the upper-middle-class kid grows up in an environment that constantly pushes him to develop the cognitive and motivational skills needed to be a good student; the low-income kid's environment, on the other hand, pushes in the opposite direction.
Child psychologists Betty Hart and Todd Risley have tested the effect of class on the differences in how parents interact with their young children. After observing several dozen families with toddlers over the course of a couple of years, they were able to document dramatic differences in the intensity and nature of the verbal stimulation the kids were getting: Professional parents directed an average of 487 "utterances" per hour toward their children, as compared to 301 for working-class parents and only 176 for welfare parents. The quality of those utterances was also very different: Among professional parents, the ratio of encouraging to discouraging utterances was six to one; for working-class parents, the ratio slipped to two to one; and welfare parents made two discouraging utterances for every encouraging one. The consequences were predictable: By the time the children in the study were around three years old, the ones from professional families had average vocabularies of 1,116 words; the working-class ones averaged 749; the welfare kids, 525.
I think that my co-blogger would go ballistic over this "nurture assumption" methodology. In fact, in about an hour I am going to be talking to my AP statistics class about the difference between an observational study and an experiment, and this will be a good illustration of what is problematic with the former.
Instead, suppose that a sample of welfare kids were adopted by professional parents, and vice-versa. Anyone care to bet that at age three the ratio of the vocabulary of the welfare kids adopted by professionals to that of the professional kids adopted by welfare families would be 2 to 1? I bet it would be 1 to 1 or less.
In an email, Brink says that he finds genetic fatalism "completely unpersuasive." I view genetic fatalism as a null hypothesis that is very difficult to reject. That is, it is extremely rare to find interventions with reliable long-term effects on cognitive ability.
I believe that culture matters. However, I also believe that culture evolves slowly, and it's not something that responds in predictable ways to the policy dials being twisted by legislators and bureaucrats.
Still, I can't disagree with Brink when he says,
libertarians have their own good ideas for boosting human capital and fostering assimilation. Among them are: greater competition in the school system, cessation of the drug war that so needlessly fosters criminality, and elimination of occupational licensing restrictions that block opportunities for entrepreneurship among the less credentialed.
I am somewhat pessimistic on competition in the school system as a panacea. I favor it, of course, but I suspect that the benefits would show up more in lower costs than in better outcomes.