The Nurture Assumption (book)

Judith Rich Harris The Nurture Assumption (1998) Harris attacks the assumption that we turn out the way we do because of our parents. It's not nurture by parents that determines our adult personality (and personal problems / successes), it's our peer group. She starts with a couple of obvious but unaddressed observations: 1) that children in fact live their lives with other children; and 2) that immigrant children adopt the language, dress and manners of their playmates, not their parents. (She has some wise things to say about this estrangement between immigrant parents and their children.)  On this foundation she builds a very persuasive case. Along the way she distinguishes between character (largely inborn), personality (largely acquired, and changeable), and the self (the result of socialisation.)
     Harris's theory is almost but not quite a theory of everything. She notes how the same-age peer-group is an effect of our modern civilisation, and that in earlier societies a child's peer group was multi-aged. The older kids pass on their culture to the younger ones in this case. In our case, the younger ones may as well be from different countries, they are so different from their older relatives and friends. (The Pokemon craze supports this: it's a 6-10 year old phenom, mostly.) She also notes that school success flows primarily from the values and attitudes of the peer group, not the parents. When a child lives in a homogeneous neighbourhood, where both parents and children are largely similar, the child will of course resemble its parents, not because parental culture is the molding force, but because the children's culture differs so little from that of their parents'. When the neighbourhood is culturally diverse, the children will adapt and create a culture of their own, and this may be radically different from that of their parents. Hence intergenerational conflict
     She does not ignore the effect of inheritance; in fact she claims that the investigators of inherited traits are the ones who produce the data that requires some other explanation(s) than the nurture assumption. And so on. Her theory is predictive. For example, twins raised apart should show more similarities when their peer groups are similar and fewer when they are different. This is borne out by the data. She claims that birth-order effects are real, but only within the family. IOW, people have different personalities in different social contexts. She does not deny the influence of parents, but notes that it is limited mostly to the family itself (ie, how the people get along as a family), in which parental influence competes with sibling influence; and for the rest it is indirect, in that the choice of where to live affects the peer-groups that will influence the child.
     I think her argument is plausible. Her smaller claim is that there is a lot more to human development than parental nurture; and she lists and explains the other influences. Her larger claim is that these other influences outweigh that of parents. I think she is right. The book is quite repetitious, since she builds her case from several different starting points. It could have done with some tables or graphs, or some appendices presenting the data. Nevertheless, this is an important book.  The nurture assumption is under attack from other quarters also. There is the danger that social scientists will create a new orthodoxy out of one or the other of the alternatives, however. **** (1999)
     Update 2012: It's now quite clear that nature vs nurture has always been a nonsensical dichotomy. Logic alone would dictate that conclusion: no observed trait can be wholly the product of either nature or nurture. When I first realised this, I thought the puzzle was how to assign proportionate influences to nature and nurture. Genetics has shown that this is a mistaken, or at least a misdirecting, question. Nature and nurture work together to produce any given trait or behaviour. The better question is how, not how much.