Although few viewers of television wildlife shows are probably aware of it, in the world of scientiﬁc research there exist two very different schools of thought on how nonhuman minds may usefully be studied. The school that we are all familiar with from hours upon hours of National Geographic and Discovery Channel specials—and indeed from most popular books on the subject written by scientists and nonscientists alike—features chimpanzees and gorillas endlessly chattering away in sign language and dolphins pressing buttons on computer screens; this is the “animals compared to us” school of animal intelligence, and it is focused ﬁrmly on whether or not the things that we once thought were uniquely human can be coaxed out of animals, too.
It is a way of looking at animal minds that has a natural appeal to human beings. As a species we attach considerable importance to intelligence; we like to rank things; and, as arguably the most self-centered organisms on Earth, we see nothing at all out of the ordinary in establishing ourselves as the reference point to which all other species ought to be compared.
The “animals compared to us” approach goes back more than a century. It received great encouragement from the popularization of Darwin’s evolutionary theory, which seemed to imply that differences even between humans and other animals were a matter of degree and not kind; in its more popularized forms, which indeed persist to today, evolution was seen as a seamless continuum of progress over time, perfectly mirrored in a seamless continuum of complexity among present-day organisms from amoebas to man.
Reviewing the classic studies of problem-solving ability in animals conducted in the half century following the appearance of Origin of Species, the British psychologist Lawrence Weiskrantz observed that it seemed to be “almost an account of how one would select animal candidates for the British civil service.”1 More recently, surveys have found that people from a wide variety of educational and social backgrounds show a similar eagerness to rank the relative intelligence of animals, and, interestingly, all ﬁll in their scorecards pretty much the same when given a list of familiar species: primates at the top, followed by dogs, cats, pigs, horses, cows, sheep, chickens, and turkeys.
Many of the recent studies of animal intelligence that have been so widely popularized are, at their core, driven by much the same impulse. They tend to focus on animals that humans can easily relate to (lizards, slugs, and clams rarely star in these shows) and implicit in their set-up is the question, “How close is species X to us?” Can a chimpanzee do arithmetic? Can a dolphin use a sentence? Can a gorilla read a map? Aside from the obvious entertainment appeal of such experiments—circuses featuring performing animals have been around for many more centuries than animal researchers have, so there is no surprise here—these experiments have an appeal precisely because they seem to be getting at the question most of us want to know: How smart are they? And by our ever so self-centered deﬁnition, the more they act like humans, the smarter they must be.
SCIENCE WITH AN AGENDA
A fact not generally brought out in 60 minutes of television featuring animals doing clever things with blocks or computers is that some well known scientists of the “animals compared to us” school have tied their research agenda to a very explicit political agenda. Scientists such as primate researcher Sue Savage-Rumbaugh have, in their writing, made clear their belief that the more other species can be shown to act like humans, the more deserving of rights they must be.
Savage-Rumbaugh, who has conducted well-known experiments in teaching language to chimpanzees, has stated that her goal is to break down the “boundary” that man has erected between humans and other animals, a boundary she says is “being policed” by scientiﬁc orthodoxy. It is a boundary that, she writes, has “led us blindly to exploit the world of nature” and is “alienating ourselves psychologically from other creatures on this planet.” She believes that her research and that of others supports granting “semi-human legal status to apes.”2
Other primate researchers have made similar statements, and been energetic in presenting their research as an explicit assault on the barrier between humans and other animals. Indeed many of their experiments are designed speciﬁcally to produce exceptions to the supposed rules that deﬁne humanity uniquely: language, mathematics, use of symbols, use of tools, use of tools to make other tools, and so forth.
SMART HOW, NOT HOW SMART
The other school of research into the minds of animals, a school far less well known to the general public, takes what is often termed an “ecological” approach. One reason this school gets less attention is that it embodies a more subtle and complex philosophical stance. It is not so easy to explain in video clips. It is more ambiguous and less certain in its results and conclusions. Doubt does not make good television; but, as Marc Hauser very effectively demonstrates in his new book, Wild Minds, it very often does make for good science.
