Through a Window: My Thirty Years with the Chimpanzees of Gombe
Almost Human: A Journey into the World of Baboons
How Monkeys See the World: Inside the Mind of Another Species
Language and Species
Uniquely Human: The Evolution of Speech, Thought, and Selfless Behavior
At the end of his analysis of the logical shortcomings of Cartesian dualism—of the belief that what we call “mind” is some kind of entity that is distinct from our overt actions—Gilbert Ryle observed that those who are skeptical about the view that there is “a ghost in the machine” are not by implication degrading man to the level of a machine. Man, he wrote, “might after all, be a sort of animal, namely, a higher mammal.” But, he then added, “there has yet to be ventured the hazardous leap to the hypothesis that perhaps he is a man.”1
That the leap has not yet been successfully negotiated is clear from much that is still being written.2 Gilbert Ryle’s book may well therefore continue to have the influence in academic circles that it had when it first appeared. I mention it here because it is referred to in passing by one of the books—that by Dorothy Cheney and Robert Seyfarth—which form the subject of this review, and because the issues it discusses cast a shadow over all of them.
In the years since the publication of Ryle’s book a vast literature has grown up whose authors, with varying degrees of scholarship, have tried to persuade us that there is much to be learned about our “minds,” our behavior, and our origins by studying the ways of animals, and particularly those of apes and monkeys, with whom we are jointly classified in the zoological Order Primates. Some have tried to persuade us that human behavior basically accords with the ways that monkeys and apes are presumed to behave in the wild. Several have sought to show that apes, even if they cannot speak, have the ability to learn American Sign Language (ASL). Some go even further and tell us that by studying the way apes and monkeys spend their days we can learn not only about our own evolutionary past, but also how better to order our present troubled international relations.3 But despite all that has been written, the gulf between man and beast remains as wide as ever. The question is whether it is ever likely to be narrowed through study of our poor relations.
Jane Goodall’s Chimpanzees
Jane Goodall’s book Through a Window belongs to the first category of primatological literature. It is some thirty years since she started to become known for her accounts of her life with chimpanzees in the Gombe National Park on the eastern shore of Lake Tanganyika.4 Today, from what she tells us, Gombe is not far from being a large open zoo for three groups of chimpanzees, numbering in all about 160 animals.5 Clearly it is also an artificial wilderness, since the area around her beach-house, storehouses, and student cottages is furnished with numbers of feeding-boxes to which the chimpanzees and baboons in the park have free access.
The first accounts that she gave of her adventurous career not surprisingly encouraged many young graduate students to join her, usually for a few months at a time, at what is now called the Gombe Stream Research Centre. In addition, she employs Tanzanian helpers, and it would seem that at moments she must have had a team of as many as twenty helpers—one to every three or four of the Gombe chimpanzees, who must soon have learned that not only had they nothing to fear from their human companions, but that the latter were also their providers. The chimps’ relations with the baboons were also unnaturally close. One of the many excellent illustrations in Ms. Goodall’s book shows a male baboon copulating with a female chimpanzee. While much may therefore have been learned about the apes in the Gombe Park, one can hardly suppose that the circumstances were those that apply to chimpanzees living in what could be regarded as a “natural” environment.
Ms. Goodall had not had a university education before she was sent into the wild by Louis Leakey in the hope that by providing “a better understanding of the behavior of our closest relatives” she would at the same time provide “a new window onto our own past.” After a year and a half in Kenya she was admitted to Cambridge University6 as a Ph.D. student, returning to Africa in the mid-Sixties, as she puts it, “with at least some of the trappings of a scientist.” After her helpers had been taught to tell one chimpanzee from another, their job was to follow one or more of the animals through the day, noting what they did. By 1972 Ms. Goodall was away much of the time—for three months of the year she was lecturing at Stanford—and, as she says, when in Kenya she spent only “very short periods with the chimpanzees.” The picture that she now paints of her thirty-year odyssey, while built upon the observations she herself made in her first few years in Africa, is thus to a significant extent based upon the reports that she was provided by students and Tanzanian helpers. 7
I have followed Ms. Goodall’s accounts of chimpanzee behavior ever since I first heard her speak about the animal’s feeding habits at a symposium on Primates that was held in London in 1962. This was the first serious account that she gave of her time in the Gombe reserve, 8 and dealt with what she had learned in the previous fifteen months about the animal’s social behavior and feeding habits. She reported that the chimpanzee, while essentially a vegetarian, also ate insects, and that it sometimes used a blade of grass or a twig to winkle termites out of their mounds. On three occasions she had also seen a male chimpanzee eating a freshly killed small mammal—the first time a baby bush pig—while other chimpanzees looked on without being allowed to partake of the feast.
Since then her accounts of chimpanzees have not been consistent. About half of her new book is devoted to descriptions of the behavior of individual animals. The remainder takes up particular issues, such as “power,” the changes in group structure, fighting—and sex, of which there is a fair amount throughout the book.
Goodall had at first described the chimpanzee as an animal that lived peacefully in groups in which females were subordinate to the males, and in which any physically mature male could mate with any sexually receptive female. It then turned out that the males did not enjoy equal rights to the females, but lived in accordance with a hierarchical scale, with the most dominant animal having first pick at food or female. A few years later it turned out that the animal was not as peaceful as she had first assumed, but a creature that on occasion fought and killed its fellows—and sometimes even a baboon. More significant, she found that a male or female that had wandered from its fellows might be set upon by other chimpanzees, and that territorial fights—she calls them wars—occurred between groups of male chimpanzees of different bands.9 Today, while still extolling the loving relationship that mothers have with their young, she tells of some of them killing and eating their own babies.
She writes that the dominant male of a group may retain his “power” for several years before being ousted by a fellow mature male. His prior right to females as they come into full heat10—and solicit attention—and with whom they may form temporary “consort” relationships, does not however preclude the females from being mounted by “lower-ranking” males when the overlord male’s attention is elsewhere. She tells of one instance, when the dominant male’s attention was elsewhere, when three other males “sneaked” the opportunity to mount his female, all in the space of a few minutes.
