Here's our hypothesis to explain the Hart-Risley findings [on academic success in young children]: The variables they studied--again, the parents' loquaciousness and the children's IQ and school performance--were all effects. The main causal factor was something the researchers apparently didn't think to measure: parental IQ.
Steven Pinker, the Harvard cognitive psychologist, seems to be thinking along similar lines. This morning in response to the Rosenberg post he tweeted: "The Blank Slate lives: Yet another story on parent-child correlations that dares not mention the g-word."
"The g-word" is "genetics," and "the Blank Slate" refers to the view that human beings are essentially fungible--that all differences between individuals and groups, or at least all those that have important social consequences, are the product of nurture rather than nature. It follows from this view that inequalities between individuals or groups can be eliminated by social engineering--by changing the environment in which individuals develop.