No More Learning

But increasingly researchers are able to tie genes to the brain.
A promising example is the F0XP2 gene, associated with a speech and language disorder in a large family. 50 The aberrant nucleotide has been found in every impaired member of the family (and in one unrelated person with the same syndrome), but it was not found in any of the unimpaired members, nor was it found in 364 chromosomes from unrelated normal people. The gene belongs to a family of genes for transcription factors -- proteins that turn on other genes -- that are known to play important roles in embryogenesis. The mutation disrupts the part of the protein that
? ? ? ? ? ? ? ? ? latches onto a particular region of DNA, the key step in turning on the right gene at the right time. The gene appears to be strongly active in fetal brain tissue, and a closely related version found in mice is active in the developing cerebral cortex. These are signs, according to the authors of the study, that the normal version of the gene triggers a cascade of events that help organize a part of the developing brain.
The meaning of genetic variation among normal individuals (as opposed to genetic defects that cause a disorder) also has to be thought through with care. An innate difference among people is not the same thing as an innate {50} human nature that is universal across the species. Documenting the ways that people vary will not directly reveal the workings of human nature, any more than documenting the ways that automobiles vary will directly reveal how car engines work. Nonetheless, genetic variation certainly has implications for human nature. If there are many ways for a mind to vary genetically, the mind must have many genetically influenced parts and attributes that make the variation possible. Also, any modern conception of human nature that is rooted in biology (as opposed to traditional conceptions of human nature that are rooted in philosophy, religion, or common sense) must predict that the faculties making up human nature show quantitative variation, even if their fundamental design (how they work) is universal. Natural selection depends on genetic variation, and though it reduces that variation as it shapes organisms over the generations, it never uses it up completely. 51
Whatever their exact interpretation turns out to be, the findings of behavioral genetics are highly damaging to the Blank Slate and its companion doctrines. The slate cannot be blank if different genes can make it more or less smart, articulate, adventurous, shy, happy, conscientious, neurotic, open, introverted, giggly, spatially challenged, or likely to dip buttered toast in coffee. For genes to affect the mind in all these ways, the mind must have many parts and features for the genes to affect. Similarly, if the mutation or deletion of a gene can target a cognitive ability as specific as spatial construction or a personality trait as specific as sensation-seeking, that trait may be a distinct component of a complex psyche.
Moreover, many of the traits affected by genes are far from noble. Psychologists have discovered that our personalities differ in five major ways: we are to varying degrees introverted or extroverted, neurotic or stable, incurious or open to experience, agreeable or antagonistic, and conscientious or undirected. Most of the 18,000 adjectives for personality traits in an unabridged dictionary can be tied to one of these five dimensions, including such sins and flaws as being aimless, careless, conforming, impatient, narrow, rude, self-pitying, selfish, suspicious, uncooperative, and undependable. All five of the major personality dimensions are heritable, with perhaps 40 to 50 percent of the variation in a typical population tied to differences in their genes. The unfortunate wretch who is introverted, neurotic, narrow, selfish, and undependable is probably that way in part because of his genes, and so, most likely, are the rest of us who have tendencies in any of those directions as compared with our fellows.
It's not just unpleasant temperaments that are partly heritable, but actual behavior with real consequences. Study after study has shown that a willingness to commit antisocial acts, including lying, stealing, starting fights, and destroying property, is partly heritable (though like all heritable traits it is exercised more in some environments than in others). 52 People who commit {51} truly heinous acts, such as bilking elderly people out of their life savings, raping a succession of women, or shooting convenience store clerks lying on the floor during a robbery, are often diagnosed with "psychopathy" or "antisocial personality disorder. "53 Most psychopaths showed signs of malice from the time they were children. They bullied smaller children, tortured animals, lied habitually, and were incapable of empathy or remorse, often despite normal family backgrounds and the best efforts of their distraught parents. Most experts on psychopathy believe that it comes from a genetic predisposition, though in some cases it may come from early brain damage. 54 In either case genetics and neuroscience are showing that a heart of darkness cannot always be blamed on parents or society.
And the genes, even if they by no means seal our fate, don't sit easily with the intuition that we are ghosts in machines either. Imagine that you are agonizing over a choice -- which career to pursue, whether to get married, how to vote, what to wear that day. You have finally staggered to a decision when the phone rings. It is the identical twin you never knew you had. During the joyous conversation it comes out that she has just chosen a similar career, has decided to get married at around the same time, plans to cast her vote for the same presidential candidate, and is wearing a shirt of the same color -- just as the behavioral geneticists who tracked you down would have bet. How much discretion did the "you" making the choices actually have if the outcome could have been predicted in advance, atleastprobabilistically,basedoneventsthattookplacein~yourmother'sFallopiantubesdecadesago?