Ms. Goodall in her more recent work tends to emphasize the exception at the expense of the usual. In her new book she multiplies the number of meat-eating episodes almost to the point at which the chimpanzee seems to be transformed from an essentially frugivorous animal into a hunter and omnivore. She also contradicts herself. Her story of the first occasion that she witnessed meat eating had a male taking a baby bush pig into a tree and consuming it by himself. Now she describes it as sharing it with a female. And while she reaffirms that in general chimpanzees neither share food nor help one another, she simultaneously leaves the impression that they do so frequently. She even has two or three chimpanzees cooperating in hunting a monkey as it moved through the trees. Her much-quoted observation about the animal using blades of grass or twigs to winkle out termites is re-emphasized out of all proportion.11 She tells us that when she reported it to Louis Leakey, he responded in a telegram saying that what she had seen meant that “now we must redefine tool, redefine Man, or accept chimpanzees as humans”—a statement that could only have been made by someone who was both unaware of the fact that there are several animal species that normally use stones and her objects for a variety of natural purposes, and that there are other characteristics besides using objects as tools that apply to the definition of Man.
A large part of her story is based on anecdote—“We must,” she says, “continue to collect anecdotes and, slowly, compile life histories.” As an example, she tells us, but without providing any evidence, that chimpanzees have been known to seize and eat human infants.12 Jane Goodall is also overwhelmingly anthropomorphic. She not only knows what chimpanzees have in their “minds” when they do the things they do, but also what their emotions are when they do them. “I have seldom found it difficult,” she writes, “to record facts in an orderly manner even during times of powerful emotional involvement.” “I can imagine, to some extent,” she goes on to say, “the pleasure of a female chimpanzee during the act of procreation,” by which she clearly implies copulation, since she goes on to say, “The feelings of her male partner are beyond my knowledge—as are those of the human male in the same context.” When a chimpanzee is gazing at trees through which colobus monkeys are moving, she knows that what they have in mind is the thought of a tasty bit of meat.
Without any reference to authority, Ms. Goodall asserts that “similarities in the structure of the brain and central nervous system have led to the emergence of similar intellectual abilities, sensitivities and emotions in our two species.” “If only we could however briefly see the world through the eyes of a chimpanzee,” she writes, “what a lot we should learn.” But even if it were possible to see the world in this way, Ms. Goodall does not tell us what we should expect to learn. My response to this particular suggestion would be that we would learn nothing meaningful to us as human beings. “The window into our own past” that Ms. Goodall set out to open is still shut, if indeed it exists even metaphorically. She ends her book with a statement of regret about the commercial and scientific exploitation of monkeys and apes, and a plea for their conservation.
Shirley Strum’s Baboons
It would have been surprising had the publicity associated with Ms. Goodall’s life not created a stereotype of attractive young women who, as Ms. Strum puts it in her Almost Human, forsake civilization “to commune with nature,” and to become “Miss Whosit among the wild whatsits.” She herself wanted none of this when she set out for the Kekopey cattle ranch in Kenya to study a troop of baboons that another graduate student had three years before named the Pumphouse Gang. A “city girl, born and bred,” she had majored in anthropology after “toying” with religion, abnormal psychology, and sociology. Other than that she attended lectures on human evolution given at Berkeley by Sherwood Washburn, with whom she continued as a graduate student, such indications as she gives of her undergraduate life do not imply that science, and in particular zoology, had played much part in her education.
Washburn, a physical anthropologist, had in the early 1960s become interested in field studies of monkeys, and together with one of his students had spent some time in Kenya observing the behavior of wild baboons and monkeys. One of the odd conclusions to which he had come was that although the animals live in bisexual groups, sexual interest played an insignificant, if indeed any, part in holding the groups together.13
Washburn appears to have had easy access to travel and research funds, and so was able to send students to follow in his African footsteps. Ms. Strum decided to embark on field studies of the baboon in the curious belief that they, rather than Jane Goodall’s chimpanzees, represented what she calls “the template” that would help us to an understanding of the evolutionary emergence of our own species, Homo Sapiens.
The baboons that frequented the scrubland—savannah—Kekopey ranch belonged to a species known in the vernacular as the Olive baboon. Apparently Ms. Strum had been taught that the savannah was the kind of environment from which “early humans” emerged. “Watching baboons on the savannah might help us understand,” so she writes, “the problems early humans may have faced and the solutions they found.”14
That baboons were a better “template” of man’s origins than chimpanzees was not the only one of Miss Strum’s preconceptions. When she set out on her travels she also believed that apes and monkeys lived in a constant state of war or aggression, which is how she supposes life was for our forebears. “A killer ape still lurked inside each of us,” she writes.
Many of her other pronouncements are somewhat novel. I wondered where she had learned such anatomical fantasies as, for example, that the canines of male baboons are “brittle,” and that when they fight, a male baboon will tear through its opponent’s “intestinal wall”—by which I assume she means abdominal wall. Whether this is in fact the baboon’s preferred point of attack seems to me open to doubt. Her knowledge of anatomy becomes even more fanciful when she tells us that, unlike those of the newly born baboons that I have studied, the penis of an infant baboon is as long as an arm or a leg, and that it could be taken for a “pink fifth leg.”15
Ms. Strum’s story about the sixty-strong Pumphouse Gang covered a period of thirteen years, during which she was away from Kekopey for varying and sometimes lengthy periods. The gang comprised six adult males, seventeen adult females, with juveniles and babies making up the remainder. She systematically got to know one animal from another, and they soon learned that they had nothing to fear from her. She provided food pellets to add to their natural diet, mainly of roots and fruit and supplemented on occasion with such items as scorpions, as well as what they pillaged from the crops that were grown on the farm. Like chimpanzees, baboons do not share food with one another, not even mothers with their young. But suddenly, Ms. Strum tells us, the Pumphouse Gang changed their habits and became meat eaters, hunting and killing young gazelles—and even sharing their kill. “The baboons were changing fast,” she writes, and “in 1973 a hundred kills were noted in twelve hundred hours of observation.”
