some important figures in primate issues and research

(see notes "Who's who")


(See reading "What accounts for our fascination..?" Early writers used animals as models for evaluating human behavior;)

early scientist-philosophers (1640-1740)

Rene Descartes (1596-1650)

Four hundred years ago, Descartes articulated a materialist view of animals and to a certain extent of humans that underlies much of modern science -- organisms can be understood as complex machines whose behavior is governed by both the environment and the nature of the "machine."

Humans, he observed, had consciousness and reason --both reflected in their language -- that seemed to have no obvious analogy in machines -- at least the machines of the seventeenth century.

Descartes set the stage for contemporary primate studies and the importance of language as distinguishing feature of homo Sapiens. See his letter to the Marquess of Newcastle in readings.

Descartes on human language

For it is a very remarkable thing that there are no men, not even the insane, so dull and stupid that they cannot put words together in a manner to convey their thoughts. On the contrary, there is no other animal however perfect and fortunately situated it may be, that can do the same. And this is not because they lack the organs, for we see that magpies and parrots can pronounce words as well as we can, and nevertheless cannot speak as we do, that is, in showing that they think what they are saying. On the other hand, even those men born deaf and dumb, lacking the organs which others make use of in speaking, and at least as badly off as the animals in this respect, usually invent for themselves some signs by which they make themselves understood. And this proves not merely animals have less reason than men but that they have none at all, for we see that very little is needed to talk (Descartes, 1637/1960, p. 42).

********end of letter*******

To some today, e.g. Rumbaugh et al, 1996), Descartes perception of non-human animals as unthinking machines seems not only false, but perhaps even detrimental to a proper understanding of their place in nature. On the other hand, keep in mind Descartes lived 400 years ago and said much the same thing about most --but not all -- of human behavior. And moreover, his mechanistic view of life has proven very successful in many ways, inspiring generations of neuroscientists including Sherrington (below.) who discovery of the reflex embodied Cartesian materialism. Descartes' conclusions about animals and language, while challenged by Alex the Parrot still have considerable merit.

And, in regard to humans but not animals having a Cartesian 'soul' . this seems due to the fact that Descartes recognized the potential infinity of human reason as reflected in human language but did not understand how a finite machine could produce an unlimited variety of behaviors. This remains a problem but at least we today have recourse to the idea of recursive functions.

Julian LaMettrie (1709-1751)

La Mettrie was a rather notorious character, who criticized Descartes for not going far enough -- humans as well as animals were just machines.

His 1742 work, L'homme machine, articulated the notion that activities Descartes attributed to the "soul" are only distinguished from involuntary and instinctual activities by the relative complexity of their mechanical processes. Humans were just very complex, highly organized mechanical "organisms."


LaMettrie also provoked Descartes by arguing that there were very few, if any significant differences between humans and animals. He did this by collecting anecdotes about animal behavior from many species and comparing the collection with the behavior of humans. Naturally Descartes did not go for this bogus argument. Moreover, Descartes pointed out that the perfection of many of the animal behaviors argued against their being evidence of reason rather than for it.

Tyson (1651-1708)

Edward Tyson was a very highly regarded physician and student of anatomy. He wrote many important descriptive pieces on anatomy including one of a porpoise (dolphin) and another in 1699 entitled "Orang-Outang or the Anatomy of a Pygmie." This was the first and remains one of the best complete descriptions of an anthropoid ape.

Tyson noted how close this creature was to humans -- even more so than to the monkeys he knew of. Of course we know today that this similarity was greatly enhanced by the age of his specimen.


Tyson's Pygmie, one of many excellent drawings by William Cowper (1666-1709).

early evolutionists and biologists (1800-1900)

Linnaeus (Carl von Linne' 1707-1778)

This Swedish naturalist published a number of editions of his "System of Nature" in which all organisms known to him were classified by their physical characteristics. Probably unaware of Tyson's work, Linnaeus still noted how remarkable little difference there was between the stupidest ape and the wisest man.

Not surprisingly, Linnaeus attributed the remarkable patterns of life he observed to "divine wisdom." (Greene, 1959)

Buffon (1707-1788)

In opposition to Linnaeus and others, Buffon saw nature in a much more dynamic fashion. He observed the plan for living bodies was far more similar than external features might indicate: "This plan proceeds uniformly from man to the ape, from the ape to the quadrapeds, from quadrapeds to…birds, fishes .. reptiles ..degenerating …to insects…plants. The principle features are nutrition, growth, reproduction…Greene, 1959; 141)

Buffon noted how man could alter nature in domestication or "artificial selection" and wrote extensively on the mutability of species.