The fourth bridge from biology to culture is evolutionary psychology, the study of the phylogenetic history and adaptive functions of the mind. 55 It holds out the hope of understanding the design or purpose of the mind -- not in
some mystical or teleological sense, but in the sense of the simulacrum of engineering that pervades the natural world. We see these signs of engineering everywhere: in eyes that seem designed to form images, in hearts that seem
? ? ? ? ? ? ? designed to pump blood, in wings that seem designed to lift birds in flight.
Darwin showed, of course, that the illusion of design in the natural world can be explained by natural selection. Certainly an eye is too well engineered to have arisen by chance. No wart or tumor or product of a big mutation could be lucky enough to have a lens, an iris, a retina, tear ducts, and so on, all perfectly arranged to form an image. Nor is the eye a masterpiece of engineering literally fashioned by a cosmic designer who created humans in his own image. The human eye is uncannily similar to the eyes of other organisms and has quirky vestiges of extinct ancestors, such as a retina that appears to have been installed backwards. 56 Today's organs are replicas of organs in our ancestors whose design worked better than the alternatives, thereby enabling them to become our ancestors. 57 Natural selection is the only physical process we know of {52} that can simulate engineering, because it is the only process in which how well something works can play a causal role in how it came to be.
Evolution is central to the understanding of life, including human life. Like all living things, we are outcomes of natural selection; we got here because we inherited traits that allowed our ancestors to survive, find mates, and reproduce. This momentous fact explains our deepest strivings: why having a thankless child is sharper than a serpent's tooth, why it is a truth universally acknowledged that a single man in possession of a good fortune must be in want of a wife, why we do not go gentle into that good night but rage, rage against the dying of the light. Evolution is central to understanding ourselves because signs of design in human beings do not stop at the heart or the eye. For all its exquisite engineering, an eye is useless without a brain. Its output is not the meaningless patterns of a screen saver, but raw material for circuitry that computes a representation of the external world. That representation feeds other circuits that make sense of the world by imputing causes to events and placing them in categories that allow useful predictions. And that sense-making, in turn, works in the service of motives such as hunger, fear, love, curiosity, and the pursuit of status and esteem. As I mentioned, abilities that seem effortless to us -- categorizing events, deducing cause and effect, and pursuing conflicting goals -- are major challenges in designing an intelligent system, ones that robot designers strive, still unsuccessfully, to duplicate.
So signs of engineering in the human mind go all the way up, and that is why psychology has always been evolutionary. Cognitive and emotional faculties have always been recognized as nonrandom, complex, and useful, and that means they must be products either of divine design or of natural selection. But until recently evolution was seldom explicitly invoked within psychology, because with many topics, folk intuitions about what is adaptive are good enough to make headway. You don't need an evolutionary biologist to tell you that depth perception keeps an animal from falling off cliffs and bumping into trees, that thirst keeps it from drying out, or that it's better to remember what works and what doesn't than to be an amnesiac.
But with other aspects of our mental life, particularly in the social realm, the function of a faculty is not so easy to guess. Natural selection favors organisms that are good at reproducing in some environment. When the environment consists of rocks, grass, and snakes, it's fairly obvious which strategies work and which ones don't. But when the relevant environment consists of other members of the species evolving their own strategies, it is not so obvious. In the game of evolution, is it better to be monogamous or polygamous? Gentle or aggressive? Cooperative or selfish? Indulgent with children or stern with them? Optimistic, pragmatic, or pessimistic?
For questions like these, hunches are unhelpful, and that is why {53} evolutionary biology has increasingly been brought into psychology. Evolutionary biologists tell us that it is a mistake to think of anything conducive to people's well-being -- group cohesion, the avoidance of violence, monogamous pair bonding, aesthetic pleasure, self-esteem -- as an "adaptation. " What is "adaptive" in everyday life is not necessarily an "adaptation" in the technical sense of being a trait that was favored by natural selection in a species' evolutionary history. Natural selection is the morally indifferent process in which the most effective replicators outreproduce the alternatives and come to prevail in a population. The selected genes will therefore be the "selfish" ones, in Richard Dawkins's metaphor -- more accurately, the megalomaniacal ones, those that make the most copies of themselves. 58 An adaptation is anything brought about by the genes that helps them fulfill this metaphorical obsession, whether or not it also fulfills human aspirations. And this is a strikingly different conception from our everyday intuitions about what our faculties were designed for.