In the same way as Jane Goodall had attracted helpers to Gombe, she had soon been joined by undergraduate and graduate students keen to join a lone but by now well-publicized American woman who was studying baboons in the wild, ostensibly in an effort to help in an understanding of human evolution. It is consequently difficult to tell how much of her story of thirteen years in the life of the Pumphouse baboons is based on her own observation and how much on what was reported by her helpers, including native Kenyans. She was a hard task-master. She confesses that she did not get on well with her “students.”16 They were certainly not there to write theses that challenged her views. “Conflict between the students themselves and between me and the students became inevitable…. Being the person in power…meant making enemies.” She was deeply hurt when she found that in their writings some students did not acknowledge their debt to her. 17 There were also differences between them about the extent to which the Pumphouse troop lived a natural life or one that had been transformed by human contact.
Ms. Strum became committed to the view that females, in a hierarchical scale, constituted the “core” of the Pumphouse gang, and that no dominance order existed among the males. The latter conclusion she regarded as so profound a scientific finding—so “shocking” a discovery, as she puts it—that she persuaded a foundation to provide the money for an international meeting of eighteen “world baboon experts” of her choice to “demonstrate simply and directly that male Pumphouse baboons did not have the traditional dominance hierarchy, while females did.” All but two of the eighteen “experts” were not only unimpressed by what she had to tell them, but some, she writes, even believed that she had “invented” her data. She was, however, unprepared to change her views, regardless of the fact that many parts of her story, as she told it, were open to interpretations that differed from hers. The meeting left her, she says, without a friend.
There is in fact nothing odd about the proposition that females form the core of a troop of baboons, and that members of one family group are closer to each other than they are to those of another. This is what one would in general expect with mammals, particularly in multiparous social species, or for that matter in a breeding colony of birds. What Ms. Strum means by the terms “group” and “dominance” is, however, unclear. Males came and went, she says, so “they couldn’t be expected to provide the stable core of the group.” But what, her reader may well ask, would a “group” be were males not an essential element? Would the females that formed the group wander at random in search of rampant males?
During one of her extensive return visits to the States, Ms. Strum heard that new owners of Kekopey had decided that the baboons were a pest, and were hunting them down. By now she was married to a Kenyan conservation officer, and with his help decided that the baboons—the gang had by now divided into three subgroups—should be collected and transported en masse to a more tolerant estate. The males and females were separately enticed into large cages, sedated as necessary, and then moved, first the cages with the females and infants, and then the males, with the females and infants being released first. Instead of making off on their own, the females kept returning day after day to the vicinity of the caged males, until they, too, were released. All the animals then moved off to regroup and establish territorial and other relations with whatever new groups of baboons they now encountered. Having committed herself to the idea that mature males were only itinerants in a female dominated society, Ms. Strum appears to have failed to see that this view did not accord with the fact that without the mature males with whom they had lived before, her translocated females were unprepared to make their own way in their new environment.
Other than the reported emergence of carnivorous habits, Ms. Strum’s well-illustrated book does not suggest that she either observed or had reported to her anything about the ways of baboons that was not already known. What characterizes her story is her anthropomorphic interpretations, and her personal identification with particular animals, for in this respect she resembles Jane Goodall. “Slowly and almost imperceptibly,” she writes,
I had become deeply involved with the animals. Just being with them created a strong emotional bond…. They were friends, in a very unusual sense. Unknowingly, they shared the joys of companionship and the intimate details of their lives with me. I laughed at their antics, delighted in the first steps of a new baby, feared that a youthful male bully would go too far and perhaps injure one of my favorite animals. And without my realizing it at the time, being with them satisfied most of my social needs without placing many demands on me…. I was in the unique position of being part of a group while remaining outside it, receiving many rewards without paying the price. The baboons touched my heart and mind without touching my body.
In so doing, however, they appear to have diluted whatever elements of scientific discipline she may have absorbed at Berkeley. Her book opens with a special note stating that it records “fact not fiction.” Her generalizations about the baboon “mind” do not, however, constitute fact, any more than is her naive interpretation of the concept of evolution that aggression is “the central [sic] cornerstone” in animal society.
The Mentality of Monkeys
Dorothy Cheney and Robert Seyfarth also believe that “just as one can learn about the origin of the human hand or brain by studying the anatomy of non-human primates, so research on non-human primate behavior can shed light on the origins of human language, cognition, and self-awareness.” To put this belief into perspective, they devote the first chapter of their book to a sketchy review of what philosophers have said about the concept of mind, and about the possibility of one person reading the mind of another, let alone understanding the mind of an animal. They do not, however, make it clear whether when they embarked as graduate students in 1977 on their field studies of the vervet monkey,18 they had already decided that what philosophers such as Wittgenstein and Ryle had declared was logically impossible would prove merely difficult for the keen animal observer. “Intellectually,” they write, “our approach to animal intelligence is a hybrid, combining the methods of behaviorists (who don’t believe in mentality) with many interpretations of mentalists,” an approach which they say “echoes a growing conviction in ethology that many aspects of animal behavior cannot be explained without ascribing some types of complex mental processes to animals.”
Their field work in the Amboseli National Park of Kenya was carried out in four phases between 1977 and 1988,19 with their attention directed mainly on three of the eleven social groups of vervet monkeys in the park, each comprising between one and seven adult males, two to ten adult females, and the rest juveniles and infants. Groups’ territories ranged from 11 to 100 hectares—averaging 28. Since it was impossible to see what every animal in a group was doing at any particular moment, a sampling method was adopted with an observer following and making notes for ten minutes at a time about what a single animal did when it left the tree in which it had spent the night. The presumably hundreds of separate “stills” were then collated to provide a picture of how vervets “interacted” with one another, and how the groups were organized.20
The study concentrated on five general features: “kinship, dominance, reciprocity, sexual attraction and group defense.” The basic sign of dominance which Cheney and Seyfarth assumed was very simple. Dominance is implied “when one animal approaches another and the other moves away.” “In some cases,” they write,
the dominant animal may take over the subordinate’s food, resting place, mate, or grooming partner…. If one individual is dominant to another on a given day, the chances are good that she will still be dominant days, weeks, months, or even years later.