The ecological approach starts by recognizing that every animal on Earth has been evolving for just as long as every other animal on Earth. Thus it is absurd to think that differences in the minds of animals reﬂect some sort of stunted growth or failure to progress on the part of some organisms compared to others. Rather, differences must reﬂect adaptations to different ways of life and different environments. To ecologically oriented students of the animal mind, the interesting question is not how “smart” animals are compared to humans, but rather why they possess the unique mental attributes they do. Even more interesting, how are their minds wired to perform the cognitive tasks essential for survival in a unique ecological niche? Inherent in this approach is a recognition that animal minds are often very different from one another, even as they share some features in common. Inherent in this approach, too, is a philosophical stance that it does not even make sense to ask “who’s the smartest,” for the true answer is “they all are.” It would make as much sense to ask, “Who has the best kind of nose, an elephant or a shark?”
Marc Hauser is the soul of tact in discussing the famous experiments of his more telegenic colleagues, but he leaves no doubt in Wild Minds that he is ﬁrmly in the ecological camp. Hauser, a professor of psychology at Harvard University, has spent many years studying primates and birds in both the ﬁeld and the laboratory. He clearly likes animals; more than that, he clearly is fascinated by them, and what makes him tick is a powerful yearning to understand what makes them tick.
I mention this because there has been a tendency among the more enthusiastic advocates for animals’ humanlike mental abilities to paint skeptics like Hauser as a bunch of reductionist spoilsports, cold ﬁsh, with hearts and souls as machinelike as (supposedly) animals are in their rigid view. Hauser is certainly skeptical. But his skepticism, one feels, has precisely the same source as his attraction for animals and his interest in them in the ﬁrst place: he really wants to understand what it is like to be an animal, and as a scientist he knows that the only way even to have a prayer of ﬁnding out is by being one’s own best devil’s advocate. Above all, Hauser sees evolutionary theory as the key to helping us reach that goal.
REMEMBERING 10,000 HIDING PLACES
“Animals do have thoughts and emotions,” Hauser writes.
To understand what animals think and feel, however, we must look at the environments in which they evolved. All animals are equipped with a set of mental tools for solving ecological and social problems. Some of the tools for thinking are universal, shared by insects, fish, reptiles, birds, and mammals, including humans. The universal tool kit provides animals with a basic capacity to recognize objects, count, and navigate. Divergence from the universal tool kit occurs when species confront unique ecological or social problems... The only way to understand how and what animals think is to evaluate their behavior in light of both universal and specialized tool kits.
Contemplating the astounding variety of specialized tool kits out there is in itself a mind-opening experience for anyone starting from the usual human assumption that intelligence can be ranked on a linear scale. The Clark’s nutcracker is a bird that feeds on the seeds of the pinyon pine. In late summer the birds begin to gather the seeds as they ripen and hide them in crevices or beneath the soil. The birds cache literally tens of thousands of seeds apiece in thousands of separate locations, and then return months later during winter to retrieve most of them. Field observations and lab experiments have established that they do so by actually remembering the locations, not just by digging around by chance (as squirrels do).
Sheep can tell apart dozens of individual members of a ﬂock by visual recognition of their faces. Tunisian desert ants can travel half a kilometer from their nest, a dime-sized opening in the unmarked sand, and ﬁnd their way unerringly back home. Brown thrashers can learn up to 1,200 different songs. We know how we might try to learn to do such tasks, by making notes, or making up mnemonic devices, or trying to put things into categories, yet the remarkable thing is that these animals do such things without the use of any such symbolic aids. Their minds really are different from ours.
Hauser leads us through the experiments and ﬁeld studies that attempt to ﬁgure out how these animals are doing such things that are so out of our own ken. One of the most admirable things about Wild Minds is that he does not try to hide from us the confusion, misinterpretations, and incorrect conclusions that have beset many who venture onto this territory. That might sound like the ingredients of a dismal and unsatisfying tale, but it actually has the opposite effect—of drawing us into and sharing the adventure of discovery. It also serves an important goal that, while never quite stated as such explicitly, is clearly close to Hauser’s heart: to explain to a public brought up on furry animal stories why skepticism is not a dirty word. For the fact is, we are fooled over and over again by our tendency to jump to the conclusion that when an animal performs some feat of the mind it must be doing precisely what we would be doing under similar circumstances.