The megalomania of the genes does not mean that benevolence and co-operation cannot evolve, any more than the law of gravity proves that flight cannot evolve. It means only that benevolence, like flight, is a special state of affairs in need of an explanation, not something that just happens. It can evolve only in particular circumstances and has to be supported by a suite of cognitive and emotional faculties. Thus benevolence (and other social motives) must be dragged into the spotlight rather than treated as part of the furniture. In the sociobiological revolution of the 1970s, evolutionary biologists replaced the fuzzy feeling that organisms evolve to serve the greater good with deductions of what kinds of motives are likely to evolve when organisms interact with offspring, mates, siblings, friends, strangers, and adversaries.
When the predictions were combined with some basic facts about the hunter-gatherer lifestyle in which humans
? ? ? ? ? evolved, parts of the psyche that were previously inscrutable turned out to have a rationale as legible as those for depth perception and the regulation of thirst. An eye for beauty, for example, locks onto faces that show signs of health and fertility -- just as one would j predict if it had evolved to help the beholder find the fittest mate. 59 The emotions of sympathy, gratitude, guilt, and anger allow people to benefit from cooperation without being exploited by liars and cheats. 60 A reputation for toughness and a thirst for revenge were the best defense against aggression in a world in which one could not call 911 to summon the police. 61 Children acquire spoken language instinctively but written language only by the sweat of their brow, because spoken language has been a feature of human life for tens or hundreds of millennia whereas written language is a recent and slow-spreading invention. 62
None of this means that people literally strive to replicate their genes. If that's how the mind worked, men would line up outside sperm banks and {54} women would pay to have their eggs harvested and given away to infertile couples. It means only that inherited systems for learning, thinking, and feeling have a design that would have led, on average, to enhanced survival and reproduction in the environment in which our ancestors evolved. People enjoy eating, and in a world without junk food, that led them to nourish themselves, even if the nutritional content of the food never entered their minds. People love sex and love children, and in a world without contraception, that was enough for the genes to take care of themselves.
The difference between the mechanisms that impel organisms to behave in real time and the mechanisms that shaped the design of the organism over evolutionary time is important enough to merit some jargon. A proximate cause of behavior is the mechanism that pushes behavior buttons in real time, such as the hunger and lust that impel people to eat and have sex. An ultimate cause is the adaptive rationale that led the proximate cause to evolve, such as the need for nutrition and reproduction that gave us the drives of hunger and lust. The distinction between proximate and ultimate causation is indispensable in understanding ourselves because it determines the answer to every question of the form "Why did that person act as he did? " To take a simple example, ultimately people crave sex in order to reproduce (because the ultimate cause of sex is reproduction), but proximately they may do everything they can not to reproduce (because the proximate cause of sex is pleasure).
The difference between proximate and ultimate goals is another kind of proof that we are not blank slates. Whenever people strive for obvious rewards like health and happiness, which make sense both proximately and ultimately, one could plausibly suppose that the mind is equipped only with a desire to be happy and healthy and a cause-and-effect calculus that helps them get what they want. But people often have desires that subvert their proximate well-being, desires that they cannot articulate and that they (and their society) may try unsuccessfully to extirpate. They may covet their neighbor's spouse, eat themselves into an early grave, explode over minor slights, fail to love their stepchildren, rev up their bodies in response to a stressor that they cannot fight or flee, exhaust themselves keeping up with the Joneses or climbing the corporate ladder, and prefer a sexy and dangerous partner to a plain but dependable one. These personally puzzling drives have a transparent evolutionary rationale, and they suggest that the mind is packed with cravings shaped by natural selection, not with a generic desire for personal well-being. Evolutionary psychology also explains why the slate is not blank. The mind was forged in Darwinian competition, and an inert medium would have been outperformed by rivals outfitted with high technology -- with acute perceptual systems, savvy problem-solvers, cunning strategists, and sensitive feedback circuits. Worse still, if our minds were truly malleable they would be easily manipulated by our rivals, who could mold or condition us {55} into serving their needs rather than our own. A malleable mind would quickly be selected out.
Researchers in the human sciences have begun to flesh out the hypothesis that the mind evolved with a universal complex design. Some anthropologists have returned to an ethnographic record that used to trumpet differences among cultures and have found an astonishingly detailed set of aptitudes and tastes that all cultures have in common. This shared way of thinking, feeling, and living makes us look like a single tribe, which the anthropologist Donald Brown has called the Universal People, after Chomsky's Universal Grammar. 63 Hundreds of traits, from fear of snakes to logical operators, from romantic love to humorous insults, from poetry to food taboos, from exchange of goods to mourning the dead, can be found in every society ever documented. It's not that every universal behavior directly reflects a universal component of human nature -- many arise from an interplay between universal properties of the mind, universal properties of the body, and universal properties of the world. Nonetheless, the sheer richness and detail in the rendering of the Universal People comes as a shock to any intuition that the mind is a blank slate or that cultures can vary without limit, and there is something on the list to refute almost any theory growing out of those intuitions. Nothing can substitute for seeing Brown's list in full; it is reproduced, with his permission, as an appendix (see p. 435).