On the further assumption that rigid hierarchical scales of dominance prevail among vervets, they also devised computer programs to predict whether interactions would change given, for example, that a high-ranking as opposed to a low-ranking female had a baby.
Cheney and Seyfarth conclude that, in general, vervet groups are organized in the same way as are those of other Old World monkeys. Since it can safely be assumed that the vervet sex ratio at birth is approximately equal, the socionomic ratio, that is to say the ratio of mature males to females, will normally be heavily biased in favor of females, who typically remain in the groups in which they were born. As they approach sexual maturity, males migrate from their natal groups and join neighboring groups—if they are not driven away as intruders. Cheney and Seyfarth tell us that during their lives males may “transfer” several times, or simply disappear.
A hierarchy of dominance exists among the mature females as well as with the males, among whom, we are also told, the order changes more frequently than it does among females. A “high-ranking” male may not have exclusive access to females, but Cheney and Seyfarth write that he nonetheless enjoys “an advantage over others in obtaining matings.”21 Quoting from a Ph.D. thesis written by another Amboseli observer, the authors tell us that no visible changes occur in the female vervet either “in physiology or behavior around the time of ovulation.”22 This has long been known, but it is not clear why the graduate student in question should have supposed that the fact that he or she was unable to discern changes in the sexual receptiveness of female vervets meant that male vervets were similarly handicapped. I doubt if a male vervet would be able to tell by her behavior whether a female observer was or was not feeling sexy at any particular moment.
During the thirteen-year period of observation covered by the book, the total population of vervets in the park fell, because of disease and predators, from about five hundred to thirty-five, and the eleven groups to four. Cheney and Seyfarth do not tell us how the constitution of these four related to that of the original eleven, or whether their computer studies had foretold what changes would occur, given the reduction of the size of the total population—or, indeed, whether their computer programs had any practical value at all. Nor do they say anything about the way new social groups of vervets are formed when males break away from their parent group either to join another group or to form a new one that manages to persist.23
Some of the issues they do raise sound profound as set out but, when pursued, turn out to have little intellectual or scientific significance. For example, we are told that most “interactions” among vervets occur in the groups to which they belong. This leads them to ask whether vervets in one group “recognize” individuals in adjacent groups. To obtain an answer to this question, they recorded a particular cry of animals in one group and played it back from a loudspeaker hidden not in the animals’ own territory but in that of a nearby group. The object of the experiment was to see whether the monkeys in a third adjacent group would be surprised to hear the call coming from an unexpected quarter. After four pages of text (describing some months of work), we learn that vervets “seemed [sic] to associate the vocalizations of individual members of other groups with those groups’ territories.” To the extent that the voices of different vervets may differ, one may well ask what else could they have expected.
They also provide a lengthy but speculative discussion of what they call “reciprocity” in the “interactions” between monkeys, and conclude that “until we find some way to measure the relative costs and benefits that individuals derive from interactions, almost any relationship can be seen as reciprocal (or asymmetrical), depending on how one chooses to measure the participants’ gains and losses.” Whether or not a way is found, the idea of applying the concept of cost-benefit analyses to such “interactions” as fur-grooming seems to me more than a little far-fetched. It is equally difficult to see the point of an inconclusive and lengthy discussion of the capacity of monkeys to classify objects “conceptually,” given that it ends with the statement that “Whether they [monkeys] are at all aware of what they are doing…remains to be determined.”
Cheney and Seyfarth’s chapters on the vocalization of vervets briefly take us away from their speculations about the “mind” of vervets. The alarm calls of male and female vervets differ, and we are told that they are acoustically specific for their three main predators—leopards, eagles and pythons. When reproduced through hidden loudspeakers in the absence of predators, the calls elicit the responses that the vervets would have made had their enemy been present. Apart from alarm calls, Cheney and Seyfarth believe that some other sounds that are made by vervets may have specific references. But once again, after a few pages of speculation, they end up with the negative statement that
although monkeys use vocalizations to signal about things and compare calls on the basis of their referents, we have no evidence that monkeys explicitly recognize the referential relations that hold between their calls and objects in the world around them.
Instead of reading pages that end by telling us that there is “no evidence that monkeys can label social relationships,” one would, perhaps, have been more interested to know whether the Amboseli vervets’ alarm calls are the same as those of vervets living, say, in the Kruger National Park some hundreds of miles away.
There is, in fact, little that is “intermediate” in Cheney and Seyfarth’s presumed philosophical approach to their subject. They answer questions such as “Do monkeys know as much about each other’s behavior,” with the empty statement—after elaborate argument—that “In the absence of some accessibility to his own mind, it is difficult to see how a monkey could distinguish between his own thoughts and beliefs and the thoughts and beliefs of others.” At the end of their first chapter, Cheney and Seyfarth wisely anticipate that a critical reader might well ask whether their analysis of vervet behavior has “revealed something about the essential nature of vervet monkeys or has it only told us something about ourselves?” The fact is that much of what they have written is permeated with the same anthropomorphism as characterizes Jane Goodall’s and Shirley Strum’s books. On the other hand, their speculations about the vervet’s “mind,” do at least show that “it” is no more elastic than is the animal’s behavior in the environment to which it is anchored.
Can Apes Talk?
