Indeed, the differences were not just unexplained but unmentionable, out of a fear that people would misinterpret the observation that some cultures were more technologically sophisticated than others as some kind of moral
judgment
that advanced societies were better than primitive ones.
Steven-Pinker-The-Blank-Slate 1
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). Other examples are laying down your weapons when hostile neighbors are armed to the teeth, abandoning the QWERTY keyboard layout, and pointing out that the emperor is not wearing any clothes. But traditional cultures can change, too, and more dramatically than most people realize. Preserving cultural diversity is considered a supreme virtue today, but the members of the diverse cultures don't always see it that way. People have wants and needs, and when cultures rub shoulders, people in one culture are bound to notice when their neighbors are satisfying those desires better than they are. When they do notice, history tells us, they shamelessly borrow whatever works best. Far from being self-preserving monoliths, cultures are porous and constantly in flux. Language, once again, is a clear example. Notwithstanding the perennial lamentations of purists and the sanctions of language academies, no language is ever spoken the way it was centuries before. Just compare contemporary English with the language of Shakespeare, or the language of Shakespeare with the language of Chaucer. Many other "traditional" practices are surprisingly recent. The ancestors of the Hasidic Jews did not wear black coats and fur- lined hats in Levantine deserts, nor did the Plains Indians ride horses before the arrival of the Europeans. National cuisines, too, have shallow roots. Potatoes in Ireland, paprika in Hungary, tomatoes in Italy, hot chile peppers in India and China, and cassava in Africa come from New World plants, and were brought to their "traditional" homes in the
? ? ? ? ? ? centuries after the arrival of Columbus in the Americas. 21
The idea that a culture is a tool for living can even explain the fact that first led Boas to argue the opposite, that a culture is an autonomous system of {67} ideas. The most obvious cultural difference on the planet is that some cultures are materially more successful than others. In past centuries, cultures from Europe and Asia decimated the cultures of Africa, the Americas, Australia, and rhe Pacific. Even within Europe and Asia the fortunes of cultures have varied widely, some developing expansive civilizations rich in art, science, and technology, others stuck in poverty and helpless to resist conquest. What allowed small groups of Spaniards to cross the Atlantic and defeat the great empires of the Incas and Aztecs, rather than the other way around? Why didn't African tribes colonize Europe instead of vice versa? The immediate answer is that the wealthy conquerors had better technology and a more complex political and economic organization. But that simply pushes back the question of why some cultures develop more complex ways of life than others.
Boas helped overthrow the bad racial science of the nineteenth century that attributed these disparities to differences in how far each race had biologically evolved. In its place his successors stipulated that behavior is determined by culture and that culture is autonomous from biology. 22 Unfortunately, that left the dramatic differences among cultures unexplained, as if they were random outcomes of the lottery in Babylon.
Indeed, the differences were not just unexplained but unmentionable, out of a fear that people would misinterpret the observation that some cultures were more technologically sophisticated than others as some kind of moral judgment that advanced societies were better than primitive ones. But no one can fail to notice that some cultures can accomplish things that all people want (like health and comfort) better than others. The dogma that cultures vary capriciously is a feeble refutation of any private opinion that some races have what it takes to develop science, technology, and government and others don't. But recently two scholars, working independently, have decisively shown that there is no need to invoke race to explain differences among cultures. Both arrived at that conclusion by eschewing the Standard Social Science Model, in which cultures are arbitrary symbol systems that exist apart from the minds of individual people. In his trilogy Race and Culture, Migrations and Cultures, and Conquests and Cultures, the economist Thomas Sowell explained his starting point for an analysis of cultural differences:
A culture is not a symbolic pattern, preserved like a butterfly in amber. Its place is not in a museum but in the practical activities of daily life, where it evolves under the stress of competing goals and other competing cultures. Cultures do not exist as simply static "differences" to be celebrated but compete with one another as better and worse ways of getting things done -- better and worse, not from the standpoint of some observer, but from the standpoint of the peoples themselves, as they cope and aspire amid the gritty realities of life. 23 {68}
The physiologist Jared Diamond is a proponent of ideas in evolutionary psychology and of consilience between the sciences and the humanities, particularly history. 24 In Guns, Germs, and Steel he rejected the standard assumption that history is just one damn thing after another and tried to explain the sweep of human history over tens of thousands of years in the context of human evolution and ecology. 25 Sowell and Diamond have made an authoritative case that the fates of human societies come neither from chance nor from race but from the human drive to adopt the innovations of others, combined with the vicissitudes of geography and ecology.
Diamond begins at the beginning. For most of human evolutionary history we lived as hunter-gatherers. The
trappings of civilization -- sedentary living, cities, a division of labor, government, professional armies, writing, metallurgy -- sprang from a recent development, farming, about ten thousand years ago. Farming depends on plants and animals that can be tamed and exploited, and only a few species are suited to it. They happened to be concentrated in a few parts of the world, including the Fertile Crescent, China, and Central and South America. The first civilizations arose in those regions.
From then on, geography was destiny. Diamond and Sowell point out that Eurasia, the world's largest landmass, is an enormous catchment area for local innovations. Traders, sojourners, and conquerors can collect them and spread them, and people living at the crossroads can concentrate them into a high-tech package. Also, Eurasia runs in an east- west direction, whereas Africa and the Americas run north-south. Crops and animals that are domesticated in one region can easily be spread to others along lines of latitude, which are also lines of similar climate. But they cannot
be spread as easily along lines of longitude, where a few hundred miles can spell the difference between temperate and tropical climates. Horses domesticated in the Asian steppes, for example, could make their way westward to Europe and eastward to China, but llamas and alpacas domesticated in the Andes never made it northward to Mexico, so the Mayan and Aztec civilizations were left without pack animals. And until recently the transportation of heavy goods over long distances (and with them traders and their ideas) was possible only by water. Europe and parts of Asia are blessed by a notchy, furrowed geography with many natural harbors and navigable rivers. Africa and Australia are not.