The idea that natural selection has endowed humans with a universal complex mind has received support from other quarters. Child psychologists no longer believe that the world of an infant is a blooming, buzzing confusion, because they have found signs of the basic categories of mind (such as those for objects, people, and tools) in young babies. 64 Archaeologists and paleontologists have found that prehistoric humans were not brutish troglodytes but exercised
? ? ? ? ? ? ? ? their minds with art, ritual, trade, violence, cooperation, technology, and symbols. 65 And primatologists have shown that our hairy relatives are not like lab rats waiting to be conditioned but are outfitted with many complex faculties that used to be considered uniquely human, including concepts, a spatial sense, tool use, jealousy, parental love, reciprocity, peacemaking, and differences between the sexes. 66 With so many mental abilities appearing in all human cultures, in children before they have acquired culture, and in creatures that have little or no culture, the mind no longer looks like a formless lump pounded into shape by culture.
But it is the doctrine of the Noble Savage that has been most mercilessly debunked by the new evolutionary thinking. A thoroughly noble anything is an unlikely product of natural selection, because in the competition among genes for representation in the next generation, noble guys tend to finish last. Conflicts of interest are ubiquitous among living things, since two animals cannot both eat the same fish or monopolize the same mate. To the extent that {56} social motives are adaptations that maximize copies of the genes that produced them, they should be designed to prevail in such conflicts, and one way to prevail is to neutralize the competition. As William James put it, just a bit too flamboyantly, "We, the lineal representatives of the successful enactors of one scene of slaughter after another, must, whatever more pacific virtues we may also possess, still carry about with us, ready at any moment to burst into flame, the smoldering and sinister traits of character by means of which they lived through so many massacres, harming others, but themselves unharmed. "67
From Rousseau to the Thanksgiving editorialist of Chapter 1, many intellectuals have embraced the image of peaceable, egalitarian, and ecology-loving natives. But in the past two decades anthropologists have gathered data on
life and death in pre-state societies rather than accepting the warm and fuzzy stereotypes. What did they find? In a nutshell: Hobbes was right, Rousseau was wrong.
To begin with, the stories of tribes out there somewhere who have never heard of violence turn out to be urban legends. Margaret Mead's descriptions of peace-loving New Guineans and sexually nonchalant Samoans were based on perfunctory research and turned out to be almost perversely wrong. As the anthropologist Derek Freeman later documented, Samoans may beat or kill their daughters if they are not virgins on their wedding night, a young man who cannot woo a virgin may rape one to extort her into eloping, and the family of a cuckolded husband may attack and kill the adulterer. 68 The ! Kung San of the Kalahari Desert had been described by Elizabeth Marshall Thomas as "the harmless people" in a book with that title. But as soon as anthropologists camped out long enough to accumulate data, they discovered that the ! Kung San have a murder rate higher than that of American inner cities. They learned as well that a group of the San had recently avenged a murder by sneaking into the killer's group and executing every man, woman, and child as they slept. 69 But at least the ! Kung San exist. In the early 1970s the New York Times Magazine reported the discovery of the "gentle Tasaday" of the Philippine rainforest, a people with no words for conflict, violence, or weapons. The Tasaday turned out to be local farmers dressed in leaves for a photo opportunity so that cronies of Ferdinand Marcos could set aside their "homeland" as a preserve and enjoy exclusive mineral and logging rights. 70
Anthropologists and historians have also been counting bodies. Many intellectuals tout the small numbers of battlefield casualties in pre-state societies as evidence that primitive warfare is largely ritualistic. They do not notice that two deaths in a band of fifty people is the equivalent of ten million deaths in a country the size of the United States. The archaeologist Lawrence Keeley has summarized the proportion of male deaths caused by war in a number of societies for which data are available:71 {57}
? ? ? ? ? ? ? ? ? ? ? The first eight bars, which range from almost 10 percent to almost 60 percent, come from indigenous peoples in South America and New Guinea. The nearly invisible bar at the bottom represents the United States and Europe in the twentieth century and includes the statistics from two world wars. Moreover, Keeley and others have noted that native peoples are dead serious when they carry out warfare. Many of them make weapons as damaging as their technology permits, exterminate their enemies when they can get away with it, and enhance the experience by torturing captives, cutting off trophies, and feasting on enemy flesh. 72
Counting societies instead of bodies leads to equally grim figures. In 1978 the anthropologist Carol Ember calculated that 90 percent of hunter-gatherer societies are known to engage in warfare, and 64 percent wage war at least once every two years. 73 Even the 90 percent figure may be an underestimate, because anthropologists often cannot study a tribe long enough to measure outbreaks that occur every decade or so (imagine an anthropologist studying the peaceful Europeans between 1918 and 1938). In 1972 another anthropologist, W. T. Divale, investigated 99 groups of hunter-gatherers from 37 cultures, and found that 68 were at war at the time, 20 had been at war five to twenty-five years before, and all the others reported warfare in the more distant past. 74 Based on these and other ethnographic surveys, Donald Brown includes conflict, rape, revenge, jealousy, dominance, and male coalitional violence as human universals. 75
It is, of course, understandable that people are squeamish about acknowledging the violence of pre-state societies. For centuries the stereotype of the {58} savage savage was used as a pretext to wipe out indigenous peoples and steal their lands. But surely it is unnecessary to paint a false picture of a people as peaceable and ecologically conscientious in order to condemn the great crimes against them, as if genocide were wrong only when the victims are nice guys.
