Nature, Nurture, Etc.

NATURE, NURTURE, ETC….It’s been a while since we had a rollicking nature vs. nurture discussion here, so here’s some new fuel for the fire from Alex Tabarrok, taken from a recent paper by Bruce Sacerdote.

Sacerdote examined various outcomes of Korean children who had been randomly assigned to adoptive families in the U.S. during the 70s, and as the chart on the right shows, he concluded that family income had no effect at all on the eventual earning power of adoptees. Conversely, it had a big effect on biological children. In other words, being raised in a high-earning family doesn’t seem to have much effect, while being born to to a high-earning family does.

Sacerdote also looks at some other variables and concludes that income, college graduation rates, height, and obesity are correlated significantly more highly for biological children than for adoptees. Conversely, smoking and drinking behavior is about the same, indicating that these traits are strongly affected by family environment.

It’s ironic that research like this is so often embraced by conservatives as evidence that government programs ought to be abolished ? looky here, biology is destiny and there’s not much to be done about it. Although studies like this do indicate a strong biological basis for a variety of behavioral traits, they’re also part of a growing body of research indicating that most families ? at least, those outside the extremely dysfunctional low end ? have very little impact on their childrens’ outcomes. Environment does play a powerful role in nearly every element of behavior, but it’s mostly environment outside the family. Not exactly what the family values conservatives want to hear.