-subjec-tive inference. Second, reasoning by function,they might assume the presence of certain ca-pacities or activities that permit animals toadjust to the specific circumstances of their en-vironments-objective inference.

In their own writings, Romanes and Morganfailed to indicate clearly when they were in-ferring the presence of mind by subjective orobjective means. This failure to distinguishsubjective from objective inferences of mindhas caused a great deal of debate and confu-sion in comparative psychology; it may be atthe root of many workers now treating theword "cognitive" as synonymous with "men-talistic" and altogether rejecting cognitive ap-proaches to the study of animal behavior.A possible case of such confusion may in-

volve B. F. Skinner's (1977) recent remarks con-cerning what he judged to be the inadequaciesof a cognitive animal psychology:

Clearly, a science of animal behavior must bereplaced or supplemented by a science of ani-mal feelings. It would be as extensive as thescience of behavior because there would pre-sumably be a feeling for each act. But feel-ings are harder to identify and describe thanthe behavior attributed to them, and we shouldhave abandoned an objective matter in favorof one of dubious status, accessible onlythrough necessarily defective channels of in-trospection. (p. 3)

Obviously, Skinner's attack is relevant to at-tempts to study the possible mental experi-ences of animals by subjective inference. Aswe have seen, such attempts began with thework of Romanes and Morgan and they con-tinue to this day (Griffin, 1978). However, justas obviously, Skinner's comments are of littlerelevance to work concerned with elucidatingthe processes and capabilities of animal cogni-tion as determined by objective inference.

If cognitive animal psychology is ever toemerge as a well-defined and respected area of

inquiry, then more will have to be done to sep-arate the study of animal mind in its subjectiveand objective aspects. An important step hasbeen taken here by Mackenzie (1977) who re-cently proposed the distinction between sub-jective and objective inference (also see Zuriff,1979). An additional step involves furtheringour understanding of the tenets and methodsof cognitive psychology-of animals and man.We move next to these matters.

Intervening VariablesE. C. Tolman called his cognitive.psychology

"operational behaviorism" (1936). The centralaim in doing so was to underscore that the cog-nitive constructs of his behavior system wereobjectively inferred and were capable of con-crete operational verification. Thus, the pivo-tal constructs that Tolman used in his theoriz-ing were so-called "intervening variables"-hypothesized processes that interconnected theinitiating causes of behavior, on the one hand,with the final resulting behavior, on the other.During his long and productive career, Tol-

man proposed a prodigious number of inter-vening cognitive and motivational variables(see MacCorquodale & Meehl, 1954 for furtherenumeration and discussion), of which "expec-tancy" is the most familiar. Tolman's main jus-tification for inventing intervening variableswas to help summarize the limitless combina-tions of independent variables that might haveorderly effects on behavior. Thus, much econ-omy would be gained if, for example, we couldconsolidate under the concept of expectancythe effects of the number of stimulus-rein-forcer pairings, the interstimulus interval,prior experiences with the stimulus and thereinforcer, etc.

Aside from making vast numbers of empiri-cal relationships more manageable, Tolman(1938) with tongue-in-cheek, suggested that hisown theorizing efforts with intervening vari-ables relieved his "inner tensions." Othershave, less mirthfully, testified to the merits ofintervening variables in the analysis of behav-ior.As an illustrative example, consider R. M.

Church's (1978) use of the concept of the "in-ternal clock" in his recent theory of temporalcontrol in rats, delineated in the volume nowunder review. Church's systematic experimentsled him to propose that rats have internalclocks that enable them to discriminate tem-

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poral stimuli. But is the hypothesization of an

internal clock a mere extravagance that need-lessly goes beyond the empirical facts? Not so,

says Church:

Although the concept of an internal clock isnot required to explain the results of any of theexperiments described . . . , there are threetypes of arguments in favor of the concept.

First, it is possible that there is a physiologi-cal reality to the internal clock, and that we

are most likely to find it if we know its prop-

erties. Second, there is the argument of theo-retical elegance. An intervening variable may

simplify the input-output relationships. Thatis to say, the list of input-clock and clock-output relations may be shorter than the listof input-output relations. Finally, there is thepragmatic argument. It is possible that theconcept of the internal clock will lead to thediscovery of capacities of animals that other-wise would not have been identified, and thatthe concept will guide the investigator towardthe discovery of general principles of animalcognition and behavior. (1978, p. 284)

Church's argument in terms of theoreticalelegance echoes Tolman's main justification interms of explanatory economy. His pragmaticargument emphasizes the heuristic role thatcognitive constructs may play in expandingour understanding of animal behavior, a pointmost contemporary workers make with due re-

gard for Morgan's conservative canon (Segal,1978).Church's appeal to physiological verification

of the internal clock raises new issues concern-

ing postulated mediational processes in animalbehavior. As MacCorquodale and Meehl(1948) have noted, Tolman's original concept

of the intervening variable was wholly reduc-ible to the empirical relationships that it em-

braced; outside of these relationships, the in-tervening variable had no surplus meaning or

independent status. In contradistinction, so-

called "hypothetical constructs" do make ref-erence to facts outside of the empirical rela-tionships. Most often, as in the above case ofChurch's internal clock, this additional refer-ence is to physiological processes. WhereasHull often used mediational concepts in themanner of hypothetical constructs, Tolmanstuck exclusively with intervening variables inhis theorizing. Tolman's mediational processes

were purely theoretical in character; they were

in his mind, but not necessarily in the rat's.