? ? ? ? ? ? ? So Eurasia conquered the world not because Eurasians are smarter but because they could best take advantage of the principle that many heads are better than one. The "culture" of any of the conquering nations of Europe, such as Britain, is in fact a greatest-hits collection of inventions assembled across thousands of miles and years. The collection is made up of cereal crops and alphabetic writing from the Middle East, gunpowder and paper from China, domesticated horses from Ukraine, and many others. But the necessarily insular cultures of Australia, Africa, and the Americas had to make do with a few {69} homegrown technologies, and as a result they were no match for their pluralistic conquerors. Even within Eurasia and (later) the Americas, cultures that were isolated by mountainous geography -- for example, in the Appalachians, the Balkans, and the Scottish highlands -- remained backward for centuries in comparison with the vast network of people around them.
The extreme case, Diamond points out, is Tasmania. The Tasmanians, who were nearly exterminated by Europeans in the nineteenth century, were the most technologically primitive people in recorded history. Unlike the Aborigines on the Australian mainland, the Tasmanians had no way of making tire, no boomerangs or spear throwers, no specialized stone tools, no axes with handles, no canoes, no sewing needles, and no ability to fish. Amazingly, the archaeological record shows that their ancestors from the Australian mainland had arrived with these technologies ten thousand years before. But then the land bridge connecting Tasmania to the mainland was submerged and the island was cut off from the rest of the world. Diamond speculates that any technology can be lost from a culture at some point in its history. Perhaps a raw material came to be in short supply and people stopped making the products that depended on it. Perhaps all the skilled artisans in a generation were killed by a freak storm. Perhaps some prehistoric Luddite or ayatollah imposed a taboo on the practice for one inane reason or another. Whenever this happens n a culture that rubs up against other ones, the lost technology can eventually be reacquired as the people clamor for the higher standard of living enjoyed by their neighbors. But in lonely Tasmania, people would have had to reinvent the proverbial wheel every time it was lost, and so their standard of living ratcheted downward.
The ultimate irony of the Standard Social Science Model is that it failed to accomplish the very goal that brought it into being: explaining the different fortunes of human societies without invoking race. The best explanation today is thoroughly cultural, but it depends on seeing a culture as a product of human desires rather than as a shaper of them. History and culture, then, can be grounded in psychology, which can be grounded in computation, neuroscience, genetics, and evolution. But this kind of talk sets off alarms in the minds of many nonscientists. They fear that consilience is a smokescreen for a hostile takeover of the humanities, arts, and social sciences by philistines in white coats. The richness of their subject matter would be dumbed down into a generic palaver about neurons, genes, and evolutionary urges. This scenario is often called "reductionism," and I will conclude the chapter by showing why consilience does not call for it.
Reductionism, like cholesterol, comes in good and bad forms. Bad reductionism -- also called "greedy reductionism" or "destructive reductionism" -- consists of trying to explain a phenomenon in terms of its smallest or simplest
{70} constituents. Greedy reductionism is not a straw man. I know several scientists who believe (or at least say to granting agencies) that we will make break-throughs in education, conflict resolution, and other social concerns by studying the biophysics of neural membranes or the molecular structure of the synapse. But greedy reductionism is far from the majority view, and it is easy to show why it is wrong. As the philosopher Hilary Putnam has pointed out, even the simple fact that a square peg won't fit into a round hole cannot be explained in terms of molecules and atoms but only at a higher level of analysis involving rigidity (regardless of what makes the peg rigid) and geometry. 26 And if anyone really thought that sociology or literature or history could be replaced by biology, why stop there? Biology could in turn be ground up into chemistry, and chemistry into physics, leaving one struggling to explain the causes of World War I in terms of electrons and quarks. Even if World War I consisted of nothing but a very, very large number of quarks in a very, very complicated pattern of motion, no insight is gained by describing it that way.
Good reductionism (also called hierarchical reductionism) consists not of replacing one field of knowledge with another but of connecting or unifying them. The building blocks used by one field are put under a microscope by another. The black boxes get opened; the promissory notes get cashed. A geographer might explain why the coastline of Africa fits into the coastline of the Americas by saying that the landmasses were once adjacent but sat on different plates, which drifted apart. The question of why the plates move gets passed on to the geologists, who appeal to an upwelling of magma that pushes them apart. As for how the magma got so hot, they call in the physicists to explain the reactions in the Earth's core and mantle. None of the scientists is dispensable. An isolated geographer would have to invoke magic to move the continents, and an isolated physicist could not have predicted the shape of South America.
So, too, for the bridge between biology and culture. The big thinkers in the sciences of human nature have been adamant that mental life has to be understood at several levels of analysis, not just the lowest one. The linguist Noam Chomsky, the computational neuroscientist David Marr, and the ethologist Niko Tinbergen have independently marked out a set of levels of analysis for understanding a faculty of the mind. These levels include its function (what
? ? ? it accomplishes in an ultimate, evolutionary sense); its real-time operation (how it works proximately, from moment to moment); how it is implemented in neural tissue; how it develops in the individual; and how it evolved in the species. 27 For example, language is based on a combinatorial grammar designed to communicate an unlimited number of thoughts. It is utilized by people in real time via an interplay of memory lookup and rule application. It is implemented in a network of regions in the center of the left cerebral hemisphere that must coordinate memory, planning, word meaning, and grammar. {71} It develops in the first three years of life in a sequence from babbling to words to word combinations, including errors in which rules maybe overapplied. It evolved through modifications of a vocal tract and brain circuitry that had other uses in earlier primates, because the modifications allowed our ancestors to prosper in a socially interconnected, knowledge-rich lifestyle. None of these levels can be replaced by any of the others, but none can be fully understood in isolation from the others.