The prevalence of violence in the kinds of environments in which we evolved does not mean that our species has a death wish, an innate thirst for blood, or a territorial imperative. There are good evolutionary reasons for the members of an intelligent species to try to live in peace. Many computer simulations and mathematical models have shown that cooperation pays off in evolutionary terms as long as the cooperators have brains with the right combination of cognitive and emotional faculties. 76 Thus while conflict is a human universal, so is conflict resolution. Together with all their nasty and brutish motives, all peoples display a host of kinder, gentler ones: a sense of morality, justice, and community, an ability to anticipate consequences when choosing how to act, and a love of children, spouses, and friends.
77 Whether a group of people will engage in violence or work for peace depends on which set of motives is engaged, a topic I will pursue at length in later chapters.
Not everyone will be comforted by such reassurances, though, because they eat away at the third cherished assumption of modern intellectual life. Love, will, and conscience are in the traditional job description for the soul and have always been placed in opposition to mere "biological" functions. If those faculties are "biological" too -- that is, evolutionary adaptations implemented in the circuitry of the brain -- then the ghost is left with even less to do
? ? ? ? ? ? ? and might as well be pensioned off for good.
<< {59} >> Chapter 4
Culture Vultures
Like all men of Babylon, I have been proconsul; like all, I have been a slave. Look here -- my right hand has no index finger. Look here -- through this gash in my cape you can see on my stomach a crimson tattoo -- it is the second letter, Beth. On nights when the moon is full, this symbol gives me power over men with the mark of Gimel, but it subjects me to those with the Aleph, who on nights when there is no moon owe obedience to those marked with the Gimel. In the half-light of dawn, in a cellar, standing before a black altar, I have slit the throats of sacred bulls. Once, for an entire lunar year, I was declared invisible -- I would cry out and no one would heed my call, I would steal bread and not be beheaded. . . .
I owe that almost monstrous variety to an institution -- the Lottery -- which is unknown in other nations, or at work in them imperfectly or secretly. 1
Jorge Luis Borges's story "The Lottery in Babylon" is perhaps the best depiction of the idea that culture is a set of roles and symbols that mysteriously descend on passive individuals. His lottery began as the familiar game in which a winning ticket was rewarded by a jackpot. But to enhance the suspense the operators added a few numbers that presented the ticket holder with a fine rather than a reward. They then imposed prison sentences on those who did not pay the fines, and the system expanded into a variety of nonmonetary punishments and rewards. The lottery became free, compulsory, omnipotent, and increasingly mysterious. People began to speculate on how it worked and whether it even continued to exist.
At first glance human cultures do appear to have the monstrous variety of a Borgesian lottery. Members of Homo sapiens ingest everything from maggots and worms to cow urine and human flesh. They bind, cut, scar, and stretch body parts in ways that would make the most perforated Western {60} teenager wince. They sanction kinky sexual practices like teenagers receiving daily fellatio from younger boys and parents arranging marriages between their five- year-olds. The apparent caprice of cultural variation leads naturally to the doctrine that culture lives in a separate universe from brains, genes, and evolution. And this separation depends in turn on the concept of a slate that is left blank by biology and written upon by culture. Now that I have tried to convince you that the slate is not blank, it is time to put culture back into the picture. That will complete the consilience that runs from the life sciences through the sciences of human nature to the social sciences, humanities, and arts.
In this chapter I will lay out an alternative to the belief that culture is like a lottery. Culture can be seen instead as a part of the human phenotype: the distinctive design that allows us to survive, prosper, and perpetuate our lineages. Humans are a knowledge-using, cooperative species, and culture emerges naturally from that lifestyle. To preview: The phenomena we call "culture" arise as people pool and accumulate their discoveries, and as they institute conventions to coordinate their labors and adjudicate their conflicts. When groups of people separated by time and geography accumulate different discoveries and conventions, we use the plural and call them cultures. Different cultures, then, don't come from different kinds of genes -- Boas and his heirs were right about that -- but they don't live in a separate world or stamp a shape onto formless minds either.