In originally distinguishing intervening vari-ables from hypothetical constructs. MacCor-quodale and Meehl (1948) hoped to avoidwhat they saw as inevitable confusions in theuse of mediational concepts. Again, we see thatrecent criticisms of cognitive psychology bySkinner (1977) are not so much wrong, as mis-directed:

Having moved the environment inside thehead in the form of conscious experience andbehavior in the form of intention, will, andchoice, and having stored the effects of rein-forcement as knowledge and rules, cognitivepsychologists put them all together to composean internal simulacrum of the organism, . . .not unlike the classical homunculus.... (1977,P 9)

Tolman's cognitive theorizing simply neversought access to the private contents of an ani-mal's consciousness, nor did it move the studyof behavior into the skulls of animals. So longas contemporary workers infer cognitive pro-cesses objectively and restrict their theorizingto intervening cognitive variables, comparativepsychology will be well-served and will be im-mune to the sorts of criticisms made by Skin-ner.

Contemporary Cognitive PsychologyIn what is possibly the most thorough review

to date, Lachman et al. (1979, pp. 1-129) havetraced the intellectual heritage of contempo-rary cognitive psychology and have outlinedits major tenets. The reader is referred to thissource for in-depth treatment. Our presentpurposes are much more modest: to describebriefly the main features of contemporary cog-nitive psychology and to explore the relevanceof this approach to the study of animal behav-ior.According to Lachman et al. (1979), con-

temporary cognitive psychology is dominatedby the information-processing approach to thestudy of human learning and performance. Anumber of antecedent intellectual orientationsare to be credited with contributing to the in-formation-processing approach, including be-haviorism, computer science, human and com-munications engineering, verbal learning, andlinguistics.The dominant idea of the information-pro-

cessing approach is that the activities of thehuman mind can be understood by analogy tothe modern digital computer:

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Computers take symbolic input, recode it,make decisions about the recoded input, makenew expressions from it, store some or all ofthe input, and give back symbolic output. Byanalogy, that is most of what cognitive psychol-ogy is all about. It is about how people takein information, how they recode and remem-

ber it, how they make decisions, how theytransform their internal knowledge states, andhow they translate these states into behavioraloutputs (Lachman et al., 1979, p. 99).

As Hintzman (1978) put it, the computer isa "machine that thinks." Therefore, theoriesof human thought may be derived from thelogical operations of other "thinking" ma-

chines. Furthermore, the inferred processes ofhuman cognition can be tested by computersimulation; if theories of human informationprocessing are translated into computer pro-

grams, their adequacy can be evaluated bycomparing human performance to computerperformance:

When we draw the computer analogy, it is notto parts of the brain, but to human compe-

tence and capacities of the mind. We do not

refer to the hardware from which the computeris built, or its electrical parts, but to certainof its functions. The analogy is between func-tions created by appropriate programmingand human cognitive processes (Lachman et

al., 1979, p. 109).

Thus, in a very real sense, contemporary cogni-tive psychology already is a comparative psy-

chology-between man and machine. It isfounded on objective inferences of mentalprocesses: reasoning by function from the in-telligent action of human beings and theirwondrous mechanical creations.

In this light, Skinner's earlier criticism ofcognitive psychology as constructing speciousimitations or likenesses of human thought mayhave some validity at this time. However, to

claim that the information-processing ap-

proach is doomed to failure at so early a stage

in its development is highly premature (Simon,1979).Time plays an important role in operant

psychology, since the interval separating suc-

cessive responses serves as the primary behav-ioral datum. Time plays an equally importantrole in contemporary cognitive psychology.Here, the critical unit of time is that elapsingbetween a stimulus and a response. Withinthat span-the reaction time-inferred cogni-

tive processes occur that serve as the essentialtheoretical entities of the information-process-ing approach:One of the oldest ideas in experimental psy-chology is that the time between stimulus andresponse is occupied by a train of processes orstages-some being mental operations-whichare so arranged that one process does not be-gin until the preceding one has ended. Thisstage theory implies that the reaction-time(RT) is a sum, composed of the durations ofthe stages in the series, and suggests that ifone could determine the component times thatadd together to make up the RT, one mightthen be able to answer interesting questionsabout mental operations to which they corre-spond. The study of RT should thereforeprove helpful to an understanding of the struc-ture of mental activity (Sternberg, 1969, p.421).