Chomsky distinguishes all of these from yet another level of analysis (one that he himself has little use for but that other language scholars invoke). The vantage points I just mentioned treat language as an internal, individual entity, such as the knowledge of Canadian English that I possess in my head. But Language can also be understood as an external entity: the "English language" as a whole, with its fifteen-hundred-year history, its countless dialects and hybrids spanning the globe, its half a million words in the Oxford English Dictionary. An external language is an abstraction that pools the internal languages of hundreds of millions of people living in different places and times. It could not exist without the internal languages in the minds of real humans conversing with one another, but it cannot be reduced to what any of them knows either. For example, the statement "English has a larger vocabulary than Japanese" could be true even if no English speaker has a larger vocabulary than any Japanese speaker.
The English language was shaped by broad historical events that did not take place inside a single head. They include the Scandinavian and Norman invasions in medieval times, which infected it with non-Anglo-Saxon words; the Great Vowel Shift of the fifteenth century, which scrambled the pronunciation of the long vowels and left its spelling system an irregular mess; the expansion of the British Empire, which budded off a variety of Englishes (American, Australian, Singaporean); and the development of global electronic media, which may rehomogenize the language as we all read the same web pages and watch the same television shows.
At the same time, none of these forces can be understood without taking into account the thought processes of flesh- and-blood people. They include the Britons who reanalyzed French words when they absorbed them into English, the children who failed to remember irregular past-tense forms like writhe-wrothe and crow-crew and converted them into regular verbs, the aristocrats who affected fussy pronunciations to differentiate themselves from the rabble, the mumblers who swallowed consonants to leave us made and had (originally maked and haved), and the clever speakers who first converted I had the house built to I had built the house and inadvertently gave English its perfect tense. Language is re-created every generation as it passes through the minds of the humans who speak it. 28
External language is, of course, a fine example of culture, the province of {72} social scientists and scholars in the humanities. The way that language can be understood at some half-dozen connected levels of analysis, from the brain and evolution to the cognitive processes of individuals to vast cultural systems, shows how culture and biology may be connected. The possibilities for connections in other spheres of human knowledge are plentiful, and we will encounter them throughout the book. The moral sense can illuminate legal and ethical codes. The psychology of kinship helps us understand sociopolitical arrangements. The mentality of aggression helps to make sense of war and conflict resolution. Sex differences are relevant to gender politics. Human aesthetics and emotion can enlighten our understanding of the arts.
What is the payoff for connecting the social and cultural levels of analysis to the psychological and biological ones? It is the thrill of discoveries that could never be made within the boundaries of a single discipline, such as universals of beauty, the logic of language, and the components of the moral sense. And it is the uniquely satisfying understanding we have enjoyed from the unification of the other sciences -- the explanation of muscles as tiny magnetic ratchets, of flowers as lures for insects, of the rainbow as a splaying of wavelengths that ordinarily blend into white. It is the difference between stamp collecting and detective work, between slinging around jargon and offering insight, between saying that something just is and explaining why it had to be that way as opposed to some other way it could have been. In a talk-show parody in Monty Python's Flying Circus, an expert on dinosaurs trumpets her new theory of the brontosaurus: "All brontosauruses are thin at one end; much, much thicker in the middle; and then thin again at the far end. " We laugh because she has not explained her subject in terms of deeper principles -- she has not "reduced" it, in the good sense. Even the word understand -- literally, "stand under" -- alludes to descending to a deeper level of analysis.
Our understanding of life has only been enriched by the discovery that living flesh is composed of molecular clockwork rather than quivering protoplasm, or that birds soar by exploiting the laws of physics rather than defying them. In the same way, our understanding of ourselves and our cultures can only be enriched by the discovery that our minds are composed of intricate neural circuits for thinking, feeling, and learning rather than blank slates,
? ? ? ? amorphous blobs, or inscrutable ghosts.
<< {73} >> Chapter 5
The Slate's Last Stand
Human nature is a scientific topic, and as new facts come in, our conception of it will change. Sometimes the facts may show that a theory grants our minds too much innate structure. For example, perhaps our language faculties are equipped not with nouns, verbs, adjectives, and prepositions but only with a distinction between more nounlike and more verblike parts of speech. At other times a theory may turn out to have granted our minds too little innate structure. No current theory of personality can explain why both members of a pair of identical twins reared apart liked to keep rubber bands around their wrists and pretend to sneeze in crowded elevators.
Also up for grabs is exactly how our minds use the information coming in from the senses. Once our faculties for language and social interaction are up and running, some kinds of learning may consist of simply recording information for future use, like the name of a person or the content of a new piece of legislation. Others may be more like setting a dial, flipping a switch, or computing an average, where the apparatus is in place but a parameter is left open so the mind can track variation in the local environment. Still others may use the information provided by all normal environments, such as the presence of gravity or the statistics of colors and lines in the visual field, to tune up our sensorimotor systems. There are yet other ways that nature and nurture might interact, and many will blur the distinction between the two.
This book is based on the estimation that whatever the exact picture turns out to be, a universal complex human nature will be part of it. I think we have reason to believe that the mind is equipped with a battery of emotions, drives, and faculties for reasoning and communicating, and that they have a common logic across cultures, are difficult to erase or redesign from scratch, were shaped by natural selection acting over the course of human evolution, and owe some of their basic design (and some of their variation) to information in the genome. This general picture is meant to embrace a variety of theories, present and future, and a range of foreseeable scientific discoveries. {74}
But the picture does not embrace just any theory or discovery. Conceivably scientists might discover that there is insufficient information in the genome to specify any innate circuitry, or no known mechanism by which it could be wired into the brain. Or perhaps they will discover that brains are made out of general-purpose stuff that can soak up just about any pattern in the sensory input and organize itself to accomplish just about any goal. The former discovery would make innate organization impossible; the latter would make it unnecessary. Those discoveries would call into question the very concept of human nature. Unlike the moral and political objections to the concept of human nature (objections that I discuss in the rest of this book), these would be scientific objections. If such discoveries are on the horizon, I had better look at them carefully.