Lamarck (1744-1829) and others (See Greene, 1959)

Lamarck, the noted French naturalist, was one of the founders of evolutionary biology. He suggested that species were not fixed and that humans may have arisen from ape-like creatures in his Philosophie zoologique (1809). This book shows perhaps the first representation of evolution as a tree. He disregarded Cartesian dualism, and considered psychology a branch of zoology. He postulated several factors in changing organs -- use and disuse, an organism's "felt need, stirring their inner consciousness", and the inheritance of acquired traits.

Unfortunately today he is most remembered for the erroneous idea --Lamarckism-- that acquired traits may be passed on to one's offspring and unused ones lost. While it was clear to Lamarck that there were transformations of species over generations, he had little understanding of how this occurred.

However the "the inheritance of acquired traits" was widely accepted by everyone in the 19th century including Darwin. Even up into the early 20th century such significant psychologists as Piaget, Watson, and Freud -- who were perhaps reluctant to give up Lamarck's optomistic view of progressive change -- entertained similar beliefs. In the USA and new Soviet Union, disproof of Lamarckism fueled a rabid environmentalism/Behaviorism.

Darwin, Erasmus (1731-1802)

A remarkable person, Erasmus was Charles Darwin's grandfather. He wrote extensively on evolution and believed that all living forms may have arisen from a original "filament." (I do not know to what extent his ideas impacted those of his grandson. JL)

Darwin (1809-1882) and Wallace (1823-1913)

Charles Darwin

From his interests in natural history and his travels around the world on the H. M. Beagle, Darwin began a lifetime of research into the mechanisms of evolution. By about 1842 he had developed many of his basic ideas about gradual evolution due to variation and natural selection. These were published in 1859 in his Origin of Species by Means of Natural Selection and more fully developed in regard to humans in his 1871, The Descent of Man. His tree representing human evolution among other primates is remarkably accurate.

Alfred Russell Wallace

In 1858 A. R. Wallace sent a manuscript to Charles Darwin that expressed a nearly exact summary of Darwin's own as yet unpublished views. (Wallace had previous correspondence with Darwin but did not know about Darwin's understanding of evolution.) On the advice of the eminent English scientists Charles Lyell and J.D. Hooker, Darwin agreed to publish two extracts from his own work in progress, along with Wallace's paper.

Wallace's paper, "On the tendency of varieties to depart indefinitely from the original type", ends:

"We believe we have now shown that there is a tendency in nature to the continued progression of certain classes of _varieties_ further and further from the original type -- a progression to which there appears no reason to assign any definite limits -- and that the same principle which produces this result in a state of nature will also explain why domestic varieties have a tendency to revert to the original type. This progression, by minute steps, in various directions, but always checked and balanced by the necessary conditions, subject to which alone existence can be preserved, may, it is believed, be followed out so as to agree with all the phenomena presented by organized beings, their extinction and succession in past ages, and all the extraordinary modifications of form, instinct, and habits which they exhibit."

Francis Galton (1822-1911)

others (Huxley, Owen, especially Weismann)

Weismann (1834-1914) was a German biologist who about 1885 discovered that reproductive cells, eggs and sperm were unique in that they were produced without any interesting connection to the experiences of their bearers. All of a womans's egg cells for example are formed in the first year of life. Sperm cells are reproduced daily in males, isolated from other cells. This meant that Lamarckism -- the belief offspring could inherit acquired traits of their parents -- was almost certainly false. Many educated in the late 19th century including Darwin, Freud, J. B. Watson, and maybe Piaget accepted some version of Lamarckism -- or at least hoped that it were true! Important exceptions at the time were J. M. Baldwin and Lloyd Morgan.

The delay in accepting Weismann's conclusions stemmed in part from the pessimistic view of progress in human nature this conception of heredity offered in contrast to Lamarckism's progressive promise. One consequence was to drive psychologists to deny heredity's contributions to behavior and emphasizing environment, leading to Behaviorism in the US and Marxist psychology in the USSR. (Note that in Lamarckism the environment quickly finds its way into heredity --much more quickly than just variation and selection might do -- if at all.)