If field studies of chimpanzees and monkeys throw little light on man’s origins and behavior, no more do laboratory studies that have been designed to reveal the “intelligence” of monkeys and apes. What has emerged is that while they are creatures that can be easily taught to solve fairly complicated problems, nothing that they are able to learn is, in general, beyond the capacity of other species of mammal, and even of birds—given of course that allowances are made for differences in their anatomical structure.24
The most interesting—and controversial—of recent studies of animal intelligence are those that were embarked upon in the hope that apes can be taught to communicate by means of American Sign Language. Apparently a few experimenters succeeded in getting their subjects to master a sign-vocabulary of several hundred items, but H.S. Terrace of Columbia, who began work with his celebrated chimpanzee Nim in the belief that his pupil was genuinely learning to “sign,” soon came to realize that in fact Nim was merely responding to cues that he himself was unwittingly giving. He then demonstrated—in what developed into a heated dispute—that this was also the case with the efforts that other experimenters had made to teach apes ASL. Moreover, Nim’s ASL turned out to be not a way of conversing, but a game associated with pleasurable reward. Above all Terrace found, as others have done since, that in its use of signs, the chimpanzee could not be taught to follow any syntactic rules of the kind that permit words or representational signs to make meaningful sentences. When Nim strung signs together, he did so at random.
In 1980 the subject was dispassionately reviewed in this journal by Martin Gardner,25 who having considered the arguments for and against, came down on the side of those who were skeptical about the idea that apes could be taught “to speak.” The subject has now been reviewed afresh by Derek Bickerton, a professor of linguistics, who in his book Language and Species points out that “there seems to be nothing in any animal communication system that corresponds even vaguely” to the grammatical items on which syntax depends. Animal calls, he writes, are made in isolation and convey “whole chunks of information” that human language would break up into meaningful units—for example, calls signifying danger or defense of territory. He emphasizes that the only aspect of ASL which a handful of apes have been patiently taught to acquire is the semantic—the representational aspects of objects or actions. For example, a chimpanzee can be taught to sign for “cup” or “apple.” In his absorbing book, Uniquely Human, Philip Lieberman also writes that apes cannot be trained to use or understand any syntactic rules.
Against the background of Oliver Sacks’s recent study of communication in deaf communities,26 and of the illuminating commentary on the subject in these pages by David Perlmutter,27 it would now seem that whatever view were taken of the results of experiments to teach apes ASL, it would bear little relation to the sign languages that are employed in communities of the deaf, or that are learned by children who become deaf after having learned to speak. The sign languages of the deaf have specific rules of grammar and syntax. They are true languages, articulated like any vocal language, and intertranslatable from one to another. In spoken English, as Perlmutter, puts it.
Adjectives are placed beside the nouns they modify; subjects, verbs, and objects are aligned in the right order; question words are placed in initial position; pronouns are put in the nominative or objective case according to their function in the sentence; verbs are put in a form that expresses tense and (in the present tense) whether or not the the subject is third-person singular.
Sign language, whether the American form or some other, has its own way of doing the corresponding things.
If one considers the question of human communication more generally, “the miracle,” as Perlmutter puts it, “is neither sign nor speech per se. The miracle is language.” That was, and remains, the critical evolutionary development that made man a unique primate, and one that released him from the immediate present within which apes and monkeys are tied, and by so doing opened for us human beings a world of our own creation, with a past, a present, and a future, one limitless in time and space. What we share with monkeys and apes is the basic anatomical pattern that differentiates all Primates from, say, the carnivores, ungulates, and rodents. Like them we have hands—or feet—that can grasp. Like them we enjoy stereoscopic and color vision. Like them, and unlike mammals with a strictly confined breeding season, we live in permanently bisexual groups. But it is what apes and monkeys do not share that makes us human—language.
When Did Language Emerge?
How, when, and where in man’s paleontological past the momentous jump into a world of language occurred is a question to which both Bickerton and Lieberman address themselves as an issue that has to be faced in relation to the general concept of Darwinian evolution. Here we need to remember that the concept of evolution does not belong to the category of theories which allow of predictions such, for example, as those that derive from Newtonian physics, and which underlie the achievements of space technology. While we have every reason to suppose that new characters and new species emerge as a result of genetic changes, isolation, and natural selection, it would never have been possible to predict how the future would unfold in the living world. The theory of evolution by natural selection is explanatory, not predictive. Bickerton and Lieberman are therefore attempting to find an answer to what Noam Chomsky regards, in the words of Bickerton, “as an issue of no more scientific interest than the origin of the heart.” Chomsky may well be right.
In their somewhat overlapping approach to the question, both touch on what it is possible to infer about the way the human brain, in parallel with the vocal tract, evolved, and about what clinical and experimental studies are now revealing about the way the brain works.
It has long been known that the outer part, or cortex, of the two cerebral hemispheres, which together make up the greater part of the brain, is differentiated into specific areas, two of which in the left hemisphere generally control speech and the comprehension of language. These two areas are connected with corresponding areas of the right cerebral hemisphere by fibers that form part of the corpus callosum, a thick body of nerve fibers that joins the two cerebral hemispheres. The right language areas are not involved in the motor aspects of speech and language, but are believed to be concerned with “comprehension,” especially with nonlinguistic cognitive phenomena such as our reactions to the events that we see. The same areas that are concerned with speech are now known to be the control centers for the sign languages of the deaf.
Neither of the two language areas is present in the cerebral cortex of apes and monkeys. In human beings, damage to either area caused by cerebral hemorrhages leads to varying degrees and kinds of speech defect and defects in the comprehension of language. Lieberman refers to experiments showing that “massive lesions” in or near the corresponding parts of the monkey brain have no effect on the calls the animal makes; nor does electrical stimulation of the cerebral cortex provoke vocal calls as does stimulation of an evolutionary older part that forms part of the base of the brain.
While antipathetic to Chomsky’s view that the issue of the origin of language is of no greater scientific significance than the evolution of some other part of the body, Lieberman does not deny that because of their advantages in natural selection “some aspects of the possible syntactic rules of all human languages” may have become a fixed part of our biological heritage. What he appears to dislike is the view that we are all born with an identical cerebral “language organ,” one that automatically equips a child of about the age of two with the ability to use the rules of a “universal grammar.” His argument is that the concept of a “universal grammar” denies the variability that characterizes all genetic inheritances.