This chapter is about three scientific developments that are sometimes interpreted as undermining the possibility of a complex human nature. The first comes from the Human Genome Project. When the sequence of the human genome was published in 2001, geneticists were surprised that the number of genes was lower than they had predicted. The estimates hovered around 34,000 genes, which lies well outside the earlier range of 50,000 to 100,000. 1 Some editorialists concluded that the smaller gene count refuted any claim about innate talents or tendencies, because the slate is too small to contain much writing. Some even saw it as vindicating the concept of free will: the smaller the machine, the more room for a ghost.
The second challenge comes from the use of computer models of neural networks to explain cognitive processes. These artificial neural networks can often be quite good at learning statistical patterns in their input. Some modelers from the school of cognitive science called connectionism suggest that generic neural networks can account for all of human cognition, with little or no innate tailoring for particular faculties such as social reasoning or language. In Chapter 2 we met the founders of connectionism, David Rumelhart and James McClelland, who suggested that people are smarter than rats only because they have more associative cortex and because their environment contains a culture to organize it.
The third comes from the study of neural plasticity, which examines how the brain develops in the womb and early childhood and how it records experience as the animal learns. Neuroscientists have recently shown how the brain changes in response to learning, practice, and input from the senses. One spin on these discoveries may be called extreme plasticity. According to this slant, the cerebral cortex -- the convoluted gray matter responsible for perception, thinking, language, and memory -- is a protean substance that can be shaped almost limitlessly by the structure and demands of the environment. The blank slate becomes the plastic slate.
? ? ? ? ? ? ? ? Connectionism and extreme plasticity are popular among cognitive {75} scientists at the West Pole, who reject a completely blank slate but want to restrict innate organization to simple biases in attention and memory. Extreme plasticity also appeals to neuroscientists who wish to boost the importance of their field for education and social policy, and to entrepreneurs selling products to speed up infant development, cure learning disabilities, or slow down aging. Outside the sciences, all three developments have been welcomed by some scholars in the humanities who want to beat back the encroachments of biology. 2 The lean genome, connectionism, and extreme plasticity are the Blank Slate's last stand.
The point of this chapter is that these claims are not vindications of the doctrine of the Blank Slate but products of the Blank Slate. Many people (including a few scientists) have selectively read the evidence, sometimes in bizarre ways, to fit with a prior belief that the mind cannot possibly have any innate structure, or with simplistic notions of how innate structure, if it did exist, would be encoded in the genes and develop in the brain.
I should say at the outset that I find these latest-and-best blank-slate theories highly implausible -- indeed, barely coherent. Nothing comes out of nothing, and the complexity of the brain has to come from somewhere. It cannot come from the environment alone, because the whole point of having a brain is to accomplish certain goals, and the environment has no idea what those goals are. A given environment can accommodate organisms that build dams, migrate by the stars, trill and twitter to impress the females, scent-mark trees, write sonnets, and so on. To one species, a snatch of human speech is a warning to flee; to another, it is an interesting new sound to incorporate into its own vocal repertoire; to a third, it is grist for grammatical analysis. Information in the world doesn't tell you what to do with it.
Also, brain tissue is not some genie that can grant its owner any power that would come in handy. It is a physical mechanism, an arrangement of matter that converts inputs to outputs in particular ways. The idea that a single generic substance can see in depth, control the hands, attract a mate, bring up children, elude predators, outsmart prey, and so on, without some degree of specialization, is not credible. Saying that the brain solves these problems because of its "plasticity" is not much better than saying it solves them by magic. Still, in this chapter I will examine the latest scientific objections to human nature carefully. Each of the discoveries is important on its own terms, even if it does not support the extravagant conclusions that have been drawn. And once the last supports for the Blank Slate have been evaluated, I can properly sum up the scientific case for the alternative.
The human genome is often seen as the essence of our species, so it is not surprising that when its sequence was announced in 2001 commentators rushed to give it the correct interpretation for human affairs. Craig Venter, {76} whose company had competed with a public consortium in the race to sequence the genome, said at a press conference that the smaller-than-expected gene count shows that "we simply do not have enough genes for this idea of biological determinism to be right. The wonderful diversity of the human species is not hard-wired in our genetic code. Our environments are critical. " In the United Kingdom, The Guardian headlined its story, "Revealed: The Secret of Human Behaviour. Environment, Not Genes, Key to Our Acts. "3 An editorial in another British newspaper concluded that "we are more free, it seems, than we had realized. " Moreover, the finding "offers comfort for the left, with its belief in the potential of all, however deprived their background. But it is damning for the right, with its fondness for ruling classes and original sin. "4
All this from the number 34,000! Which leads to the question, What number of genes would have proven that the diversity of our species was wired into our genetic code, or that we are less free than we had realized, or that the political right is right and the left is wrong? 50,000? 150,000? Conversely, if it turned out that we had only 20,000 genes, would that have made us even freer, or the environment even more important, or the political left even more comfortable? The fact is that no one knows what these numbers mean. No one has the slightest idea how many genes it would take to build a system of hard-wired modules, or a general-purpose learning program, or anything in between -- to say nothing of original sin or the superiority of the ruling class. In our current state of ignorance of how the genes build a brain, the number of genes in the human genome is just a number.
If you don't believe this, consider the roundworm Caenorhabditis elegans, which has about 18,000 genes. By the logic of the genome editorialists, it should be twice as free, be twice as diverse, and have twice as much potential as a human being. In fact, it is a microscopic worm composed of 959 cells grown by a rigid genetic program, with a nervous system consisting of exactly 302 neurons in a fixed wiring diagram.
