Such a good book that it will necessitate multiple blogposts. Robust and true when it was published in 1998. Still robust and true today. Excerpts from the first 50 pages:
"Let me take this opportunity to clear up some misunderstandings about the role of peers in “how we turn out.” I’m talking about something that begins as soon as children go out of the house and find themselves in a place where there are other children. It can begin as early as age two and certainly, for most children, by age three. Group socialization theory has to do with the way a child’s mind works. Children’s minds work no differently today than they did in earlier times.
The fact that only children don’t differ in any important way from children with siblings, for example. Or that young children who go to day-care centers don’t differ in any important way from those cared for at home by their parents. Or that those who have two parents of the same sex don’t differ in any important way from those who have one of each sex. And so on. You’ll find lots of other observations in this book that don’t fit into the standard view of child development.
Over time, the early, angry response to The Nurture Assumption has softened noticeably, both within and outside of academia. Today, the book is widely cited in textbooks and journal articles.9 It’s assigned and discussed in courses in many colleges and universities; it shows up on exams.
My primary interest is environment, not genes. But we cannot tell what the environment does to a child unless we know what the child brings to that environment.
One of my hopes was that I could make child-rearing a little easier, a little less stressful for parents. Alas, it has not happened, as far as I can tell. Parents are still using the anxiety-ridden, labor-intensive style of parenting prescribed by their culture; they’ve paid no attention to my well-meaning advice to lighten up. Even my own daughters are rearing their children that way. But why should I expect to have an influence on my own daughters?
A strange factoid in our True-But-Inconvenient file is that children always end up with the language and accent of their peers, not of their parents. Children of immigrants pick up language from the playground so well that they are soon ridiculing their parents’ grammatical errors. Acquiring the particulars of a native language is an example of cultural learning. Children in Japan speak Japanese, children in Italy speak Italian, and these differences have nothing to do with their genes.
The thesis of The Nurture Assumption—that in the formation of an adult, genes matter and peers matter, but parents don’t matter—raises issues about children and parents that could not be more profound. It calls into question the standard social science model of the child as a bundle of reflexes and a blank cortex waiting to be programmed by benevolent parents.
Today, children win or lose by their ability to prosper in this milieu; in the past they lived or died by it. It makes sense that they should take their calories and protection from their parents, because their parents are the only ones willing to provide them, but that they should get their information from the best sources they can find, which might not be their parents. The child will have to compete for mates, and before that for the status necessary to find and keep them, in groups other than the family—groups that play by different rules. Nature surely did not design children to be putty in their parents’ hands.
The data showed that growing up in the same home, being reared by the same parents, had little or no effect on the adult personalities of siblings. Reared-together siblings are alike in personality only to the degree that they are alike genetically. The genes they share can entirely account for any resemblances between them; there are no leftover similarities for the shared environment to explain.8 For some psychological characteristics, notably intelligence, there is evidence of a transient effect of the home environment during childhood—the IQ scores of preadolescent adoptive siblings show a modest correlation. But by late adolescence all nongenetic resemblances have faded away. For IQ as for personality, the correlation between adult adoptees reared in the same home hovers around zero.
Results in behavioral genetics are what statisticians call “robust.” Study after study shows the same thing: almost all the similarities between adult siblings can be attributed to their shared genes. There are very few similarities that can be attributed to the environment they shared in childhood."