Posner and Rogers (1978) refer to this analysisof human reaction times into stages of infor-mation processing as "mental chronometry."How does the information-processing ap-

proach-with its heavy use of the computeranalogy and its investigation of cognition viamental chronometry-relate to comparativeanimal psychology? Certainly, the treatment ofanimal behavior from a mechanistic perspec-tive is not new. The 17th century FrenchmanRene Descartes is- customarily credited withtreating animals as automata (Fearing, 1930).Descartes denied animals souls and minds; un-like men, animals were reflex machines. In the18th century, J. 0. LaMetrie extended hiscountryman's mechanistic conception to manas well. However, while viewing men and ani-mals as machines, LaMetrie did not deny themthoughts and feelings (Fearing, 1930).In the present century, Loeb was the most

notable researcher to espouse a mechanisticconception of animal behavior. Loeb's mainexplanatory construct was the "tropism," anidea borrowed from botany and used to denotea forced movement occasioned by an externalstimulus. A classical example of the theory oftropisms concerned the movement of certaincaterpillars directly toward a light source. Doesthis movement reflect purposive goal-directionon the part of the caterpillar? No, said Loeb.It was simply an obligatory movement whichresulted from locomotor actions on each sideof the body serving to balance the amount ofphotic stimulation that activated bilaterallysymmetrical receptor organs.

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Loeb unqualifiedly accepted that animalswere physicochemical machines. Besides hisown physiological and behavioral research,Loeb drew support for this position from earlyefforts to simulate animal behavior by man-

made contrivances. Consider Loeb's discussionof what today seem crude cybernetic devices:

In the case of heliotropic reactions, the mech-anist welcomes the news that John HaysHammond, Jr. has succeeded in constructingheliotropic machines. He has invented a tor-pedo which can be directed by a searchlightlike a negatively heliotropic animal, and hehas also constructed a "heliotropic" dog whichfollows a lantern in the dark like the positivelyheliotropic caterpillar. The eyes of the "dog"are of selenium, separated from each other bya wooden board which represents the nose, andallows one eye to receive light while the otheris shaded. The electric resistance of seleniumis altered by light; and when one seleniumeye of the "dog" is shaded, while the otheris illuminated, the electric energy which moves

the wheels that take the place of the normaldog's legs, no longer flows symmetrically to thewheels on both sides, and the "dog" turns inthe direction of and follows the lantern. Herewe have a model of the heliotropic animal,whose purely mechanistic character is beyondsuspicion. (Loeb, 1915, pp. 780-781)

In a somewhat more sophisticated manner,

Tolman (1939) attempted to model the behav-ior of a rat learning a simultaneous two-choicediscrimination. Tolman did not actually con-

struct a machine to simulate his rat's behavior;instead, he simply sketched the essential prop-

erties that such a machine would require. Theresulting "schematic sowbug" was thus a con-

venient way of expressing how a number ofTolman's intervening cognitive and motiva-tional variables (e.g., sensory differentiation,motor skill, hypotheses, sensory and motorbiases, demand, and appetite) might interactto produce discriminative behavior.

Despite these early efforts, simulations ofanimal behavior and cognition have been rare

and have not kept in close touch with work inhuman information processing (Restle, 1975).Future work in comparative psychology willsurely explore the usefulness of computer mod-els of performance and cognition. A fertilefield seems to lie in comparing the intelligenceof man, animal, and machine.

It is of historical note that Tolman's (1939)invention of the schematic sowbug rested heav-

ily on his analysis of choice reaction times indiscrimination learning. These data, in con-junction with measurements of overt orientingbehavior, led him to postulate selection andcomparison processes in discrimination learn-ing. However, neither Tolman nor later work-ers in animal psychology made extensive use ofreaction time measures in constructing theoriesof cognition and performance. Future work incomparative psychology will probably seemuch more analysis through mental chro-nometry (e.g., Blough, 1979).

The Evolution of IntelligenceAs noted earlier, Romanes (1883, 1887) was

the first to propose a scale of intelligence alongwhich existing animal species might be placed.Beginning with memory (the lowest mentalfaculty), the scale progressed through associa-tion formation, reasoning, communication,tool use, reflection, and self-consciousness. Notonly did Romanes feel that this mental scalepermitted the linear ordering of living species,he also felt that the scale was a useful meansof tracing the ontogenetic development of thehuman being; as the human infant matures, itsintelligence progresses linearly along the scale(also see Wundt, 1894, p. 365). By fifteenmonths, the child had reached the same pointof mental development as the anthropoid apesand the dog. Thereafter, the maturing humaneclipses all other species in terms of intellec-tual and language abilities.The numerous psychological faculties that

Romanes identified and placed along his intel-ligence scale were distinctly different from oneanother. However, Romanes was careful tonote that the psychological faculties oftengraded into one another, thus making firmdivisions between species or ages of man some-what difficult. Of course, physical evolutionistsare commonly confronted with progressionsamenable to qualitative or quantitative divi-sion. Romanes saw mental evolution in thesame way; even though a continuous process,evolution might produce abrupt changes inbiological function. His mental scale can thusbe seen to be a unidimensional ordering,where each step in the scale is both the culmi-nation of preceding steps and the preparationfor ensuing steps.