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). Other examples are laying down your weapons when hostile neighbors are armed to the teeth, abandoning the QWERTY keyboard layout, and pointing out that the emperor is not wearing any clothes. But traditional cultures can change, too, and more dramatically than most people realize. Preserving cultural diversity is considered a supreme virtue today, but the members of the diverse cultures don't always see it that way. People have wants and needs, and when cultures rub shoulders, people in one culture are bound to notice when their neighbors are satisfying those desires better than they are. When they do notice, history tells us, they shamelessly borrow whatever works best. Far from being self-preserving monoliths, cultures are porous and constantly in flux. Language, once again, is a clear example. Notwithstanding the perennial lamentations of purists and the sanctions of language academies, no language is ever spoken the way it was centuries before. Just compare contemporary English with the language of Shakespeare, or the language of Shakespeare with the language of Chaucer. Many other "traditional" practices are surprisingly recent. The ancestors of the Hasidic Jews did not wear black coats and fur- lined hats in Levantine deserts, nor did the Plains Indians ride horses before the arrival of the Europeans. National cuisines, too, have shallow roots. Potatoes in Ireland, paprika in Hungary, tomatoes in Italy, hot chile peppers in India and China, and cassava in Africa come from New World plants, and were brought to their "traditional" homes in the
? ? ? ? ? ? centuries after the arrival of Columbus in the Americas. 21
The idea that a culture is a tool for living can even explain the fact that first led Boas to argue the opposite, that a culture is an autonomous system of {67} ideas. The most obvious cultural difference on the planet is that some cultures are materially more successful than others. In past centuries, cultures from Europe and Asia decimated the cultures of Africa, the Americas, Australia, and rhe Pacific. Even within Europe and Asia the fortunes of cultures have varied widely, some developing expansive civilizations rich in art, science, and technology, others stuck in poverty and helpless to resist conquest. What allowed small groups of Spaniards to cross the Atlantic and defeat the great empires of the Incas and Aztecs, rather than the other way around? Why didn't African tribes colonize Europe instead of vice versa? The immediate answer is that the wealthy conquerors had better technology and a more complex political and economic organization. But that simply pushes back the question of why some cultures develop more complex ways of life than others.
Boas helped overthrow the bad racial science of the nineteenth century that attributed these disparities to differences in how far each race had biologically evolved. In its place his successors stipulated that behavior is determined by culture and that culture is autonomous from biology. 22 Unfortunately, that left the dramatic differences among cultures unexplained, as if they were random outcomes of the lottery in Babylon.
Indeed, the differences were not just unexplained but unmentionable, out of a fear that people would misinterpret the observation that some cultures were more technologically sophisticated than others as some kind of moral judgment that advanced societies were better than primitive ones. But no one can fail to notice that some cultures can accomplish things that all people want (like health and comfort) better than others. The dogma that cultures vary capriciously is a feeble refutation of any private opinion that some races have what it takes to develop science, technology, and government and others don't. But recently two scholars, working independently, have decisively shown that there is no need to invoke race to explain differences among cultures. Both arrived at that conclusion by eschewing the Standard Social Science Model, in which cultures are arbitrary symbol systems that exist apart from the minds of individual people. In his trilogy Race and Culture, Migrations and Cultures, and Conquests and Cultures, the economist Thomas Sowell explained his starting point for an analysis of cultural differences:
A culture is not a symbolic pattern, preserved like a butterfly in amber. Its place is not in a museum but in the practical activities of daily life, where it evolves under the stress of competing goals and other competing cultures. Cultures do not exist as simply static "differences" to be celebrated but compete with one another as better and worse ways of getting things done -- better and worse, not from the standpoint of some observer, but from the standpoint of the peoples themselves, as they cope and aspire amid the gritty realities of life. 23 {68}
The physiologist Jared Diamond is a proponent of ideas in evolutionary psychology and of consilience between the sciences and the humanities, particularly history. 24 In Guns, Germs, and Steel he rejected the standard assumption that history is just one damn thing after another and tried to explain the sweep of human history over tens of thousands of years in the context of human evolution and ecology. 25 Sowell and Diamond have made an authoritative case that the fates of human societies come neither from chance nor from race but from the human drive to adopt the innovations of others, combined with the vicissitudes of geography and ecology.
Diamond begins at the beginning. For most of human evolutionary history we lived as hunter-gatherers. The
trappings of civilization -- sedentary living, cities, a division of labor, government, professional armies, writing, metallurgy -- sprang from a recent development, farming, about ten thousand years ago. Farming depends on plants and animals that can be tamed and exploited, and only a few species are suited to it. They happened to be concentrated in a few parts of the world, including the Fertile Crescent, China, and Central and South America. The first civilizations arose in those regions.
From then on, geography was destiny. Diamond and Sowell point out that Eurasia, the world's largest landmass, is an enormous catchment area for local innovations. Traders, sojourners, and conquerors can collect them and spread them, and people living at the crossroads can concentrate them into a high-tech package. Also, Eurasia runs in an east- west direction, whereas Africa and the Americas run north-south. Crops and animals that are domesticated in one region can easily be spread to others along lines of latitude, which are also lines of similar climate. But they cannot
be spread as easily along lines of longitude, where a few hundred miles can spell the difference between temperate and tropical climates. Horses domesticated in the Asian steppes, for example, could make their way westward to Europe and eastward to China, but llamas and alpacas domesticated in the Andes never made it northward to Mexico, so the Mayan and Aztec civilizations were left without pack animals. And until recently the transportation of heavy goods over long distances (and with them traders and their ideas) was possible only by water. Europe and parts of Asia are blessed by a notchy, furrowed geography with many natural harbors and navigable rivers. Africa and Australia are not.