James Mark Baldwin (1861-1934)

Baldwin plays several parts in primate history. He was an early opponent of Lamarckism when almost everyone accepted it as necessary including Darwin, Freud, and possibly Watson and Piaget. Instead he proposed "organic selection" which has come to be known as the "Baldwin effect." Rather than acquired habits becoming instinctive by some mystical process, those having a genetic advantage in acquiring an adaptive skill, would have their genes increase in the population via the usual process of natural selection. In the example of language (Limber, 1982), those with the particular genetic constitution to acquire language quickly, came to dominate the population as early acquisition greatly enhanced fitness. While is functionally equivalent to Lamarckism in that cultural "habits" can become part of the genotype, no special or unknown conditions are involved.

Baldwin's other role is laying the groundwork for many of Jean Piaget's ideas. For example the idea of stages of development driven by accommodation is an essential part of Baldwin's own developmental theory. Outcast from his professorship at Johns Hopkins University because of a scandal, Baldwin spent most of his years after a 1908 in France. (The expelled Baldwin seems to have been in good company; C. S. Peirce and J. B. Watson also lost jobs at Hopkins around this time for immoral activies.)

primate studies

in zoos and the circus (early 1900s)

Zoos and Susie

Zoos provided the first opportunity to study non-human primates. Darwin (1871) reports observations about apes made at the "Zoological Gardens. " While in the United States, the New York Zoological Park had a number of these animals on display in the early 1900s -- among them Susie, who was captured in the French Congo by Richard L. Garner. (Garner himself made some interesting observations on chimpanzees in their natural habit where he built a "cage" and lived in it for a while! He is probably the first to use Edison's then new recording device in the study of primate "language" including playback experiments at the above zoo and elsewhere.)

Gladden, G. (1914). A chimpanzee's vocabulary. Outlook, 106, (February 7, 1914), 307-310.

(insert photo and notes, Garner (19xx) here)

L. Witmer and others

Witmer (1867-1956) was among the founders of clinical child psychology in the United States. In the early 1900s, he conducted a clinical evaluation of the famous "Peter" a performing chimp. Witmer (1909) concluded other than language, Peter was much like a human!

experimental studies of biology and behavior

Thorndike, Edward (1874-1949)

Thorndike's (1898) highly original dissertation on trial and error learning and his 1911 book "Animal Intelligence" laid the foundation of much of later research into animal and human behavior. The ideas remain important today.

From Thorndike (1901) "What more of a nervous mechanism do you need to parallel the behavior of the year-old child?" p.56 seems to me highly probable that the so-called higher intellectual processes of human beings are but secondary results of the general function of having free ideas and that this general function is the result of the formation after the fashion of the animals of a great number of associations...The typical process of association described the experimental study has since been found to exist among reptiles (by Mr. R. M. Yerkes) and among fishes (by myself). It seems that not much more characterizes the primates.....this process [association] is the most comprehensive and important thing in mental life....When this is done [focus in associations]we shall not only relieve human mentality from its isolation and see its real relationships with other forms; we may also come to know more about it, may even elevate our psychologies to the explanatory level and connect mental processes with nervous activities without arousing a sneer from the logician or a grin from the neurologist." p.57

Hobhouse, L (1864-1929)

Hobhouse, L. T. (1901/1926). MInd in evolution. (the 3rd ed is 1926 ed.). London: Macmillan and Co.

Hobhouse was one of the many to criticize Thorndike's conclusions. He went on to do some experimental work of doubtful quality using a chimp and monkey, along with other zoo animals including an elephant, Lily.

Sherrington (1857-1952)

This famous British physiologist, discoverer of the reflex arc and Nobel prize winner for his work with Adrian on neuronal function, did the first mapping of the primate sensory and motor cortex using a gorilla. See Leyton and Sherrington (1917). Later Wilder Penfield did the same on humans undergoing brain surgery -mapping out the human sensor-motor "homunculus" illustrated in many textbooks.

Yerkes (1876-1956)

Robert M. Yerkes recognized early on the importance of studying and conserving the apes. He was responsible for establishing the Yerkes Primate laboratory and encouraged much of the early research into the behavior of the great apes-- in many cases supplying the animals for research projects. He and his wife Ada W. Yerkes published many papers on apes and chimpanzees.

Yerkes had a summer home in Franklin NH where he let his two chimps, Chim and Panzee, live on their own-- though they did not survive very long.

(See notes)

Wolfgang Kohler (1887-1967)

This famous German-- and after 1935 American--psychologist was a founder of Gestalt psychology. From 1912 to 1920, he served as director of the Tenerife anthropoid ape station. Funded by the Prussian Academy of Science for the study of physiological and particularly psychological animal behavior, Kohler's research led to his Mentality of Apes (1925), in which he described the capabilities of Sultan and other apes.