Naturally, Romanes had little experimentalevidence at his disposal with which to comparethe intelligence of animal species. Thorndike

EDWARD A. WASSERMAN

(1911) did have available some limited evi-dence, and on that evidence he concluded, as

we saw earlier, that all animals learn in prettymuch the same way. Across species, Thorndikefound

Associations . growing in number, beingformed more quickly, lasting longer and be-coming more complex and more delicate....This growth in the number, speed of forma-tion, permanence, delicacy and complexity ofassociations possible for an animal reaches itsacme in the case of man (p. 285).

Thorndike, too, noted the parallel betweenontogeny and phylogeny. "In the evolution ofthe infant's mind to its adult condition we

have the actual transition within an individualfrom the animal to the human type of intellect(p. 288)."Thus, both Thorndike and Romanes held

that there was phylogenetic and ontogeneticdevelopment of intelligence. While both ac-

cepted a continuity of mind between man andanimal, Romanes saw more diversity in animalintelligence than did Thorndike. And Ro-manes was more attuned to the emergence ofnew mental faculties throughout phylogenesisthan was Thorndike, who spoke more aboutquantitative differences among animals thanabout qualitative differences.Perhaps these differences of emphasis re-

sulted from the broader behavioral concerns

of Romanes than Thorndike, who deliberatelylimited the kinds of intelligence he studied to

those that were easily measured within a con-

strained experimental setting. Such a conjec-ture not only permits us to understand thewritings of these two individuals, but it alsoprepares us for the fact that, after Thorndike,most work in comparative psychology was di-rected toward making quantitative, ratherthan qualitative comparisons among animalspecies under highly controlled experimentalcircumstances.

Despite the rather large amount of experi-mentation involving quantitative comparisonsamong animal species, most reviewers (e.g.,Brookshire, 1970; Warren, 1973) have con-

cluded that this research has not been produc-tive. Quite simply, performance is affected byso many other factors-variations in motiva-tion and reward or punishment, and differ-ences in sensory and motor capabilities-that

valid cross-species comparisons are virtuallyunattainable.More along the lines of Romanes than

Thorndike, M. E. Bitterman has for some yearsbeen investigating qualitative differences inlearned performance among different speciesof animals (1960, 1965a & b, 1975). Bitterman'sprimary approach has been to compare speciesaccording to their orderly responses to para-metric changes in the environment. For exam-ple, some animal species may ultimately learndiscrimination reversals faster than theylearned the original problem, whereas othersmay not. Such a dramatic difference in thefunctional relation holding between numberof discrimination reversals and trials to dis-crimination mastery suggests that qualitativelydifferent learning processes may be producingthese effects. As another example, some speciesmay exclusively select the response alternativeassociated with the highest payoff probability,whereas other species may match their choiceprobabilities to the payoff probabilities. Thesetwo patterns of choice may represent qualita-tively different decision strategies-again, aninference derived from a comparison of func-tional relations.Even comparing the functional relations of

two or more species presents interpretive haz-ards; differences in motivation and reward aswell as sensory and motor differences may con-found cross-species comparison when studyinga range of independent variable values, just aswhen only one parameter value is being stud-ied. Noting the virtually impossible task ofequating situational and biological factors inlearning problems for any two species (what iscalled control by equation), Bitterman pro-posed the idea of control by systematic varia-tion. According to this notion, any suspectedconfounding factors can be systematically var-ied in order to see if such systematic variationproduces qualitatively different results. Thus,should one species show progressive improve-ment in discrimination reversal learning andanother not, then the factors of motivationand reward could be systematically varied tosee if, under any conditions, the characteristicperformances of the two species ever changes.

Bitterman's ideas of comparing the func-tional relations of different species and con-trolling cross-species comparisons by systemati-cally varying possible confounding factors areimportant contributions to comparative psy-

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chology. As more workers explore the speciesgenerality of psychological processes, theseideas should help to improve the validity oftheir comparative conclusions.

COGNITIVE PROCESSES INANIMAL BEHAVIOR

Having reviewed some of the history of com-parative psychology as well as many of thefield's central ideas, it remains to discuss morespecifically the volume now under considera-tion. As noted in the beginning of this paper,Cognitive Processes in Animal Behavior is anedited volume comprising the contributions ofseveral noted researchers in animal psychology,many of whom have published important pa-pers here in the Journal of the ExperimentalAnalysis of Behavior. Because it is a collectionof chapters by different authors, no single theo-retical stance is put forward nor is any com-mon experimental tactic adopted. Thus, forour purposes it will be most profitable to iden-tify and to discuss the major themes that arecommon to the many chapters. These themesshould serve to convey to the reader the pres-ent state of research and theory in comparativepsychology, for the present volume excellentlyexemplifies where the field now stands.

