"The essay on the null hypothesis and Charles Murray"

Arnold Kling:

In my view, once we have accounted for the differences created by the overall cultural environment, genetic inheritance, and gestational variation, there is very little room for specific interventions to make a difference.   In The Nurture Assumption, Judith Rich Harris pointed to evidence that parental behavior makes little difference in children’s outcomes.  If the people who are most heavily involved in raising children make little difference, then what is the likelihood that, say, a particular elementary school teacher or a specific schooling method will make a difference?

Discouraging to say the least, but--with some important exceptions--probably true.