I have to confess that here I fail to follow the nuances of an argument that seems to be pitched in terms far too black and white. No one knows how many mutations, or which genes acting in what order, became selected over the course of some millions of years in the development of the speech and language areas of the human brain, any more than we know the genetic steps that were involved in the evolution of the complex structure of the eye. Nor indeed do we yet know exactly which aspects of language are controlled or affected by the interconnections of the neurons of the language areas with those of other parts of the cortex, or with those of the more evolutionary ancient structures that are embedded deep in the brain—the basal ganglia and the cingulate gyrus. What we do know is that children vary—sometimes considerably—in the rate at which they learn to speak, but without in the end any effect on their ability to use articulate language, whether vocally or by way of signs. Lieberman’s dislike of the concept of a genetically determined “universal grammar” would be understandable were it to deny this degree of variation. I cannot believe that it does.28
Bickerton is not as concerned as is Lieberman about the degree of variability that needs to be assumed in a cerebral “language organ.” He is, however, equally interested in asking when it was that our ancestors started to acquire and use true language to create sentences with a high “transmission rate,” and which through the use of syntactic rules could convey an unlimited number of meanings. Deriving a clear-cut answer by way of inferences that are drawn from the shape of fossil cranial bones is, however, all but an impossible task. Paleoanthropology is not an exact science. Opinions always differ over the inferences that can be drawn from the scarce and fragmentary fossil human material available for study, whose antiquity is also subject to disagreement.29
Both Lieberman and Bickerton, however, agree that even were apes and monkeys endowed with a cerebral “language organ,” the anatomical structure of their vocal tract, while suited for grunts and chatterings, would preclude the possibility of speech, in particular because, as with four-legged mammals, their larynx is situated too high up in the neck and too close to the palate. The anatomical structure of the skulls of the Australopithecine fossil primates of South and East Africa, which it is widely claimed have a special place in the story of man’s descent, indicate that these creatures would have been similarly handicapped. According to Lieberman, the earliest definite indication of language that can be inferred from the primate fossil record relates to the remains of some human beings that were unearthed in a cave known by the name of Jebel Qafzeh in what is now Israel. The corpses had been buried in accordance with a ritual that included the incorporation of various grave goods, and the date of the deposits is estimated to be some 100,000 years BC. In shape and size the individuals whose fossilized bones were unearthed would have resembled modern man, and according to Lieberman, two of the skulls, as judged by endocranial casts, had enclosed brains that were furnished with the language areas that are the “biological bases of speech and syntax.” (On the basis of anatomical studies of a few fossil specimens, Lieberman has deduced that they spoke with a nasal accent, and had difficulties with a few vowels.) The symbolism associated with ritual burials would by itself imply that the Israelites of 100,000 years ago were people with a language.
How far back the history of modern man can be traced beyond Jebel Qafzeh is, however, pure guesswork. One view, for what it is worth, has it that the first men styled Homo erectus sprang into being in Africa some five million years ago, and that as the millennia passed, and as the ice ages came and went, the species spread northward into Europe and eastward into China and Indonesia, where isolated groups continued their independent evolution.
Beyond that simple generalization we are in a world of controversy and speculation, as is only too evident from The Human Revolution, the recent volume of essays edited by Paul Mellars and Christ Stringer. The trouble is that the number of human fossil remains, largely fragmentary, that have been found is too minute in relation to the enormous range in age of the deposits from which they have been unearthed, as well as to the vast distances that separate the deposits themselves, to allow of comparisons that can confidently define anatomical differences between different groups of prehistoric man.
A measure of the confusion to which the study of human fossils leads is indicated by the fact that we are told by Stringer that the lineage of the European branch of Homo erectus, better known as Neanderthal Man, covers a period of evolution “probably exceeding 200,000 years,” and that “there is little agreement as to whether this evolutionary lineage continued with the appearance of the first anatomically modern humans in the area about 35,000 BP [before the present], or was replaced, with or without accompanying gene flow.”
It would seem to me that the most reasonable conclusion that the facts allow us to draw about our ancestry is that as different groups of early man spread, they continued to evolve, but in different ways and at different rates, so that human beings who could fit into a modern crowd—in short, people who would be styled Homo sapiens—coexisted at least 100,000 years ago in some parts of the world such as Israel with archaic beetlebrowed cave dwellers who were living in other parts, for example Europe and China.
Bickerton suggests that Homo erectus first spoke a protolanguage which, despite limited syntactic rules, was adequate for the simple life of a food-gatherer and hunter who had also started to fashion stone implements, the quality of which slowly improved over a period of some million years before reaching its apogee in the fine bone and flint implements that were made by the Neanderthaloid European branch of Homo erectus, who, about 40,000 years ago, were also responsible for the remarkable cave paintings of bison and other animals that they hunted.
If one accepts the theory of evolution by natural selection, says Bickerton, “language is no more than an evolutionary adaptation” that had to have an antecedent of some kind. With protolanguage the antecedent that he suggests, Homo erectus got by for more than a million years before language emerged as we know it, endowed with effective rules of syntax, language that can transform “the representational mappings from sense data” into concepts that represent “entities that do not exist in the world.” The jump to language, Bickerton speculates, may have occurred “at a not very remote period” as a result of a dominant genetic mutation in a single Homo erectus—an African Eve—that brought about a change in the internal organization of the brain.
Whether such a dramatic mutation did occur is no more speculative than the view that Homo sapiens, with a more efficient syntactic ability than that possessed by Homo erectus, emerged as a result of an equally far-reaching mutation. All that now seems likely is that two human types may have coexisted for probably as long as a quarter of a million years, with Homo erectus eventually disappearing. As Lieberman has also argued, the cerebral changes that underlay the acquisition of true language by Homo sapiens developed in parallel with those changes in the anatomy of the vocal tract that made speech as we know it possible.