Cognitive Animal PsychologyAs mentioned earlier, the contributors to

Cognitive Processes in Animal Behavior allbelieve that our understanding of animal (andhuman) behavior will be significantly ad-vanced by consideration of intervening cogni-tive processes. All see the first step in such acognitive analysis to be distinguishing knowl-edge and performance. Thus, how animalsrepresent and interrelate the events in theirenvironments is the primary concern of theresearcher. How that knowledge is later trans-lated into overt action is a secondary concern:these actions are, after all, merely the "ambas-sadors" of the mind.Of course, such a cognitive approach does

not commit one to ponder the innermostthoughts and feelings of pigeons, rats, rabbits,and chimpanzees. Thus, Rescorla utilizes arange of response systems in analyzing his lab-oratory rats' cognitive processes, Menzel ob-serves the behavior of groups of primates inseminatural circumstances, and Premack en-gages in two-way communication with his

chimps via plastic symbols. In all of these cases,however, animal cognition is inferred objec-tively-not subjectively.

Despite pronouncements to the contrary, thequestion-What is learned?-is very much aliveand under intensive experimental scrutiny.Judging by the contributions of Rescorla,Hearst, Bolles, Fowler, Mackintosh, and Men-zel, the answer to this question is most likely tobe an S-S association, rather than an S-R as-sociation. Response-centered theories of learn-ing thus seem to be giving way (once again) toperceptually-oriented approaches.

Several of the volume's contributors com-ment on the richness and diversity of interven-ing cognitive variables in the analysis of ani-mal behavior. The following list of terms fromthe collected chapters should graphically un-derscore this point, including as it does: rep-resentation, perception, attention, attribution,abstraction, conception, memory, rehearsal,strategy, and cognitive map. Do we need all ofthese cognitive notions? Possibly not. But theauthors of the present volume would undoubt-edly argue that, whether necessary or not, suchcognitive ideas provide a fertile source of in-vestigable hypotheses whose experimentalevaluation may tell us much about the pro-cesses of animal behavior.And, should readers think that modern

workers have failed to note Guthrie's criticismof Tolman's overly contemplative rodents,Rescorla, Hearst, Bolles, and Fowler deal ex-plicitly with the issue of response productionin animal learning. Their analyses reveal anumber of perceptual, motivational, and evo-lutionary factors that can prod knowledgeableanimals into action.

Information ProcessingA second major theme of Cognitive Processes

in Animal Behavior is a commitment to the in-formation-processing approach. The degree ofthis commitment varies from author to au-thor; yet, the language of information process-ing clearly finds its way into the lexicon of eachof the contributed chapters.

Substantive issues also disclose the authors'concern with information processing in animalbehavior. The blocking phenomenon serves asa focus of chapters by Fowler, Mackintosh,Rescorla, and Wagner. This phenomenon re-veals that temporal contiguity is not a suffi-cient condition for association formation;

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254 EDWARD A. WASSERMAN

rather, it appears that conditioning will occuronly if one event provides reliable informationabout another. The above authors describedifferent information-processing theories ofblocking as well as a host of related stimulus-control phenomena.An additional stimulus-control phenome-

non, "divided attention," occurs when toomuch information is provided for each item tobe fully processed. Although well-studied inthe human laboratory, little systematic workhas been done in the animal laboratory. Re-cent research by Riley and his students seeksto fill this gap and is fully discussed in thechapter by Riley and Roitblat.Other work in the present volume pursues

particular models of human information pro-cessing in the context of animal behavior.Thus, Wagner applies the distinction betweenshort-term and long-term memory to associa-tive conditioning and habituation. He con-cludes that these ideas are of considerable ex-planatory usefulness, as are the related notionsof expectancy and rehearsal. Hulse borrowsthe idea of formal structure from the informa-tion-processing realm and shows that this con-cept may lead to novel experimentation in thearea of patterned reinforcement. Fowler andHonig apply the idea of levels of processing tointeresting phenomena in animal learning andmemory. They propose that information pro-cessing in animals may either be quite stimu-lus-specific or more broadly related to motiva-tional or instructional factors depending onsituational demands. And Olton, Menzel, andPremack describe research that discloses theability of animals to organize and integrateinformation in a manner reminiscent of clus-tering and other free-recall phenomena inlhumans.

Finally, although not specifically derivedfrom information-processing models of humanbehavior, Church pursues a machine model oftemporal perception by comparing the behav-ior of laboratory rats with the operation ofvarious physical timepieces. He concludes thatanimals possess "internal clocks" that actuallyshare many common features with manufac-tured timing devices.