? ? ? ? ? ? ? So Eurasia conquered the world not because Eurasians are smarter but because they could best take advantage of the principle that many heads are better than one. The "culture" of any of the conquering nations of Europe, such as Britain, is in fact a greatest-hits collection of inventions assembled across thousands of miles and years. The collection is made up of cereal crops and alphabetic writing from the Middle East, gunpowder and paper from China, domesticated horses from Ukraine, and many others. But the necessarily insular cultures of Australia, Africa, and the Americas had to make do with a few {69} homegrown technologies, and as a result they were no match for their pluralistic conquerors. Even within Eurasia and (later) the Americas, cultures that were isolated by mountainous geography -- for example, in the Appalachians, the Balkans, and the Scottish highlands -- remained backward for centuries in comparison with the vast network of people around them.
The extreme case, Diamond points out, is Tasmania. The Tasmanians, who were nearly exterminated by Europeans in the nineteenth century, were the most technologically primitive people in recorded history. Unlike the Aborigines on the Australian mainland, the Tasmanians had no way of making tire, no boomerangs or spear throwers, no specialized stone tools, no axes with handles, no canoes, no sewing needles, and no ability to fish. Amazingly, the archaeological record shows that their ancestors from the Australian mainland had arrived with these technologies ten thousand years before. But then the land bridge connecting Tasmania to the mainland was submerged and the island was cut off from the rest of the world. Diamond speculates that any technology can be lost from a culture at some point in its history. Perhaps a raw material came to be in short supply and people stopped making the products that depended on it. Perhaps all the skilled artisans in a generation were killed by a freak storm. Perhaps some prehistoric Luddite or ayatollah imposed a taboo on the practice for one inane reason or another. Whenever this happens n a culture that rubs up against other ones, the lost technology can eventually be reacquired as the people clamor for the higher standard of living enjoyed by their neighbors. But in lonely Tasmania, people would have had to reinvent the proverbial wheel every time it was lost, and so their standard of living ratcheted downward.
The ultimate irony of the Standard Social Science Model is that it failed to accomplish the very goal that brought it into being: explaining the different fortunes of human societies without invoking race. The best explanation today is thoroughly cultural, but it depends on seeing a culture as a product of human desires rather than as a shaper of them. History and culture, then, can be grounded in psychology, which can be grounded in computation, neuroscience, genetics, and evolution. But this kind of talk sets off alarms in the minds of many nonscientists. They fear that consilience is a smokescreen for a hostile takeover of the humanities, arts, and social sciences by philistines in white coats. The richness of their subject matter would be dumbed down into a generic palaver about neurons, genes, and evolutionary urges. This scenario is often called "reductionism," and I will conclude the chapter by showing why consilience does not call for it.
Reductionism, like cholesterol, comes in good and bad forms. Bad reductionism -- also called "greedy reductionism" or "destructive reductionism" -- consists of trying to explain a phenomenon in terms of its smallest or simplest
{70} constituents. Greedy reductionism is not a straw man. I know several scientists who believe (or at least say to granting agencies) that we will make break-throughs in education, conflict resolution, and other social concerns by studying the biophysics of neural membranes or the molecular structure of the synapse. But greedy reductionism is far from the majority view, and it is easy to show why it is wrong. As the philosopher Hilary Putnam has pointed out, even the simple fact that a square peg won't fit into a round hole cannot be explained in terms of molecules and atoms but only at a higher level of analysis involving rigidity (regardless of what makes the peg rigid) and geometry. 26 And if anyone really thought that sociology or literature or history could be replaced by biology, why stop there? Biology could in turn be ground up into chemistry, and chemistry into physics, leaving one struggling to explain the causes of World War I in terms of electrons and quarks. Even if World War I consisted of nothing but a very, very large number of quarks in a very, very complicated pattern of motion, no insight is gained by describing it that way.
Good reductionism (also called hierarchical reductionism) consists not of replacing one field of knowledge with another but of connecting or unifying them. The building blocks used by one field are put under a microscope by another. The black boxes get opened; the promissory notes get cashed. A geographer might explain why the coastline of Africa fits into the coastline of the Americas by saying that the landmasses were once adjacent but sat on different plates, which drifted apart. The question of why the plates move gets passed on to the geologists, who appeal to an upwelling of magma that pushes them apart. As for how the magma got so hot, they call in the physicists to explain the reactions in the Earth's core and mantle. None of the scientists is dispensable. An isolated geographer would have to invoke magic to move the continents, and an isolated physicist could not have predicted the shape of South America.
So, too, for the bridge between biology and culture. The big thinkers in the sciences of human nature have been adamant that mental life has to be understood at several levels of analysis, not just the lowest one. The linguist Noam Chomsky, the computational neuroscientist David Marr, and the ethologist Niko Tinbergen have independently marked out a set of levels of analysis for understanding a faculty of the mind. These levels include its function (what
? ? ? it accomplishes in an ultimate, evolutionary sense); its real-time operation (how it works proximately, from moment to moment); how it is implemented in neural tissue; how it develops in the individual; and how it evolved in the species. 27 For example, language is based on a combinatorial grammar designed to communicate an unlimited number of thoughts. It is utilized by people in real time via an interplay of memory lookup and rule application. It is implemented in a network of regions in the center of the left cerebral hemisphere that must coordinate memory, planning, word meaning, and grammar. {71} It develops in the first three years of life in a sequence from babbling to words to word combinations, including errors in which rules maybe overapplied. It evolved through modifications of a vocal tract and brain circuitry that had other uses in earlier primates, because the modifications allowed our ancestors to prosper in a socially interconnected, knowledge-rich lifestyle. None of these levels can be replaced by any of the others, but none can be fully understood in isolation from the others.