Kohler introduced the notion of "insight" in psychology as a contrast to "trial and error" in regard to problem solving. The controversy, originally between Thorndike and Kohler remains alive today although it seems clear that insight does not arise without an extensive period of experience, probably involving much trial and error learning. (And even then, as Kohler would agree, insight is very limited in non-human primates.)

Kohts, Nadia (1889-1963)

Nadia Ladygin-Kohts was the wife of Alekssandr Kohts, curator of the Zoological Laboratory of the Darwinian Museum in Moscow in the 1920s. She was "directress of the laboratory and lecturer of comparative psychology at the state university in Moscow. (Hahn, 1988, p.175)" She wrote several papers including "animal behavior and visual discrimination in young chimpanzees" experimentally demonstrating for the first time color vision in chimps using matching colored cloth swatches. She kept a young chimpanzee, Joni, in her home for several years until it died at age five. Later she wrote a comparative study of Joni and her son. She had extensive correspondence with Yerkes and he visited her lab in Moscow in 1929.

Kohts also found her chimp could match shapes and size. Moreover, Kohts reports the chiimp could also match an object unseen in a bag to a visual sample - a matching across modalities generally thought quite difficult if not impossible for non-human primates.

Kohts, N. (1928). Researches sur l'intelligence du chimpanze par la methode de 'choix d'apres modele'. Journal de Psychologie Normale et Pathologique, 25, 245-275.

Kohts, N. (1935). Infant ape and human child. Scientific Memoirs of the Darwin Museum, 3, 524-591.

Ladygina-Kots, N. N., & Demovskii, Y. N. (1969). The psychology of primates. In M. Cole & I. Maltzman (Eds.), A handbookof contemporary Soviet psychology (pp. 41-70). New York: Basic Books.

Ladygina-Kohts, N. N. (1935/2002). Infant chimpanzee and human child (B. Vekker, Trans.). New York: Oxford University Press. (new publication of the 1935 paper).


early experimentalists: Thorndike, and others

Edward L. Thorndike, (1874-1949) was one of the first psychologists to experimentally study learning. He more or less developed the concepts of "trial and error" learning, arguing this was the fundamental means by which all organisms learned. In his "Law of Effect," satisfying or positive responses tended to be repeated while irrelevant or negative ones were not. Noted mostly for his work with cats in his "escape box", Thorndike also did work with monkeys and concluded there were no basic differences among species in learning processes -- a point disputed by Kohler but still reverberating today.

Another of Thorndike's initial objectives was to see if animals -- like humans -- could learn effectively by imitation. He could not demonstrate any such learning in his experiments though many have claimed otherwise. The issue is still debated as "imitation" turns out to be a complex matter.

Hamilton, Haggerty, and Carpenter

(H&H were students of Yerkes and Carpenter's research was supported by him.)

Harlow (1905-1981)

Although Harry Harlow studied monkeys, he made extremely important contributions to our understanding of primate behavior in several areas: intelligence and learning, "mother love", and the effects of early experiences on later social, sexual, and cognitive behavior.

Several of his methodological innovations are widely used including the concept of "learning set," the Wisconsin General Testing Apparatus (WGTA), and the "strange situation" for measuring the attachment of young primates to their mothers.

His findings on the importance of early experiences has led to the widespread recognition today that primates in captivity have psychological needs as well as basic biological ones if they are to become anything at all like the animals in their natural habitat.

Piaget, Jean (1886-1980)

The famous Swiss developmentalist called his theory one of "genetic epistemology" (TGE). In the terms of the times, genetic meant development and epistemology meant knowledge -- not DNA stuff -- hence a theory about the growth of knowledge. Trained initially as a biologist with a doctorate on the adaptation of molluscs to diverse environments, Piaget became famous with his studies on child development. Initially working in Binet's lab, 1919-20 and noticing how different children's minds were from adult minds, Piaget went on to make a number of discoveries regarding object permanence, conservation, and formal operations. Some of his work, related to consciousness remains unknown or misunderstood by many psychologists. He devised a complex stage theory of development drawing on the theories of Darwin and James M. Baldwin that has been used as a framework for looking at all primate development. (See Tomasello and Call, 1997 and Gomez, 2004.)

Current developmental research methods have raised questions about some of his conclusions and his work on language acquisition is certainly obsolete. However his overall theory is a useful yardstick as it attempts to integrate several different aspects of behavior developmentally.