Comparative PsychologyThe last central theme of Cognitive Pro-

cesses in Animal Behavior is that the businessof comparing cognitive processes in man and

animals is one that should increasingly inter-est experimental psychologists. Hulse, Fowler,and Honig note in their Preface that, "thequestion of the limits of animal intelligence isvery old, and our work may reflect a currentrenewal of interest in comparative cognition(p. xii)." Many of the contributors to this vol-ume further note their rather free borrowingof concepts from the domain of human infor-mation processing. This seems to be an inevi-tability of researchers considering higher men-tal processes in animals as well as their viewingthe processes of relatively simpler conditioningand habituation phenomena from a cognitiveorientation. Such borrowing naturally promptscomparative questions that future researchshould answer.

Earlier, it was noted that Morgan judgedonly man to be capable of perceiving relation-ships between events, although related eventsmight well lead to animals associating them.It is of interest then that many writers in thepresent volume now consider animals to becapable of perceiving the relationship betweenreinforcers and prior stimuli or responses (Res-corla, Hearst, Bolles, Mackintosh, & Menzel);the relative duration of temporal intervals(Church); the logical relationship between thequantities of successive rewards (Hulse); andthe relationships between a number of stimu-lus attributes such as contingency, similarity,etc. (Rescorla & Premack).

Lastly, Premack most explicitly performscomparative analysis on cognition in pigeonsand chimpanzees. A review of the matching-to-sample literature leads Premack to concludethat pigeons are relatively more controlled bythe absolute properties of external stimulithan by their relative properties; the reverse istrue of chimpanzees. Premack concludes thatthese weightings permit two-way communica-tion via symbols with chimps but will preventsimilar interactions with pigeons.

CONCLUDING COMMENTSOne hundred years ago, the Darwinian rev-

olution was in full swing. Its influence on theemerging science of behavior brought to thefore the issue of mental continuity betweenman and animal. Comparative psychology hasthus been around since the very beginnings ofpsychology as an experimental science.The ensuing years of research and theory in

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comparative psychology have provided us withvaluable insights into the determinants of be-havior. Yet, some avenues of investigation andanalysis seem to have led to a decline in com-parative research by 1950 and to something ofan identity crisis by 1970 (Tobach et al., 1973).

Current signs, including publication of thevolume Cognitive Processes in Animal Behav-ior, indicate that a strong resurgence of inter-est in comparative psychology and the Darwin-ian thesis has begun. The present paper hasthus reviewed the historical and analyticalbases of comparative psychology in the hopethat today's workers will devote their energiesto building on the foundations of a venerablefield of inquiry. I see comparative psychologyemerging from its recent identity crisis as avital research area with ties both to the funda-mentals of behaviorism and to the newest de-velopments in cognitive science. And I seestrong prospects for experimentally answeringthe question, "Do man and animal share com-mon mental capabilities?" The quest is as ex-citing and challenging now as it was a centuryago.

REFERENCESAndrew, R. J. Attentional processes and animal be-

haviour. In P. P. G. Bateson & R. A. Hinde (Eds.),Growing points in ethology. Cambridge: CambridgeUniversity Press, 1976.

Beach, F. A. The snark was a boojum. American Psy-chologist, 1950, 5, 115-124.

Bitterman, M. E. Toward a comparative psychologyof learning. American Psychologist, 1960, 15, 704-712.

Bitterman, M. E. Phyletic differences in learning.American Psychologist, 1965, 20, 396-410. (a)

Bitterman, M. E. The evolution of intelligence. Sci-entific American, 1965, 212 (1), 92-100. (b)

Bitterman, M. E. The comparative analysis of learn-ing. Science, 1975, 188, 699-709.

Blough, D. S. Effects of the number and form of stim-uli on visual search in the pigeon. Journal of Ex-perimental Psychology: Animal Behavior Processes,1979, 5, 211-223.

Boring, E. G. A history of experimental psychology.New York: Appleton-Century-Crofts, 1950.

Breland, K., & Breland, M. The misbehavior of organ-isms. American Psychologist, 1961, 16, 681-684.

Brookshire, K. H. Comparative psychology of learning.In M. H. Marx (Ed.), Learning: Interactions. Lon-don: Macmillan Company, 1970.

Church, R. The internal clock. In S. H. Hulse, H.Fowler, & W. K. Honig (Eds.), Cognitive processesin animal behavior. Hillsdale, N.J.: Lawrence Erl-baum Associates, 1978.

Darwin, C. The descent of man; and selection in rela-tion to sex (2nd ed.). New York: D. Appleton andCompany, 1920. (Originally published, 1871.)

Fearing, F. Reflex action: A study in the history ofphysiological psychology. Baltimore: Williams &Wilkins, Co., 1930.

Gardner, B. T., & Gardner, R. A. Evidence for sen-tence constituents in the early utterances of childand chimpanzee. Journal of Experimental Psychol-ogy: General, 1975, 104, 244-267.

Griffin, D. FR. The question of animal awareness: Evo-lutionary continuity of mental experience. NewYork: Rockefeller University Press, 1976.

Griffin, D. R. Prospects for a cognitive ethology. TheBehavioral and Brain Sciences, 1978, 1, 527-538.