The first step in connecting culture to the sciences of human nature is to recognize that culture, for all its importance, is not some miasma that seeps into people through their skin. Culture relies on neural circuitry that accomplishes the feat we call learning. Those circuits do not make us indiscriminate mimics but have to work in surprisingly subtle ways to make the transmission of culture possible. That is why a focus on innate faculties of mind is not an alternative to a focus on learning, culture, and socialization, but rather an attempt to explain how they work.
Take the case of a person's mother tongue, which is a learned cultural skill par excellence. A parrot and a child both learn something when exposed to speech, but only the child has a mental algorithm that extracts words and rules from the sound wave and uses them to utter and understand an unlimited number of new sentences. The innate endowment for language is in fact an innate mechanism for learning language. 2 In the same way, for children to learn about culture they cannot be mere video cameras that passively record sights and sounds. They must be equipped with mental machinery that can extract the beliefs and values underlying other people's behavior so that the children themselves can become competent members of the culture. 3
Even the humblest act of cultural learning -- imitating the behavior of a {61} parent or a peer -- is more complicated than it looks. To appreciate what goes on in our minds when we effortlessly learn from other people, we
? ? ? ? ? ? ? ? ? ? have to imagine what it would be like to have some other kind of mind. Fortunately, cognitive scientists have imagined it for us by plumbing the minds of robots, animals, and people whose minds are impaired.
The artificial intelligence researcher Rodney Brooks, who wants to build a robot capable of learning by imitation, immediately faced this problem when he considered using techniques for learning that are common in computer science:
The robot is observing a person opening a glass jar. The person approaches the robot and places the jar on a table near the robot. The person rubs his hands together and then sets himself to removing the lid from the jar. He grasps the glass jar in one hand and the lid in the other and begins to unscrew the lid by turning it counter-clockwise. While he is opening the jar, he pauses to wipe his brow, and glances at the robot to see what it is doing. He then resumes opening the jar. The robot then attempts to imitate the action. [But] which parts of the action to be imitated are important (such as turning the lid counter- clockwise), and which aren't (such as wiping your brow)? . . . How can the robot abstract the knowledge gained from this experience and apply it to a similar situation? 4
The answer is that the robot has to be equipped with an ability to see into the mind of the person being imitated, so that it can infer the person's goals and pick out the aspects of behavior that the person intended to achieve the goal. Cognitive scientists call this ability intuitive psychology, folk psychology, or a theory of mind. (The "theory" here refers to the tacit beliefs held by a person, animal, or robot, not to the explicit beliefs of scientists. ) No existing robot comes close to having this ability.
Another mind that finds it difficult to infer others' goals is the chimpanzee's. The psychologist Laura Petitto was the principal sign language trainer for the animal known as Nim Chimpsky and lived with him for a year in a university mansion. At first glance Nim seemed to "imitate" her washing the dishes, but with an important difference. A dish was not necessarily any cleaner after Nim rubbed it with a sponge than before, and if he was given a spotless dish, Nim would "wash" it just as if it were dirty. Nim didn't get the concept of "washing," namely using liquid to make something clean. He just mimicked her rubbing motion while enjoying the sensation of warm water over his fingers. Many laboratory experiments have shown something similar. Though chimpanzees and other primates have a reputation as imitators ("Monkey see, monkey do"), their ability to imitate in the way people do -- {62} replicating another person's intent rather than going through the motions -- is rudimentary, because their intuitive psychology is rudimentary. 5
A mind unequipped to discern other people's beliefs and intentions, even if it can learn in other ways, is incapable of the kind of learning that perpetuates culture. People with autism suffer from an impairment of this kind. They can grasp physical representations like maps and diagrams but cannot grasp mental representations -- that is, they cannot read other people's minds. 6 Though they certainly imitate, they do it in bizarre ways. Some are prone to echolalia, repeating other people's utterances verbatim rather than extracting the grammatical patterns that would allow them to compose their own sentences. Autistics who do learn to speak on their own often use the word you as if it were their own name, because other people refer to them as you and it never occurs to them that the word is defined relative to who is addressing it to whom. If a parent knocks over a glass and says, "Oh, damn! " an autistic child might use oh damn as the word for a glass -- disproving the empiricist theory that normal children can learn words merely by associating sounds and events that overlap in time. None of this is a consequence of low intelligence. Autistic children can be competent (or even savants) when solving other problems, and retarded children without autism don't show the same foibles with language and imitation. Autism is an innate neurological condition with strong genetic roots. 7 Together with robots and chimpanzees, people with autism remind us that cultural learning is possible only because neurologically normal people have innate equipment to accomplish it.
