She has a twofold argument. First, that studies which purport to show parental effects on children’s personalities either fail to tease out how much is shared genes and how much is parental-child interaction independent of genes or do not capture anything that cannot be explained by shared genes. (Hereditary regularly shows up as explaining about 50% of variation between individuals, p.307.) Second, that group salience—the power of group-forming and identification, particularly in peer groups—is much more powerful in forming the personalities and perspectives of children than anything parents typically do. The authority of folk you-see-as-like-you is much more powerful than that of folk you-see-as-different.
Harris does mount a powerful case that folk have been far too ready to blame parents for just about everything based on an unexamined nurture assumption (you are largely the result of how your parents raised you). Her points about the power of peer groups are also powerfully argued and empirically supported. (E.g. picking up or losing accents, taking on local culture.) In particular, her discussion of teaching and classroom dynamics is one of those pieces of writing that should be read by every teacher. And I take her point that children also have an effect on parents and they have characteristics that affect how people treat them.
(Johnny comes from a broken home.
Johnny would be enough to break any home.)
Having, I thought, worked out a few things about my upbringing and its effect on me, I found reading The Nurture Assumption confronting. But productive, because it did make me think much more about peer group effects in growing up. It was even somewhat liberating, since it shook up what was beginning to be another form of assumed helplessness.
Yet, I am not fully persuaded. I think my parents had little effect on my personality (point to Harris). But it seems clear to me that they had a powerful effect on particular beliefs and patterns of behaviour. Harris indeed concedes that parents can set up patterns of behaviour that one is very likely to fall into again if one enters a similar situation later in life. She just argues that they stop once one is no longer in that similar situation.
Harris’s argument is that, essentially, parents only have an effect in areas where they have no competition. So things which are “in the home”, at least as far as the peer group are concerned—cooking habits, religion, politics—they can have a major effect on (p.330). But the minute the peer group gets to work, Harris argues, parents are powerless.
Note, she does not think what parents do does not matter. They have great potential to make their children unhappy, and that matters. If they turn the family into a group and act as leader of it, they can also have an enduring effect (Pp332ff).
Her argument about peer groups is essentially an argument about identification—children don’t see themselves as being parent-like but they do see themselves as being children-like, so other children set the pace in interactions and absorption of information. Yet how and where a child identifies with will vary from case to case, so the ambit of peer groups will vary from case to case.
Also, it seems unlikely that interactions with parents as babies and toddlers is irrelevant in establishing patterns which then feed into interactions with peers. Her point about the difficult in separating out parent-child interactions from parent-child genetic sharing seems to also apply about parent-or-peer interaction effects, given that parents get several years of “first go” at a rapidly developing and-at-its-most-malleable small child before peers get their go.
She is also not even in her treatment of variation. Variation in siblings is treated as an argument against parental influence (any features of the environment that are shared by two children growing up in the same home are pretty much ruled out as important influences on what they will be like as grownups p.307). Yet both variation and similarity in peer group experience is treated as causally crucial.
A warning bell for me was thinking about homosexuality. Harris notes (P.51) that studies have failed to show significant differences between the children of opposite-sex and same-sex couples—which she includes as part of a general argument that variances in child-rearing arrangements do not seem to generate congruent variances in children. (Of course, that could just mean they don’t pick up the important aspects of parenting.) She later goes on to argue that studies showing poorer outcomes for children of single-sex parents actually show poorer outcomes for children in worse neighbourhoods (p.304). Harris also notes that studies have not found children of homosexuals to be more likely to be homosexual, though she thinks that may change as more cases mount (p.51).
Much more problematic is this comment: The larger the high school, the greater the choice of social categories. A big city high school is likely, for example, to contain a group of boys who have artistic or theatrical interests and who are not attracted to girls. Groups of this sort are seldom found in small rural high schools, which may be one of the reasons why male homosexuality is much less common in such settings. Having, or not having, a group to identify with could make all the difference to a kid who isn’t sure what sort of person he is (p.277).
There is no source cited for the claim that male homosexuality is much less common in such settings. Which is certainly a pretty silly one: gays fleeing rural upbringings is an archetypal gay experience. They may feel more alienated, but they certainly don’t feel less gay. They may even feel more so, since it is driving their decision to escape. Conversely, it was precisely because I was not theatrical or arty that meant in my large high school (1400 students) I did not hang out with the art-fags. Not feeling myself to be “like them” got in the way of self-understanding. It was precisely because I did not identify very much with any peer group at my surfer high school that I withdrew so much into the home (and books and the company of my parents, particularly Mum).
There is a lot of varying informative and thought-provoking things in The Nurture Assumption, but, like many theorists, Harris is perhaps rather too much in love with her theory.