Us and the Ape
We have all heard that language separates man from the beast. This truism can now be taken to mean that syntactic language acts as a vehicle that transforms what Bickerton styles the primary representational system we have of the world around us, that is to say, what is immediately perceived, into a secondary representational system which through language makes it possible to communicate thoughts, ideas, and abstractions with our fellow beings. Jane Goodall uses empty words when she writes that “mentally, at least, it would seem that chimpanzees stand at the threshold of language acquisition.” Her apes stand where they have always stood, and where they will continue to stand, that is to say in the primary representational world to which they belong in the forests of central Africa. Even had the brains of chimpanzees undergone the miraculous genetic change that endowed man with the gift of language, even if, according to Lieberman, they had anything to say, they did not have vocal tracts that would have made it possible for them to speak.
For her part, Shirley Strum writes that watching baboons provides “not just examples but important principles” that concern “a starting point for the scenario of human evolution.” But what principles, and what starting point, she does not say. Not surprisingly, too, Cheney and Seyfarth’s exploration of the mind of the vervet monkey ends up in the same logical morass where all discussion of Ryle’s “ghost in the machine” ends, with the added disadvantage that their concern was not the human mind but a presumed animal mind.
Whatever scientific merit attaches to the study of monkeys and apes in the wild, it cannot be that it will tell us more about our evolutionary past than zoologists have long known. Nor do I understand why Jane Goodall and Shirley Strum believe that some special significance attaches to the fact that molecular biologists declare that all but a minute fraction of our “genetic material” is the same as that of the ape. They might equally have said that we share a high proportion of the chemical constituents of our genes with, say, the armadillo. What makes us human is the small amount that we do not share, and that accounts for the differences between the human and the ape brain, and particularly for those parts that control speech and the syntactic rules that transform vocalization into meaningful language. As Bickerton has indicated, simple calculation would show that there are hundreds of millions of ways whereby the words of the preceding sentence could be ordered, but with only one, because of syntax, making sense and encasing the thought that I wish to convey. It is little wonder that the importance of syntax is one of the few things about which professional linguists agree in their quest for the roots of the diverse languages that have separated the peoples of the world.
Bickerton must also surely be right when he suggests that the emergence of language ordered by grammar and syntactic rules was coincident with the emergence of Homo erectus. The precise nature of the grammatical rules that underlie syntax may have changed as different languages evolved in groups of Homo erectus in Africa, Europe, and Asia, but their function has never changed. Nor did the rules change because of the enormous increase that must have taken place in the lexical or semantic content of language as settled village life replaced that of the food gatherer, any more than they did with the development of the civilizations of Ancient Egypt, Greece, and Rome, or with the birth of modern science in the seventeenth century and its subsequent growth.
The power and sweep of the concept of evolution by natural selection are so vast that it is always difficult to comprehend how it could account for the myriad of forms of life that have appeared and disappeared over the billions of years since the emergence of a self-reproducing protein molecule. But it is a concept that we need if we want to “explain” the enormous diversity of the living world that we know, of the unique symbiotic relationship of animal and plant life, and the symbiotic relationships that exist within the animal world itself. Chomsky may well have irritated those who disagreed with him when he said that the question of man’s acquisition of a so-called language organ had no greater significance than the question of the origin of the heart.
But perhaps there is a difference after all. All vertabrates have hearts that exercise the same functions as do our own, and anatomically we face no problem when we compare the structure of one heart with that of another. But there is nothing with which to compare language. However it came about, there is no form of animal vocalization with which it can be functionally compared. Language exists sui generis. That is why we are what we are. And that is a mystery no less profound than is the origin of life itself.
Apes and Us: An Exchange October 10, 1991
Gilbert Ryle, The Concept of Mind (London: Hutchinson’s University Library, 1949). ↩
See, for example, Oliver Sacks’s “Neurology and the Soul,” The New York Review, November 22, 1990, and the various commentaries on J. R. Searle’s article “Consciousness, Explanatory Inversion or Cognitive Science,” in Behavioral and Brain Sciences, Vol. 13, No. 4 (1990). ↩
Frans de Waal, Peacemaking Among Primates (Harvard University Press, 1989). ↩
The park is a narrow strip of rugged land some ten miles long, and in places two miles wide, with its landward side enclosed by villages and its shoreline dotted with the huts of a thousand fishermen. ↩
In her early writings, the number that she gave for the population varied between fifty and a hundred. ↩
She writes that she was fortunate to be admitted to Cambridge, and “wanted to get my PhD, if only for the sake of Louis Leakey and the other people who had written letters in support of my admission.” ↩
Visits to the Gombe Park also had their dangers. One young girl was killed when she fell down a cliff, and four were abducted by marauders from Zaire and had later to be ransomed. ↩
Jane Goodall, “Feeding Behaviour of Wild Chimpanzees,” The Primates, Symposium No. 10, (London: The Zoological Society, 1962), pp. 39–48. ↩
One would guess from what she now writes, averaging in Gombe up to about fifty. ↩
While females are most receptive sexually when in heat, mating may take place at any time, even during pregnancy. ↩
During the first five years of my career as a scientist, spent as prosector to the Zoological Society of London, I got to “know” many captive chimpanzees. A mature female with whom I often played was in the habit of picking up a piece of straw in order to “manicure”—I can think of no better word—my nails. It never occurred to me to regard her as a tool user, any more than I felt an “empathy” with her when I offered her my head so that she could “groom” my hair. ↩
Years ago the same tale used to be told about baboons in South Africa, but again, there was no hard evidence behind it. The cynical explanation was that the story had been invented to cover the human crime of infanticide. ↩