Scientists often interpret the long childhood of members of Homo sapiens as an adaptation that allows children to acquire the vast store of information from their culture before striking out on their own as adults. If cultural learning depends on special psychological equipment, we should see the equipment up and running early in childhood. And indeed we do.
Experiments show that one-and-a-half-year-old babies are not associationists who connect overlapping events indiscriminately. They are intuitive psychologists who psych out other people's intentions before copying what they do. When an adult first exposes a baby to a word, as in "That's a toma" the baby will remember it as the name of the toy the adult was looking at at the time, not as the name of the toy the baby herself was looking at. 8 If an adult fiddles with a gadget but indicates that the action was an accident (by saying "Whoops! "), a baby will not even bother trying to imitate him. But if the adult does the same thing but indicates that he intended the action, the baby will imitate him. 9 And when an adult tries and fails to accomplish something (like trying to press the button on a buzzer, or trying to string a loop around a peg), the baby will imitate what the adult tried to do, not what he did do. 10 As someone who studies language acquisition in children, I have continually been amazed at how early they "get" the logic of
? ? ? ? ? ? ? ? language, availing themselves of {63} most of the spoken vernacular by the age of three. 11 That, too, may be an attempt by the genome to get our culture-acquiring apparatus online as early in life as the growing brain can handle it. Our minds, then, are fitted with mechanisms designed to read the goals of other people so we can copy their intended acts. But why would we want to? Though we take it for granted that acquiring culture is a good thing, the act of acquiring it is often spoken of with scorn. The longshoreman and philosopher Eric Hoffer wrote, "When people are free to do as they please, they usually imitate each other. " And we have a menagerie of metaphors that equate this quintessentially human ability with the behavior of animals: along with monkey see, monkey do, we have aping, parroting, sheep, lemmings, copycats, and a herd mentality.
Social psychologists have amply documented that people have a powerful urge to do as their neighbors do. When unwitting subjects are surrounded by confederates of the experimenter who have been paid to do something odd, many or most will go along. They will defy their own eyes and call a long line "short" or vice versa, nonchalantly fill out a questionnaire as smoke pours out of a heating vent, or (in a Candid Camera sketch) suddenly strip down to their underwear for no apparent reason. 12 But the social psychologists point out that human conformity, no matter how hilarious it looks in contrived experiments, has a genuine rationale in social life -- indeed, two rationales. 13
The first is informational, the desire to benefit from other people's knowledge and judgment. Weary veterans of committees say that the IQ of a group is the lowest IQ of any member of the group divided by the number of people in the group, but that is too pessimistic. In a species equipped with language, an intuitive psychology, and a willingness to cooperate, a group can pool the hard-won discoveries of members present and past and end up far smarter than a race of hermits. Hunter-gatherers accumulate the know-how to make tools, control fire, outsmart prey, and detoxify plants, and can live by this collective ingenuity even if no member could re-create it all from scratch. Also, by coordinating their behavior (say, in driving game or taking turns watching children while others forage), they can act like a big multi-headed, multi-limbed beast and accomplish feats that a die-hard individualist could not. And an array of interconnected eyes, ears, and heads is more robust than a single set with all its shortcomings and idiosyncrasies. There is a Yiddish expression offered as a reality check to malcontents and conspiracy theorists: The whole world isn't crazy.
Much of what we call culture is simply accumulated local wisdom: ways of fashioning artifacts, selecting food, dividing up windfalls, and so on. Some anthropologists, like Marvin Harris, argue that even practices that seem as arbitrary as a lottery may in fact be solutions to ecological problems. 14 Cows really {64} should be sacred in India, he points out; they supply food (milk and butter), fuel (dung), and power (by pulling plows), so the customs protecting them thwart the temptation to kill the goose that laid the golden egg. Other cultural differences may have a rationale in reproduction. 15 In some societies, men live with their paternal families and support their wives and children; in others, they live with their maternal families and support their sisters and nieces and nephews. The second arrangement tends to be found in societies where men have to spend long periods of time away from home and adultery is relatively common, so they cannot be sure that their wives' children are theirs. Since the children of a man's mother's daughter have to be his biological kin regardless of who has been sleeping with whom, a matrilocal family allows men to invest in children who are guaranteed to carry some of their genes.
Of course, only Procrustes could argue that all cultural practices have a direct economic or genetic payoff. The second motive for conformity is normative, the desire to follow the norms of a community, whatever they are. But this, too, is not as stupidly lemminglike as it first appears. Many cultural practices are arbitrary in their specific form but not in their reason for being. There is no good reason for people to drive on the right side of the road as opposed to the left side, or vice versa, but there is every reason for people to drive on the same side. So an arbitrary choice of which side to drive on, and a widespread conformity with that choice, make a great deal of sense. Other examples of arbitrary but coordinated choices, which economists called "cooperative equilibria," include money, designated days of rest, and the pairings of sound and meaning that make up the words in a language.
