Review by Neil Salkind

Before we start, let's get one thing straight. In her provocative and beautifully written book The Nurture Assumption, Judith Rich Harris does not state that parents have no effect at all on their children's development. That's what the popular press (backed up by hype from her publisher) wants you to believe. Rather, Harris argues that the importance of the parents' role has been overestimated. Parents do matter, but not as much as we psychologists and parents have been led to believe, both by the data and by the history and literature we inherited. Instead, it is the peer group that is of paramount importance in the formation of personality and the transmission of culture.

Harris takes almost 500 pages (including 717 endnotes and a reference list of 671 items) to argue her case convincingly. She begins with findings from studies of behavioral genetics. These studies have shown that children from the same family are often very different in personality, despite the fact that they share both genes and a home environment. Though their shared genes make biological siblings more alike, the shared environment of the home seems, if anything, to make them more different. The source of these differences -- which are found in twins, ordinary siblings, and adoptive siblings alike -- is the mystery that Harris sets out to solve. She gathers together much other evidence to support her case that the solution to the mystery will not be found in the family home. Accordingly, she turns her attention to the child's life outside the home.

The conclusions she reaches as a result of her analysis of the evidence (which has been criticized by some as being biased and limited in scope) are that "children identify with a group consisting of their peers, that they tailor their behavior to the norms of their group, and that groups contrast themselves with other groups and adopt different norms." Harris calls this approach "group socialization theory." Those who are familiar with the historical arguments about the role of parents may remember Sandra Scarr's statements about the way children create their own environments.

The most compelling argument against Harris's thesis is that there are other non-shared sources of variance in personality, aside from experiences in the peer group. For example, a mother might give one child more attention or affection than another. But if that were the case, Harris argues, we would expect to see sizable differences in personality as a function of birth order; moreover, only children should be noticeably different from children with siblings. Neither turns out to be the case. However, it is still possible that other environmental differences -- either within or outside of the family - can exert important influences on personality development.

Whether or not you agree with her thesis, there's more to like in Harris's book than the intellectual stimulation and controversy it excites. The attraction for me is in the impact that a new and fresh perspective can have on what and how we teach. Advanced undergraduate and graduate students in our various fields should read and discuss this book as a central theme in any course dealing with children's social development. And the work itself is a testament to how someone outside of the establishment (Harris does not have a Ph.D. and has never taught at a university) can make a significant contribution -- perhaps a lesson that we should be listening more and talking less.

A wealth of commentary on Harris's book -- pro and con -- is available on The Nurture Assumption website (tna/index.htm). The amount of interest in this book is testimony, not just to its theoretical importance and implications for raising children, but to the role that new ideas can play in stimulating thinking and research in the field of child development.