Harlow, H. F. The fos-mation of learning sets. Psycho-logical Review, 1949, 56, 51-65.

Herrnstein, R. J., Loveland, D. H., & Cable, C. Natu-ral concepts in pigeons. Journal of ExperimentalPsychology: Animal Behavior Processes, 1976, 2, 285-302.

Hilgard, E. R. Psychology after Darwin. In S. Tax(Ed.), Evolution after Darwin: The evolution of man(Vol. II). Chicago: The University of Chicago Press,1960.

Hinde, R. A., & Stevenson-Hinde, J. Constraints onlearning: Limitations and predispositions. London:Academic Press, 1973.

Hintzman, D. L. The psychology of learning and mem-ory. San Francisco: W. H. Freeman & Company, 1978.

Hobhouse, L. T. Mind in evolution. London: Macmil-lan and Co., 1901.

Hodos, W., & Campbell, C. B. G. Scala naturae: Whythere is no theory in comparative psychology. Psy-chological Review, 1969, 76, 337-350.

Holmes, S. J. The evolution of animal intelligence.New York: Henry Holt and Company, 1911.

Honig, W. K., & James, P. H. R. (Eds.) Animal mem-ory. New York: Academic Press, 1971.

Hull, C. L. Principles of behavior: An introduction tobehavior theory. New York: Appleton-Century Co.,1943.

Hunter, W. S. The delayed reaction in animals andchildren. Animal Behavior Monographs, 1913, 2,1-86.

Jaynes, J. The origin of consciousness in the break-down of the bicameral mind. Boston: HoughtonMifflin, 1976.

Jennings, H. S. Behavior of the lower organisms.Bloomington, Ind.: Indiana University Press, 1976.(Originally published, 1904, 1906.)

Kohler, W. The mentality of apes. New York: Harcourt, Brace, and Co., 1925.

Lachman, R., Lachman, J. L., & Butterfield, E. C. Cog-nitive psychology and information processing: An in-troduction. Hillsdale, N.J.: Lawrence Erlbaum As-sociates, 1979.

Lindauer, M. Communication among social bees (Rev.ed.). Cambridge: Harvard University Press, 1971.

Lockhard, R. B. Reflections on the fall of comparativepsychology: Is there a message for us all? AmericanPsychologist, 1971, 26, 168-179.

Loeb, J. Mechanistic science and metaphysical ro-mance. Yale Review, 1915, 4, 766-785.

MacCorquodale, K., & Meehl, P. E. On a distinctionbetween hypothetical constructs and interveningvariables. Psychological Review, 1948, 55, 95-107.

MacCorquodale, K., & Meehl, P. E. Edward C. Tol-man. In W. K. Estes, S. Koch, K. MacCorquodale.

256 EDWARD A. WASSERMAN

P. E. Meehli, C. G. Mueller, Jr., W. N. Schoenfeld, &W. S. Verplanck (Eds.), Modern learning theory: Acritical analysis of five examples. New York: Apple-ton-Century-Crofts, 1954.

Mackenzie, B. D. Behaviourism and the limits of scien-tific method. Atlantic Highlands, N.J.: HumanitiesPress, 1977.

Magoun, H. W. Evolutionary concepts of brain func-tion following Darwin and Spencer. In S. Tax (Ed.),Evolution after Darwin: The evoluttion of man (V'ol.II). Chicago: The University of Chicago Press, 1960.

Marler, P. Birdsong and speech development: Couldthere he parallels? American Scientist, 1970, 58, 669-673.

Medin, D. L., Roberts, W. A., & Davis, R. T. Processesof animal memory. Hillsdale, N.J.: Lawrence Erl-baum Associates, 1976.

Morgan, C. L. An introduction to comparative psy-chology. London: Walter Scott, Limited, 1896. (Orig-inally published, 1894.)

Osgood, C. E. Method and thleory in experimental psy-chology. New York: Oxford University Press, 1953.

Posner, M. I., & Rogers, M. G. K. Chronometric anal-ysis of abstraction and recognition. In W. K. Estes(Ed.), Handbook of learning and cognitive processes(Vol. 5: Humiian information processing). Hillsdale,N.J.: Lawrence Erlbauni Associates, 1978.

Premack, D. Intelligence in ape and man. Hillsdale,N.J.: Lawrence Erlbaum Associates, 1976.

Restle, F. Learning: Animal behavior and hunman cog-nition. New York: McGraw-Hill, 1975.

Romanes, G. J. Animal intelligence. Newv York: D. Ap-pleton and Co., 1883. (Originally published, 1882.)

Romanes, G. J. Mental evolution in man: Origin o0human faculty. New York: D. Appletoni and Co.,1889. (Originally published, 1887.)

Ronianes, G. J. Mental evolution in animals. NewYork: D. Appleton and Co., 1898. (Originally pub-lished, 1883.)

Rumbaugh, D. M. Language behavior of apes. In A.M. Schrier (Ed.), Behavioral primatology: Advancesin research and theory (Vol. I). Hillsdale, N.J.: Law-rence Erlbaum Associates, 1977.