Chomsky distinguishes all of these from yet another level of analysis (one that he himself has little use for but that other language scholars invoke). The vantage points I just mentioned treat language as an internal, individual entity, such as the knowledge of Canadian English that I possess in my head. But Language can also be understood as an external entity: the "English language" as a whole, with its fifteen-hundred-year history, its countless dialects and hybrids spanning the globe, its half a million words in the Oxford English Dictionary. An external language is an abstraction that pools the internal languages of hundreds of millions of people living in different places and times. It could not exist without the internal languages in the minds of real humans conversing with one another, but it cannot be reduced to what any of them knows either. For example, the statement "English has a larger vocabulary than Japanese" could be true even if no English speaker has a larger vocabulary than any Japanese speaker.
The English language was shaped by broad historical events that did not take place inside a single head. They include the Scandinavian and Norman invasions in medieval times, which infected it with non-Anglo-Saxon words; the Great Vowel Shift of the fifteenth century, which scrambled the pronunciation of the long vowels and left its spelling system an irregular mess; the expansion of the British Empire, which budded off a variety of Englishes (American, Australian, Singaporean); and the development of global electronic media, which may rehomogenize the language as we all read the same web pages and watch the same television shows.
At the same time, none of these forces can be understood without taking into account the thought processes of flesh- and-blood people. They include the Britons who reanalyzed French words when they absorbed them into English, the children who failed to remember irregular past-tense forms like writhe-wrothe and crow-crew and converted them into regular verbs, the aristocrats who affected fussy pronunciations to differentiate themselves from the rabble, the mumblers who swallowed consonants to leave us made and had (originally maked and haved), and the clever speakers who first converted I had the house built to I had built the house and inadvertently gave English its perfect tense. Language is re-created every generation as it passes through the minds of the humans who speak it. 28
External language is, of course, a fine example of culture, the province of {72} social scientists and scholars in the humanities. The way that language can be understood at some half-dozen connected levels of analysis, from the brain and evolution to the cognitive processes of individuals to vast cultural systems, shows how culture and biology may be connected. The possibilities for connections in other spheres of human knowledge are plentiful, and we will encounter them throughout the book. The moral sense can illuminate legal and ethical codes. The psychology of kinship helps us understand sociopolitical arrangements. The mentality of aggression helps to make sense of war and conflict resolution. Sex differences are relevant to gender politics. Human aesthetics and emotion can enlighten our understanding of the arts.
What is the payoff for connecting the social and cultural levels of analysis to the psychological and biological ones? It is the thrill of discoveries that could never be made within the boundaries of a single discipline, such as universals of beauty, the logic of language, and the components of the moral sense. And it is the uniquely satisfying understanding we have enjoyed from the unification of the other sciences -- the explanation of muscles as tiny magnetic ratchets, of flowers as lures for insects, of the rainbow as a splaying of wavelengths that ordinarily blend into white. It is the difference between stamp collecting and detective work, between slinging around jargon and offering insight, between saying that something just is and explaining why it had to be that way as opposed to some other way it could have been. In a talk-show parody in Monty Python's Flying Circus, an expert on dinosaurs trumpets her new theory of the brontosaurus: "All brontosauruses are thin at one end; much, much thicker in the middle; and then thin again at the far end. " We laugh because she has not explained her subject in terms of deeper principles -- she has not "reduced" it, in the good sense. Even the word understand -- literally, "stand under" -- alludes to descending to a deeper level of analysis.
Our understanding of life has only been enriched by the discovery that living flesh is composed of molecular clockwork rather than quivering protoplasm, or that birds soar by exploiting the laws of physics rather than defying them. In the same way, our understanding of ourselves and our cultures can only be enriched by the discovery that our minds are composed of intricate neural circuits for thinking, feeling, and learning rather than blank slates,
? ? ? ? amorphous blobs, or inscrutable ghosts.
<< {73} >> Chapter 5
The Slate's Last Stand
Human nature is a scientific topic, and as new facts come in, our conception of it will change. Sometimes the facts may show that a theory grants our minds too much innate structure. For example, perhaps our language faculties are equipped not with nouns, verbs, adjectives, and prepositions but only with a distinction between more nounlike and more verblike parts of speech. At other times a theory may turn out to have granted our minds too little innate structure. No current theory of personality can explain why both members of a pair of identical twins reared apart liked to keep rubber bands around their wrists and pretend to sneeze in crowded elevators.
Also up for grabs is exactly how our minds use the information coming in from the senses. Once our faculties for language and social interaction are up and running, some kinds of learning may consist of simply recording information for future use, like the name of a person or the content of a new piece of legislation. Others may be more like setting a dial, flipping a switch, or computing an average, where the apparatus is in place but a parameter is left open so the mind can track variation in the local environment. Still others may use the information provided by all normal environments, such as the presence of gravity or the statistics of colors and lines in the visual field, to tune up our sensorimotor systems. There are yet other ways that nature and nurture might interact, and many will blur the distinction between the two.
This book is based on the estimation that whatever the exact picture turns out to be, a universal complex human nature will be part of it. I think we have reason to believe that the mind is equipped with a battery of emotions, drives, and faculties for reasoning and communicating, and that they have a common logic across cultures, are difficult to erase or redesign from scratch, were shaped by natural selection acting over the course of human evolution, and owe some of their basic design (and some of their variation) to information in the genome. This general picture is meant to embrace a variety of theories, present and future, and a range of foreseeable scientific discoveries. {74}
But the picture does not embrace just any theory or discovery. Conceivably scientists might discover that there is insufficient information in the genome to specify any innate circuitry, or no known mechanism by which it could be wired into the brain. Or perhaps they will discover that brains are made out of general-purpose stuff that can soak up just about any pattern in the sensory input and organize itself to accomplish just about any goal. The former discovery would make innate organization impossible; the latter would make it unnecessary. Those discoveries would call into question the very concept of human nature. Unlike the moral and political objections to the concept of human nature (objections that I discuss in the rest of this book), these would be scientific objections. If such discoveries are on the horizon, I had better look at them carefully.