MONKEY SEE, MONKEY DO
Hauser’s discussion of imitation in animals offers a particularly good case study of this point. Many animals exhibit behaviors that they appear to have learned by observing what another animal does. For example, black rats in Israel’s Jerusalem-pine forests have learned to strip the scales off of pine cones to eat the seeds within, a skill that rats living elsewhere do not have, nor do they acquire such a skill in the lab when given pine cones. But if a human “demonstrates” how to strip open a pine cone, the rats do learn to do so. Rat pups also learn when raised with adults that have the skill. If we saw this in humans, we would not hesitate to say that the uneducated pups and adults had learned by imitating the action they observed.
Yet when further experiments were done, it turned out that naive rats learn just as well when no one shows them “how” to do it, but rather when they are simply presented a pine cone that has already been partially stripped. The presentation of a partially stripped cone in effect encourages a rat to experiment with it and acquire the technique on its own. No teaching or imitation has taken place after all.
Likewise, while everyone knows that monkeys do what monkeys see, in fact, careful experiments have shown that imitation in monkeys and even in chimpanzees is not at all what it seems to be. When humans imitate others’ behavior, what they focus on is the goal and purpose of the action. (As the researcher Michael Tomasello put it, they understand the action as “cleaning the window,” not “moving the hand in a circular motion on the surface of the window while holding a cloth.”3) But although both chimpanzees and orangutans can “imitate arbitrary body movements, they fail to imitate actions that have a goal-directed component such as opening a jar,” Hauser writes.
In one of Tomasello’s experiments that Hauser describes, a human demonstrator picked up a T-shaped rake and then used it to pull toward him some small pieces of food that had been placed out of reach. Chimpanzees and two-year-old children watched. The chimpanzees “learned something about the rake’s connection to food,” but did not imitate what the demonstrator did; instead they messed around with the rake until they found some action on their part that worked. The children on the other hand were able without prompting to precisely reproduce what the demonstrator had done.
The point is not to show that humans are “better” than chimps, but rather just to emphasize that we are so conditioned to seeing things through our eyes that we are ever ready to jump to conclusions about what animals are doing. And, demonstrably, we are often wrong when we do so, though it can take an awful lot of experimentation and careful thinking to reach that conclusion. Isolated anecdotes of animals’ clever or unusual behaviors can be intriguing and compelling and can suggest ideas for new studies and experiments, Hauser writes, but the reason he is so cautious about taking them on face value is that experience has shown how easily misled we all can be.
Other interesting examples in Wild Minds of animal behavior that prove, on careful examination, to be very different from what they might at ﬁrst blush seem include deceptive behavior by monkeys, counting in many animals, and recognition of mirror images. The last is an area where Hauser and his coworkers at Harvard have done a number of pioneering studies that have shaken up the conventional and (still oft-repeated) view that apes and humans can recognize themselves in a mirror while monkeys and all other animals cannot. Hauser found that some monkeys do pass the so called “dye mark test,” in which an animal is anesthetized and a brightly colored mark placed on its forehead; the animal is then allowed to look at its mirror image and observed to see whether it touches the spot or otherwise shows that it recognizes that a change has occurred in its own appearance.
Hauser’s results showed that what determines whether or not an animal passes the test may be far more complicated than has been thought and may have less to do with self-awareness than has been claimed by some researchers. A species that considers a direct stare from another member of the same species to be a major threat may be averse to looking in a mirror in the ﬁrst place, for example, and so may never even have the opportunity to make the connection between the mirror image and itself. Although Hauser is careful to acknowledge that the jury is still out on who is right and who is wrong about which species have self-recognition ability, he makes a powerful and convincing case that isolated observations are almost surely going to be wrong, given how many variables may inﬂuence an animal’s behavior on such tests. It is clear from his discussion that to get an answer will require a whole series of experiments that can sequentially control for such variables.
“LITTLE FURRY HUMANS”
Recently, some of the “animals compared to us” school, joined by a wave of popular writers about animal intelligence such as Jeffrey Masson, have made a particular point of attacking the scientiﬁc “establishment” for ruling out from consideration anecdotes of animal cleverness. The scientiﬁc orthodoxy is painted as being pedantic or, worse, explicitly motivated by an intention to deny animals their due. Masson for example alleges that scientists have “a restricted sense of valid criteria.” Donald Grifﬁn, a researcher who has been at the vanguard of scientists arguing that many species possess humanlike consciousness, has denounced the “behavioristic taboo” that in his view has led scientists to be “brainwashed” into rejecting “suggestive evidence” of animals’ feelings and thoughts.
