Nobody doubts that genes can shape anatomy. The idea that they also shape behaviour takes a lot more swallowing. Yet I hope to persuade you that on chromosome 7 there lies a gene that plays an important part in equipping human beings with an instinct, and an instinct, moreover, that lies at the heart of all human culture.
Instinct is a word applied
these are instincts. Human beings do not have to rely on instinct; they learn instead; they are creative, cultural, conscious creatures.
Everything they do is the product of free will, giant brains and brainwashing parents.
So goes the conventional wisdom that has dominated psychology and all other social sciences in the twentieth century. To think otherwise, to believe in innate human behaviour, is to fall into the trap of determinism, and to condemn individual people to a heartless 9 2 G E N O M E
fate written in their genes before they were born. No matter that the social sciences set about reinventing much more alarming forms of determinism to take the place of the genetic form: the parental determinism of Freud; the socio-economic determinism of Marx; the political determinism of Lenin; the peer-pressure cultural determinism of Franz Boas and Margaret Mead; the stimulus—response determinism of John Watson and B. F. Skinner; the linguistic determinism of Edward Sapir and Benjamin Whorf. In one of the great diversions of all time, for nearly a century social scientists managed to persuade thinkers of many kinds that biological causality was determinism while environmental causality preserved free will; and that animals had instincts, but human beings did not.
Between 1950 and 1990 the edifice of environmental determinism came tumbling down. Freudian theory fell the moment lithium first cured a manic depressive, where twenty years of psychoanalysis had failed. (In 1995a woman sued her former therapist on the grounds that three weeks on Prozac had achieved more than three years of therapy.) Marxism fell when the Berlin wall was built, though it took until the wall came down before some people realised that subservience to an all-powerful state could not be made enjoyable however much propaganda accompanied it. Cultural determinism fell when Margaret Mead's conclusions (that adolescent behaviour was infinitely malleable by culture) were discovered by Derek Freeman to be based on a combination of wishful prejudice, poor data collection and adolescent prank-playing by her informants. Behaviourism fell with a famous 1950s experiment in Wisconsin in which orphan baby monkeys became emotionally attached to cloth models of their mothers even when fed only from wire models, thus refusing to obey the theory that we mammals can be conditioned to prefer the feel of anything that gives us food — a preference for soft mothers is probably innate.1
In linguistics, the first crack in the edifice was a book by Noam Chomsky,
which had been described by Darwin as an 'instinctive tendency to acquire an art'. The early psychologist William James, brother of the novelist Henry, was a fervent protagonist of the view that human behaviour showed evidence of more separate instincts than animals, not fewer. But his ideas had been ignored for most of the twentieth century. Chomsky brought them back to life.
By studying the way human beings speak, Chomsky concluded that there were underlying similarities to all languages that bore witness to a universal human grammar. We all know how to use it, though we are rarely conscious of that ability. This must mean that part of the human brain comes equipped by its genes with a specialised ability to learn language. Plainly, the vocabulary could not be innate, or we would all speak one, unvarying language. But perhaps a child, as it acquired the vocabulary of its native society, slotted those words into a set of innate mental rules. Chomsky's evidence for this notion was linguistic: he found regularities in the way we spoke that were never taught by parents and could not be inferred from the examples of everyday speech without great difficulty. For example, in English, to make a sentence into a question we bring the main verb to the front of the statement. But how do we know which verb to bring? Consider the sentence, 'A unicorn that is eating a flower is in the garden.' You can turn that sentence into a question by moving the second 'is' to the front: 'Is a unicorn that is eating a flower in the garden?' But you make no sense if you move the first 'is': 'Is a unicorn that eating a flower is in the garden?' The difference is that the first 'is' is part of a noun phrase, buried in the mental image conjured by not just any unicorn, but any unicorn that is eating a flower. Yet four-year-olds can comfortably use this rule, never having been taught about noun phrases. They just seem to know the rule. And they know it without ever having used or heard the phrase 'a unicorn that is eating a flower' before. That is the beauty of language - almost every statement we make is a novel combination of words.
Chomsky's conjecture has been brilliantly vindicated in the succeeding decades by lines of evidence from many different disciplines.
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All converge upon the conclusion that to learn a human language requires, in the words of the psycho-linguist Steven Pinker, a human language instinct. Pinker (who has been called the first linguist capable of writing readable prose) persuasively gathered the strands of evidence for the innateness of language skills. There is first the universality of language. All human people speak languages of comparable grammatical complexity, even those isolated in the highlands of New Guinea since the Stone Age. All people are as consistent and careful in following implicit grammatical rules, even those without education and who speak what are patronisingly thought to be 'slang'
dialects. The rules of inner-city black Ebonics are just as rational as the rules of the Queen's English. To prefer one to another is mere prejudice. For example, to use double negatives ('Don't nobody do this to me . . .') is considered proper in French, but slang in English.
The rule is just as consistently followed in each.
Second, if these rules were learnt by imitation like the vocabulary, then why would four-year-olds who have been happily using the word 'went' for a year or so, suddenly start saying 'goed'? The truth is that although we must teach our children to read and write —
skills for which there is no specialised instinct — they learn to speak by themselves at a much younger age with the least of help from us. No parent uses the word 'goed', yet most children do at some time. No parent explains that the word 'cup' refers to all cup-like objects, not this one particular cup, nor just its handle, nor the material from which it is made, nor the action of pointing to a cup, nor the abstract concept of cupness, nor the size or temperature of cups. A computer that was required to learn language would have to be laboriously equipped with a program that ignored all these foolish options — with an instinct, in other words. Children come pre-programmed, innately constrained to make only certain kinds of guess.
But the most startling evidence for a language instinct comes from a series of natural experiments in which children imposed grammatical rules upon languages that lacked them. In the most famous case, studied by Derek Bickerton, a group of foreign labour-ers brought together on Hawaii in the nineteenth century developed I N S T I N C T 9 5
a pidgin language - a mixture of words and phrases whereby they could communicate with each other. Like