Washburn’s belief that sex is not a social bond in monkey societies, which apparently was accepted by at least some of his students, was an inference drawn both from inadequate observations and the fact that seasonal variations occur in the births of the vervet monkey. It is a view that is controverted by a mass of direct observation. It is also worth noting that when Ellsworth Huntington made his wellknown analysis of American census data (Season of Birth), he found that the summer was the season of highest conception in the more northern states and the lowest in the hotter south. This seasonal change may have altered with the widespread introduction of air-conditioning, but there is no indication that the sexual impulses of American men and women have changed over the years. ↩
She does not mention the fact that Olive baboons, like most other baboons, are adapted to almost any kind of African habitat, other than the desert. The Chacma baboons of South Africa are as common in the mountainous area of the Cape as they are in the flat-land savannah of the eastern Karoo, in whose ranges of rocky hills and isolated rocky hillocks—kopjes—they make their sleeping quarters. At least that is how they lived in the years in which I grew up in South Africa. ↩
Her historical knowledge seems as idiosyncratic as her anatomical and zoological. She writes that “a Lord Wilberforce” misunderstood the concept of evolution when he “taunted” its proponents. Samuel Wilberforce was a distinguished Victorian cleric and Bishop of Oxford. In a celebrated debate at the 1866 Oxford meeting of the British Association for the Advancement of Science he, with the support of Richard Owen, the most prominent zoologist and anatomist of the day, clashed with T.H. Huxley about what they regarded as the weaknesses of Darwin’s newly enunciated concept of evolution by natural selection. There is no verbatim record of the exchanges that took place during the debate, but according to his biographer, Bishop Wilberforce, an elegant and fluent speaker, remarked that he would not look at monkeys as associated with his ancestors, an observation that drew from Huxley the retort that he would rather be descended from an ape than from a bishop. This is the only reference to Wilberforce’s interest in the subject of evolution in the second volume of the three-volume biography of his life by A.R. Ashwell and Reginald G. Wilberforce (London: John Murray, 1879–1882). ↩
Jane Goodall writes that she too at times had difficulties of a similar kind. ↩
It should perhaps be noted that the one name missing from the extensive list of people whom Ms. Strum thanks for the help she received, including those of the two who provided her with the photographs with which it is lavishly illustrated, is that of Deborah Ross, who appears on the title page as the artist responsible for the beautiful action drawings of baboons that appear at the head of each chapter. Nor is there any indication of where these were drawn. ↩
The vervet species is widespread in subequatorial Africa, and is found in a variety of habitats ranging from dense forest to desert. I am familiar with the animal, having watched it frequently in the wild, and also having used it in experimental laboratory studies of its reproductive cycle. I also carried out a study of the metrical differences between the teeth of vervets that were transplanted to St. Kitts in the West Indies in association with the slave trade of the seventeenth and eighteenth centuries, and those of their African cousins of today. ↩
When they were away in the US, observations continued to be made in accordance with their instructions by a large number of graduate students on leave from universities. ↩
Underlying this technique is the obvious assumption that the identities of different animals were not confused by different observers, and that no instances of grooming or mating were ever missed. ↩
Elsewhere they write that there is “no significant correlation between dominance rank and frequency of copulation.” ↩
In baboons and chimpanzees the skin of, and around, the external genitalia gradually swells during the first half of the menstrual cycle owing to the retention of fluid between and by its constituent cells. In my early days of research I found by laboratory experiment that this is caused by the action of estrogenic hormone. The fluid is abruptly excreted about the middle of the menstrual cycle when ovulation, if it takes place, occurs. This discovery helped define the time of ovulation in the menstrual cycle of all Old World Primates, including humans. ↩
Surveys of spider monkeys in the Barro Colorado Island in the isthmus of the Panama Canal made in 1932, 1933, and 1951 showed that this is what happens in this species, as no doubt it does in most, if not all, species of monkey. ↩
Trained chimpanzees are outstanding as performing animals, but it is impossible to judge whether, for example, chimp acrobats riding bicycles are any more remarkable than, say, seals that have been trained to press the bulbs of differently tuned old-fashioned motor-horns, and to respond to their conductor-trainer’s signs by playing out the opening bars of Beethoven’s Fifth Symphony. Way back in the days of ancient Rome, baboons were trained to pluck the strings of a zither and to pick out the letters of the alphabet. ↩
The New York Review, March 20, 1980. ↩
Oliver Sacks, Seeing Voices: A Journey into the World of the Deaf (University of California Press, 1989). ↩
David M. Perlmutter, “The Language of the Deaf,” The New York Review, March 28, 1991. ↩
Gerald Edelman’s far-reaching hypothesis of “neural Darwinism” is relevant here. See his Neural Darwinism (Basic Books, 1987) and also How We Know: Nobel Conference XX (Harper and Row, 1985). The former was reviewed by J.Z. Young in The New York Review, February 4, 1988. What it states is that the neurons of the developing brain compete with one another in a process of natural selection when forming interconnecting groups of cells with specific functions, and those neurons that fail to make the necessary connections die. It is a hypothesis that implies variability no less in the brain’s language and speech neural circuits than it does in any other of our inheritances, and helps to explain why no two individuals, not even identical twins, are ever exactly alike. The plasticity that characterizes the brain’s development and performance is well illustrated by the fact that all standard anatomical texts tell of brains lacking a corpus callosum turning up on rare occasions in a dissecting room—brains that presumably belonged to individuals who during life were judged normal. Bickerton also refers to observations that have been made on patients whose corpus callosum has been surgically divided in an effort to control epileptic seizures, and in experiments in which the right hemisphere has been anesthetized. The results do not appear to be sufficiently clear-cut to say precisely what part the right hemisphere of the brain normally plays in speech and the appreciation of language. Apparently it may take over the language function of the left hemisphere in lefthanded people. ↩
See, for example, The Human Revolution, edited by Paul Mellars and Chris Stringer (Princeton University Press, 1989); Tracks Through Time: Australian Natural History, Supplement No. 2 (1988), and Christopher B. Stringer, “The Emergence of Modern Humans,” Scientific American 263 (December 1990). ↩