More on The Nurture Assumption

So, I've been looking at a bit more on The Nurture Assumption - I found a review by Steve Sailer:

In contrast, her third assertion -- parents don't matter -- is plausible only within her narrow, arbitrary boundaries. To fully explain human behavior, everything matters. Anything conceivable (whether genes, peers, parents, cousins, teachers, TV, incest abuse, martial arts, breastfeeding, prenatal environment, etc.) influences something (whether personality, IQ, sexual orientation, culture, morals, job skills, etc.) in somebody. 

More interestingly, a review by a psychologist:

Ms. Harris notes that her largest problem with her book since its publication is that of people quoting her ideas and statements out of context, and making judgments of the book without having read it.

*Cough*, who, me?

He also has a more detailed criticism of the book, arguing that she overstates her case.

Let's be more specific. Ms. Harris says that smart parents read to their children, and their children grow up smart. Thus, some conclude, reading to your children makes them smart. She offers instead that smart people have smart genes which they pass to their children, and that's what makes them smart; the reading is irrelevant. But take this further. Parents who are great swimmers may pass on genes for great swimming to their children. But, if they never take their child to a pool, lake, or ocean, the child is unlikely to learn to swim and will never be a great swimmer regardless of her genes.

I think Ms. Harris is correct in pointing out that even with great genes, your daughter may learn to swim, but may never be a great swimmer unless her friends value swimming or at least don't devalue her for her swimming. Likewise, if you want her to swim, sending your daughter to a school with a swim team, and making sure she has the opportunity to associate with other children who value perseverance, athletics, internal motivation, and swimming are more likely to be effective than pressuring and ordering her to swim.

(emphasis mine)

The main thing to take away from the book would probably be that peers matter more than parents would expect. And, maybe we shouldn't fret too much about how the way we raise our kids.

Anyway - that PsychPage website looks like it has quite a few interesting posts - I'll look at the rest later.

Nature and Nurture

So, there seems to be quite a lot of disagreement on how to raise children. But what if it hardly makes a difference?

Identical twins, whether raised together or apart, turn out to be very similar, but one still finds differences in IQ and personality. The cause of those differences must be the different environments experienced by the twins, but can't be characterized by simple variables of the sort listed above: it is not the case that the twin raised by the higher SES family has, on average, the higher IQ! In fact, twins raised in the same family are about as similar as those raised apart, so family shared environment does not produce a measurable influence. See below for a plausible model that accounts for such outcomes.

By now these results are well understood and accepted by experts, but not by the general population or even policy makers. (See the work of Judith Rich Harris for popular exposition). The naive and still widely held expectation is that, e.g., high SES causes a good learning environment, leading to positive outcomes for children raised in such environments. However, the data suggests that what is really being passed on to the children is the genes of the parent, which are mainly responsible for, e.g., above average IQ outcomes in high SES homes (surprise! high SES parents actually have better genes, on average). Little or no positive effect can be traced to the SES variable for adopted children.

The implications are quite shocking, especially for two groups: high investment parents (because the ability of parents to influence their child's development appears limited) and egalitarians (because the importance of genes and the difficulty in controlling environmental effects seems to support the Social Darwinist position widely held in the previous century).

Steve Hsu's explanation involves learning styles, despite the fact that those don't seem highly regarded in the psychology community. One more contradiction, I guess.

See here for a bit more on nature, nurture and randomness - calling it "randomness" makes more sense to me then "non-shared environment".

So, does that mean that whatever the parenting style, the effect is negligible? On intelligence and personality at least, maybe parents can have very little influence on the nurture bit. That is surprising.