Vygotsky, Lev (1896-1934)

Vygotsky was a Russian contemporary of Piaget; he took the ideas of Piaget and Kohler and integrated them into a Marxist developmental theory in which humans transcended their cousin apes because of language and culture. Vygotsky's interests include consciousness as a social phenomenon and many ideas on education. His work was largely unknown in the USA until the 1950s. We are essentially apes with language -- and language is very important.

field studies of behavior ()

Garner, Carpenter and perhaps others beginning around 1900 sought a understanding of primates in their own habitats.

Carpenter, C. R. (1940). A field study of the behavior and social relations of the gibbon (Hylobates lar). Comparative Psychology Monographs, 16(5), 1-212. (Reprinted in Carpenter, C. R. (1964) Naturalistic behavior of nonhuman primates. University Park: Pennsylvania State University Press.

Japanese primatologists

After the war, Professor Imanishi and colleagues began a study of native Japanese monkeys. The famous Imo and evidence of cultural traditions was a product of that research. Since then Japanese researchers were among the first to study chimps and bonobos in their native Africa.

Itani, J. (1985). "The evolution of primate social structures." Man 20(4): 593-611.

Leakey's curious protege's

Goodall, Fossey, Galdikas-- (see videos)

Schaller and others

home raised apes (1920-1950)

Kohts (1889-1963)

See above.

the Kellogs'

These brave psychologists sought to answer the old question of how much role environment played in primate behavor by raising Gua, a chimp infant, along with their son, Donald for a period of nine months. Gua was 7/5 months old when the project began in June, 1931. Donald was two months older than Gua. (See video notes.) The Kellogg's (1933) book reflects how reports of feral children, Witmer's account of Peter, and behaviorism led them to their endeavor.

The Kellogg's tested both young primates on various experimental tasks and the Gesell preschool readiness tests. At the earliest testing, both were very similar, but Donald pulled ahead over the next few months.

Gua displayed considerable non-verbal communication of intent and needs, as well as a certain degree of comprehension of English, but she never developed any articulate speech. Without a doubt, this project --like that of Kohts'-- verified the instinctive nature of human language. (Probably to the disappointment of the Kellogg's.)

the Hayes'

These psychologists raised Vicki from a neonate until she died at age 7. Unlike Gua, Vicki had no human child companion. Again we see an intelligent animal, developing in a human culture, becoming in many ways human-like except in articulate language. In seven years, Vicki marginally articulated several "words." See Hayes (1951) and Hayes and Nissen (1971).

Donald Hebb (1904-1985)

Hebb is widely recognized as one of the more important theorists on modeling the functions of the nervious system. His book, The Organization of Behavior (1949) remains a classic and has inspired lots of recent math models of learning. Less known are some of his other interests in primates. Working at the Yerkes Laboratory of Primate Biology, he studied chimpanzee emotions and wrote some very sensible stuff on anthropormorphism.

Hebb, D. O. (1947) Spontaneous Neurosis in Chimpanzees: Theoretical Relations with Clinical and Experimental Phenomena. Psychosomatic Medicine. 9, 3-19. With commentary by O.H. Mowrer himself.

Hebb, D. O. (1946). Emotion in man and animal: An analysis of the intuitive processes of recognition. Psychological Review, 53, 88-106.. | ISI |

Hebb, D. O. (1946) On the nature of fear. Psychol. Rev. 53, 259-276. | ISI |

(Hebb also wrote on dolphin behavior. McBride, A. F. & Hebb, D. O. (1948) Behavior of the captive bottle-nose dolphin, Tursiops truncatus. J. Comp. Physiol. Psychol. 41, 111-123.


Bonzo! -- and other famous apes

In the 1951 film, "Bedtime for Bonzo", starring a future President of the United States, , Hollywood used the theme of psychologists raising chimps in their home as an amusing storyline. See the video notes for details.

Susie, Joni, Duhong, Peter, Chim, Panzee, Gua, Vicki, Kanzi, Koko, Chantek

summary: enculturation but no speech

Several common themes emerge from a number of home-raised chimp studies. They clearly demonstrate the importance of the environment in determining the behavior of primates. Human encultured chimps acquire many human behaviors -- sleeping in beds, eating with utencils. There are also suggestions that home-raised chimps grow more quickly (perhaps due to diet?). We might also expect enhanced intellectual abilities due to enculturation. (See Premack, 199x).

language training studies studies (1970-)





contemporary cognitive studies

There are far too many to single out at this point -- see Tomasello and Call (1996) and Gomez (2004) for a review.

video examples

Tomasello's tool imitation studies

Boysen's "counting" chimps studies