Sagan, C. The dragons of Eden: Speculations on thleevolution of humian intelligence. New York: Ran-dom House, 1977.

Segal, E. F. Where behavioral psychology and cogni-tive psychology meet. Revista Mexicana de Analisisde la Conducta (Mexican Journal of Behavior Anal-ysis), 1978, 4, 203-216.

Seligman, M. E. P., & Hager, J. L. (Comp.) Biologicalboundaries of learning. New York: Appleton-Cen-tury-Crofts, 1972.

Shafton, A. Conditions of awareness. Portland, Oreg.:Riverstone Press, 1976.

Shepard, P. Thinking animals. New York: VikingPress, 1978.

Simoni, H. A. Information processing models of cog-nition. In M. R. Rosenzweig & L. W. Porter (Eds.),Annual Review of Psychology (Vol. 30). Palo Alto,Calif.: Annual Reviews, Inc., 1979.

Skinner, B. F. Why I am not a cognitive psychologist.Behaviorism, 1977, 5, 1-10.

Spear, N. E. The processing of memories: Forgettingand retention. Hillsdale, N.J.: Lawrence ErlbaumAssociates, 1978.

Spencer, H. The principles of psychology. New York:D. Appleton and Co., 1873. (Originally published,1855.)

Stenhouse, D. The evolution of intelligence: A generaltheory and some of its implications. London: GeorgeAllen and Unwin, Ltd., 1973.

Sternberg, S. Memory-scanning: Mental processes re-vealed by reaction-time experiments. American Sci-entist, 1969, 57, 421-457.

Sutherland, N. S., & Mackintosh, N. J. Mechanisms ofanimal discrimination learning. New York: Aca-demic Press, 1971.

Terrace, H. S. Is problem-solving language?: A reviewof Premack's Intelligence in Apes and Man. Journalof the Experimnental Analysis of Behavior, 1979, 31,161-175.

Thorndike, E. L. Animal intelligence. New York: Mac-millan Co., 1911.

Tobach, E., Adler, H. E., & Adler, L. L. Comparativepsychology at issue. Annals of the New York Acad-emy of Sciences, 1973, 223, pp. 1-197.

Tolman, E. C. Purposive behavior in animals andman. New York: The Century Co., 1932.

Tolman, E. C. Operational behaviorism and currenttrends in psychology. Paper given at Proceedings ofthe Twenty-fifth Anniversary Celebration of the In-auguration of Graduate Studies at the University ofSouthern California, 1936. (Reprinted in Tolman,E. C. Behavior and psychological man: Essays in mo-tivation and learning. Berkeley & Los Angeles: Uni-versity of California Press, 1966.)

Tolman, E. C. The determiners of behavior at achoice point. Psychological Review, January, 1938.(Reprinted in Tolman, E. C. Behavior and psycho-logical man: Essays in motivation and learning.Berkeley & Los Angeles: University of CaliforniaPress, 1966.)

Tolman, E. C. Prediction of vicarious trial and errorby means of the schematic sowbug. PsychologicalReview, July, 1939. (Reprinted in Tolman, E. C. Be-havior and psychological man: Essays in motivationand learning. Berkeley & Los Angeles: University ofCalifornia Press, 1966.)

von Cranach, M. Methods of inference fromii anitmtal tohuman behaviour. Paris: Mouton and Co., 1976.

Warden, C. J. The development of modern compara-tive psychology. The Quarterly Review of Biology,1928, 4, 486-522.

Warren, J. M. Learning in vertebrates. In D. A. Dews-bury & D. A. Rethlingshafer (Eds.), Comparativepsychology: A modern survey. New York: McGraw-Hill, 1973.

Washburn, M. F. The animal mind. New York: Mac-millan Co., 1926.

Watson J. B. Psychology as the behaviorist views it.Psychological Review, 1913, 20, 158-177.

Wundt, W. Lectures on human and animal psychology(2nd ed.). (J. E. Creighton & E. B. Titchener, Eds.and Trans.) London: Swan Sonnenschein and Co.,1894.

Yerkes, R. M. Animal psychology and criteria of thepsychic. The Journal of Philosophy Psychology andScientific Methods, 1905, 2, 141-149.

Yerkes, R. M. Methods of exhibiting reactive tenden-cies characteristic of ontogenetic and phylogeneticstages. Journal of Animal Behavior, 1917, 7, 11-28.

BOOK REVIEW 257

Zentall, T., & Hogan, D. Abstract concept learning inthe pigeon. Journal of Experimental Psychology,1974, 102, 393-398.

Zuriff, G. E. The demise of behaviorism-exaggeratedrumor?: A review of Mackenzie's Behaviourism and

the limits of scientific method. Journal of the Exper-imental Analysis of Behavior, 1979, 32, 129-136.

Received July 7, 1980Final acceptance October 8. 1980