It has become something of a slogan and article of faith among animal rightsniks and their scientiﬁc allies that the supposed scientiﬁc orthodoxy, by rejecting anecdotal evidence, is really trying to put a stopper on the idea that animals have thoughts and feelings at all. Bernard Rollin, an animal-rightist philosopher, has written, for example, that “talk of animal thought and feeling” had by the 1930s been “banished from the legitimate purview of scientiﬁc inquiry,” and “this legacy continues even today.”
At the same time, as the cognitive scientist Jacques Vauclair observes, there has been an upping of the ante in the signiﬁcance attributed to animal thoughts and feelings by the “compared to us” school. Some of this is the result of deliberately anthropomorphic terminology: Animal vocalizations are “symbols” and “signs”; interactions between animals are “exchanges”; an instinctive inhibition of consanguineous mating is an “incest ban”; an ability to recognize other individuals and their social status in the group is “respect for others”; an act of assistance to another is “altruism” or “moral sense”; regular habits are “social rules”; and retaliation against aggressive conduct is “revenge” or even “just war.”4
Interestingly, a recent survey conducted among faculty and students in animal science, zoology, and veterinary medicine at Oregon State University found that an overwhelming majority (from 75 to 100 percent of each group in each department) agreed with the proposition that animals “have the ability to think.” In fact, the scientists were more likely to agree with the statement than were English Department faculty (67 percent). The researchers who conducted the survey concluded that they could ﬁnd no empirical evidence to support Rollin’s contention that “respectable” scientists have “banished” the notion that animals have thoughts and feelings.5
Hauser’s book is perhaps a more eloquent answer to the charge, for even as he tactfully questions anecdotal evidence and the ante-upping of so many other popularizers of the subject, his explicit aim is to get at the thoughts and feelings that animals so obviously do have—even if it is far from obvious precisely what those thoughts and feelings always are. His basic point is that if we try to make animals into little furry versions of humans, we miss the most remarkable stories about their minds. To truly learn how animals navigate, use numbers, recognize individuals, use and fashion tools, and learn about their environment we have to drop our preconceptions. The truth, as he shows, is often stranger and far more remarkable than all of the myths and fairy tales we might initially think we prefer to the cold, remorseless logic of science.
OUR UNIQUE SENSE OF SELF
The ecological approach does lead to the conclusion, however, that there are some fundamental differences between human minds and those of other species. Hauser’s review of neuroimaging studies of brain-damaged humans leads him to the conclusion that in humans, and in animals too, emotions play a central role in decision-making. The ability to make rational decisions breaks down when attachments are severed between the emotional center, the amygdala, and the planning area, the prefrontal cortex. But despite the many similarities between both human and animal emotions and human and animal brains, there are some differences that ecologically minded studies have pointed out. Particularly on the basis of experiments in animals and human infants on what is called “theory of mind,” Hauser concludes that certain forms of understanding and emotion do not exist outside of our own species.
The development of theory of mind in humans is captured in a fascinating experiment Hauser describes in which children watch a little show featuring two puppets, Sally and Anne. Sally tells Anne she is going to put the ball they have been playing with in the box and leave the room. Sally goes out; while she is out Anne takes the ball out of the box and hides it under the bed. Sally then comes back in. The child who is watching the show is then asked, Where will Sally look for the ball? Three-year olds usually say under the bed. So do many autistic children. But four-year olds understand that Sally, by being out of the room, does not know something that they themselves do know, and answer that Sally will look in the box.
Analogous experiments in apes have tried very hard to establish whether or not they, too, have a theory of mind. Although the analysis of these experiments is often complex and fraught with methodological and philosophical pitfalls, Hauser makes the case that nonhuman primates ﬂunk the tests much as three-year-old children do. And that does have some very interesting implications about the capacity for morality. Hauser concludes that because of a lack of theory of mind, the emotions that underlie morality simply do not exist in non-human animals—emotions such as empathy, sympathy, shame, guilt, and loyalty: “Empathy requires not only a sense of self, but a sense of self that ties into what it would be like to be someone else.” That such discontinuities between the minds of humans and the minds of other species should exist in no way contradicts the evolutionary ties that link all of life; humans and apes diverged from a common ancestor some 6 million years ago, and a lot of evolution can go on in that time. It is no more wonderful that our minds diverge in some ways than that humans walk bipedally and chimpanzees do not.
