Social Econ Blog

Judy Harris makes interesting arguments about parenting. A summary of her latest work can be found in this NYTimes Book Review.

Harris' first book "The Nurture Assumption" attacked the notion that parenting styles shape children. Her new book, "No Two Alike," seeks to explain "why people -- even identical twins who grow up in the same home with the same genes -- end up with different personalities." Her answer:

From this evolutionary logic, Harris builds a theory of personality based on three systems in our brains. The socialization system absorbs language, customs and skills, making us more alike. Mommy and Grandma wear dresses; you're a girl, so you want a dress too. The relationship system distinguishes people so we can deal with each one appropriately. Crying gets milk from Mommy but not Grandma; Billy is gentle, but Bobby hits people. Even random differences are important: Anne helped you with your homework, but her twin sister owes you a dollar. You find ways to tell people apart because you have to.

...

[Third] ..Thehe status system. Your socialization system figures out how to conform to your group. Your relationship system figures out how to get along with each person. Your status system figures out how to compete. It monitors people's reactions, gathering information about how smart, pretty, weak or talented they think you are. It looks for virtues, activities and occupations at which you're most likely to best your peers. It notices tiny differences between the way people regard you and the way they regard others in your peer group, or even your twin. By choosing pursuits based on these differences, it magnifies them. It drives you to be different.

Further:

The reason parental influence doesn't control children's behavior outside the home is that they adjust to context. "Children are capable of generalizing — of learning something in one context and applying it in another — but they do not do it blindly," Harris observes. At home, where you're the younger sibling, you yield. At school, where you're one of the bigger kids, you don't. And unlike other animals, you can shuffle your self-classifications. In seconds, you can go from acting like a girl to acting like a child to acting like a New Yorker.

In short, the evolutionary logic that makes us different from one another will gradually make us different from ourselves, context by context. Personality -- behavior that is "consistent across time and place," as one textbook puts it -- will fade.

Harris' essentially argues that situations matter. People respond to the specific incentives in their specific situations. Thus, we shouldn't expect to observe much in term of consistent behavior across time and place (or personality). If you are really interested in this topic, I highly recommend Nisbett and Ross' "The Person or the Situation." One of the most interesting books I've read in the past several years.

While I agree that personality is something of a myth, I disagree with her view that parenting can't control a child's behavior outside the home. First, as we discussed in class last time, parents play a vital role in selecting the situations the child is likely to be in. Further, parents can and do shape the relative payoffs to decisions made outside the home. First, parents educate their children about the expected long term effects of different choices. Second, to the exent parents are aware of choices made elsewhere, they can (and do) punish and reward children for choices made outside the home. Thus, the probability that parents will find out about their choices and the expected rewards and punishments are part of the relevant context that shapes children's decisions outside the home. Thus it is hard for me to agree that parenting doesn't matter. Maybe popular parenting methods aren't very effective, but that doesn't mean, in principle, parent's have little effect.