Shared arbitrary practices also help people cope with the fact that while many things in life are arranged along a continuum, decisions must often be binary. 16 Children do not become adults instantaneously, nor do dating couples become monogamous partners. Rites of passage and their modern equivalent, pieces of paper like ID cards and marriage licenses, allow third parties to decide how to treat ambiguous cases -- as a child or as an adult, as committed or as available -- without endless haggling over differences of opinion.
And the fuzziest categories of all are other people's intentions. Is he a loyal member of the coalition (one that I would want to have in my foxhole) or a quisling who will bail out when times get tough? Does his heart lie with his father's clan or with his father-in-law's? Is she a suspiciously merry widow or just getting on with her life? Is he dissing me or just in a hurry? Initiation rites, tribal badges, prescribed periods of mourning, and ritualized forms of address may not answer these questions definitively, but they can remove clouds of suspicion that would otherwise hang over people's heads.
When conventions are widely enough entrenched, they can become a kind of reality even though they exist only in
? ? ? ? ? ? ? ? people's minds. In his book The Construction of Social Reality (not to be confused with the social construction of {65} reality), the philosopher John Searie points out that certain facts are objectively true just because people act as
if they are true. 17 For example, it is a matter of fact, not opinion, that George W. Bush is the forty-third president of the United States, that O. J. Simpson was found not guilty of murder, that the Boston Celtics won the NBA World Championship in 1986, and that a Big Mac at the time of this writing) costs $2. 62. But though these are objective facts, :hey are not facts about the physical world, like the atomic number of cadmium or the classification of a whale as a mammal. They consist in a shared understanding in the minds of most members in a community, usually agreements to grant (or deny) power or status to certain other people.
Life in complex societies is built on social realities, the most obvious examples being money and the rule of law. But a social fact depends entirely on the willingness of people to treat it as a fact. It is specific to a community, as we see when people refuse to honor a foreign currency or fail to recognize the sovereignty of a self-proclaimed leader. And it can dissolve with changes in the collective psychology, as when a currency becomes worthless through hyperinflation or a regime collapses because people defy the police and army en masse. (Searle points out that Mao was only half right when he said that "political power grows out of the barrel of a gun. " Since no regime can keep a gun trained on every last citizen, political power grows out of a regime's ability to command the fear of enough people at the same time. ) Social reality exists only within a group of people, but it depends on a cognitive ability present in each individual: the ability to understand a public agreement to confer power or status, and to honor it as long as other people do.
How does a psychological event -- an invention, an affectation, a decision to treat a certain kind of person in a certain way -- turn into a sociocultural fact -- a tradition, a custom, an ethos, a way of life? We should understand culture, according to the cognitive anthropologist Dan Sperber, as the epidemiology of mental representations: the spread of ideas and practices from person to person. 18 Many scientists now use the mathematical tools of epidemiology (how diseases spread) or of population biology (how genes and organisms spread) to model the evolution of culture. 19 They have shown how a tendency of people to adopt the innovations of other people can lead to effects that we understand using metaphors like epidemics, wildfire, snowballs, and tipping points. Individual psychology turns into collective culture.
Culture, then, is a pool of technological and social innovations that people accumulate to help them live their lives, not a collection of arbitrary roles and symbols that happen to befall them. This idea helps explain what makes cultures different and similar. When a splinter group leaves the tribe and is cut off by an ocean, a mountain range, or a demilitarized zone, an innovation on one side of the barrier has no way of diffusing to the other side. As each group
{66} modifies its own collection of discoveries and conventions, the collections will diverge and the groups will have different cultures. Even when two groups stay within shouting distance, if their relationship has an edge of hostility they may adopt behavioral identity badges that advertise which side someone is on, further exaggerating any differences. This branching and differentiation is easily visible in the evolution of languages, perhaps the clearest example of cultural evolution. And as Darwin pointed out, it has a close parallel in the origin of species, which often arise when a population splits in two and the groups of descendants evolve in different directions. 20 As with languages and species, cultures that split apart more recently tend to be more similar. The traditional cultures of Italy and France, for example, are more similar to each other than either is to the cultures of the Maoris and Hawaiians. The psychological roots of culture also help explain why some bits of culture change and others stay put. Some collective practices have enormous inertia because they impose a high cost on the first individual who would try to change them. A switch from driving on the left to driving on the right could not begin with a daring nonconformist or a grass-roots movement but would have to be imposed from the top down (which is what happened in Sweden at 5 a. m. , Sunday, September 3, 1967).