At places, readers of Wild Minds will probably wish that Hauser was clearer in showing how the experiments he describes so well individually relate to the larger points he is trying to get across, and at places he is obviously bending over so far backward to avoid offending the scientiﬁc colleagues whose interpretations he disagrees with that he does not come out and clearly say what he clearly believes. The result is that it is sometimes difﬁcult to follow the logic that leads him to the conclusions about human-animal differences he does present. His numerous pop-culture allusions and repertoire of very old jokes sometime come off more as perfunctory attempts to be engaging than as illuminating or genuinely apropos. It is hard for scientists writing to a popular audience to resist the temptation of attempting to emulate the ﬂash of a genuinely gifted popularizer like Steven Pinker, but most probably should.
But these are minor complaints; Marc Hauser has done a groundbreaking job of bringing to a general audience a way of thinking about animal minds that is all too rarely presented to the public. He has the unimpeachable credentials to do so, and he has shown in Wild Minds more eloquently than anyone else probably could how it is possible to be fascinated by animals, to respect their remarkable and unique solutions to the complex business of making a living, and at the same time to resist the beguiling and ever-so-popular temptation to see them as furry little people.
From Wild Minds: What Animals Really Think by Marc Hauser. © 2000 by Marc Hauser. Reprinted by permission of Henry Holt & Company.
I suggest that although animals have the mental tools to distinguish between living and nonliving things, to use object motion to generate expectations about behavior, and to have emotional experiences about their interactions with the physical and psychological world, they lack the moral emotions or moral senses. They lack the capacity for empathy, sympathy, shame, guilt, and loyalty. The reason for this emotional hole in their lives is that they lack a fundamental mental tool: self awareness. Although there is some evidence that animals have self-recognition, recognizing and distinguishing their own bodies from others, there is no evidence that they are actually aware of their own beliefs and desires, and how they differ from those of their peers. Without self-awareness, the kind of empathic response that appears to underline some of the experimental results described is impossible. Empathy requires not only a sense of self, but a sense of self that ties into what it would be like to be someone else. Empathy represents an emotional fusion of self and other.
If my claim about self-awareness is correct, then animals must also lack a deep understanding of death. To understand death as a system of beliefs, as opposed to simply responding to dead things, individuals must have a sense of self-awareness. Without an understanding of death, they cannot exhibit moral outrage when one individual kills another, though they may well feel a great loss. Feeling a loss, and understanding what it means to die, are two different things. What, then, do animals know about the process of dying, and the categorical distinction between life and death?
Death ties into an understanding of morality on a number of levels. For one thing, understanding death reveals a deep sense of time, of what the past has been like and what the future holds. Further, many of our laws are designed to protect others from being killed or killing themselves, because we see life as precious. To appreciate such laws, and support them, one must have an understanding of death.
Understanding what animals know about death can be reduced to the problem of whether animals understand the difference between living and nonliving things. Ants provide an excellent starting point. The sociobiologist Ed O. Wilson noticed that when ants find a dead colony member, they drag it out of the area and then drop it off. The sign post for “dead” in the ant is their smell. In particular, when ants die, they emit a chemical called oleic acid. It turns out that if you cover a live ant with oleic acid, colony members deposit this individual out of the nest area. Ants seem to equate oleic acid with death, and leave no room for exceptions. If “dead” means more than a drop of oleic acid, then ants lack in understanding of death. They can distinguish between dead and living things, but can be readily fooled by a mischievous experimenter.
To have an understanding of death is to have specific beliefs about what it means to be dead. Children under the age of 10 years old tend to believe that dead is simply the opposite of living, that is, not living. In this sense, inanimate objects are dead, and so are animate objects that have their eyes closed and fail to move. As the developmental psychologist Susan Carey has pointed out, some time after the age of 10 years, children undergo a conceptual transformation that provides them with a new way of thinking about life and death. This conceptual transformation teaches them that only animate things can die, that upon dying, the brain no longer works, that if they die the same things will happen to them, that killing is bad, and that they have the potential to end another’s life as well as their own. In this sense, a psychologically interesting representation of death depends on self-awareness, and a richly textured set of beliefs about the meaning of life.