This chapter is about three scientific developments that are sometimes interpreted as undermining the possibility of a complex human nature. The first comes from the Human Genome Project. When the sequence of the human genome was published in 2001, geneticists were surprised that the number of genes was lower than they had predicted. The estimates hovered around 34,000 genes, which lies well outside the earlier range of 50,000 to 100,000. 1 Some editorialists concluded that the smaller gene count refuted any claim about innate talents or tendencies, because the slate is too small to contain much writing. Some even saw it as vindicating the concept of free will: the smaller the machine, the more room for a ghost.
The second challenge comes from the use of computer models of neural networks to explain cognitive processes. These artificial neural networks can often be quite good at learning statistical patterns in their input. Some modelers from the school of cognitive science called connectionism suggest that generic neural networks can account for all of human cognition, with little or no innate tailoring for particular faculties such as social reasoning or language. In Chapter 2 we met the founders of connectionism, David Rumelhart and James McClelland, who suggested that people are smarter than rats only because they have more associative cortex and because their environment contains a culture to organize it.
The third comes from the study of neural plasticity, which examines how the brain develops in the womb and early childhood and how it records experience as the animal learns. Neuroscientists have recently shown how the brain changes in response to learning, practice, and input from the senses. One spin on these discoveries may be called extreme plasticity. According to this slant, the cerebral cortex -- the convoluted gray matter responsible for perception, thinking, language, and memory -- is a protean substance that can be shaped almost limitlessly by the structure and demands of the environment. The blank slate becomes the plastic slate.
? ? ? ? ? ? ? ? Connectionism and extreme plasticity are popular among cognitive {75} scientists at the West Pole, who reject a completely blank slate but want to restrict innate organization to simple biases in attention and memory. Extreme plasticity also appeals to neuroscientists who wish to boost the importance of their field for education and social policy, and to entrepreneurs selling products to speed up infant development, cure learning disabilities, or slow down aging. Outside the sciences, all three developments have been welcomed by some scholars in the humanities who want to beat back the encroachments of biology. 2 The lean genome, connectionism, and extreme plasticity are the Blank Slate's last stand.
The point of this chapter is that these claims are not vindications of the doctrine of the Blank Slate but products of the Blank Slate. Many people (including a few scientists) have selectively read the evidence, sometimes in bizarre ways, to fit with a prior belief that the mind cannot possibly have any innate structure, or with simplistic notions of how innate structure, if it did exist, would be encoded in the genes and develop in the brain.
I should say at the outset that I find these latest-and-best blank-slate theories highly implausible -- indeed, barely coherent. Nothing comes out of nothing, and the complexity of the brain has to come from somewhere. It cannot come from the environment alone, because the whole point of having a brain is to accomplish certain goals, and the environment has no idea what those goals are. A given environment can accommodate organisms that build dams, migrate by the stars, trill and twitter to impress the females, scent-mark trees, write sonnets, and so on. To one species, a snatch of human speech is a warning to flee; to another, it is an interesting new sound to incorporate into its own vocal repertoire; to a third, it is grist for grammatical analysis. Information in the world doesn't tell you what to do with it.
Also, brain tissue is not some genie that can grant its owner any power that would come in handy. It is a physical mechanism, an arrangement of matter that converts inputs to outputs in particular ways. The idea that a single generic substance can see in depth, control the hands, attract a mate, bring up children, elude predators, outsmart prey, and so on, without some degree of specialization, is not credible. Saying that the brain solves these problems because of its "plasticity" is not much better than saying it solves them by magic. Still, in this chapter I will examine the latest scientific objections to human nature carefully. Each of the discoveries is important on its own terms, even if it does not support the extravagant conclusions that have been drawn. And once the last supports for the Blank Slate have been evaluated, I can properly sum up the scientific case for the alternative.
The human genome is often seen as the essence of our species, so it is not surprising that when its sequence was announced in 2001 commentators rushed to give it the correct interpretation for human affairs. Craig Venter, {76} whose company had competed with a public consortium in the race to sequence the genome, said at a press conference that the smaller-than-expected gene count shows that "we simply do not have enough genes for this idea of biological determinism to be right. The wonderful diversity of the human species is not hard-wired in our genetic code. Our environments are critical. " In the United Kingdom, The Guardian headlined its story, "Revealed: The Secret of Human Behaviour. Environment, Not Genes, Key to Our Acts. "3 An editorial in another British newspaper concluded that "we are more free, it seems, than we had realized. " Moreover, the finding "offers comfort for the left, with its belief in the potential of all, however deprived their background. But it is damning for the right, with its fondness for ruling classes and original sin. "4
All this from the number 34,000! Which leads to the question, What number of genes would have proven that the diversity of our species was wired into our genetic code, or that we are less free than we had realized, or that the political right is right and the left is wrong? 50,000? 150,000? Conversely, if it turned out that we had only 20,000 genes, would that have made us even freer, or the environment even more important, or the political left even more comfortable? The fact is that no one knows what these numbers mean. No one has the slightest idea how many genes it would take to build a system of hard-wired modules, or a general-purpose learning program, or anything in between -- to say nothing of original sin or the superiority of the ruling class. In our current state of ignorance of how the genes build a brain, the number of genes in the human genome is just a number.
If you don't believe this, consider the roundworm Caenorhabditis elegans, which has about 18,000 genes. By the logic of the genome editorialists, it should be twice as free, be twice as diverse, and have twice as much potential as a human being. In fact, it is a microscopic worm composed of 959 cells grown by a rigid genetic program, with a nervous system consisting of exactly 302 neurons in a fixed wiring diagram.
