Monday, October 21, 2013

Nature vs. Nurture: Does Parenting and Enrichment Matter to Outcomes

As parents, Andrea and I are have read numerous books, articles, and studies on child rearing. We have read about how an enriched home environment generally leads to readiness and success in school. As an example, this New York Times article discussed the differences between homes in different economic classes:

They found, first, that vocabulary growth differed sharply by class and that the gap between the classes opened early. By age 3, children whose parents were professionals had vocabularies of about 1,100 words, and children whose parents were on welfare had vocabularies of about 525 words. The children’s I.Q.’s correlated closely to their vocabularies. The average I.Q. among the professional children was 117, and the welfare children had an average I.Q. of 79.

When Hart and Risley then addressed the question of just what caused those variations, the answer they arrived at was startling. By comparing the vocabulary scores with their observations of each child’s home life, they were able to conclude that the size of each child’s vocabulary correlated most closely to one simple factor: the number of words the parents spoke to the child. That varied greatly across the homes they visited, and again, it varied by class. In the professional homes, parents directed an average of 487 “utterances” — anything from a one-word command to a full soliloquy — to their children each hour. In welfare homes, the children heard 178 utterances per hour.
I've also read books like NurtureShock that make a strong case that in child rearing, providing enrichment opportunities leads to long term economic success and hence more opportunities in life.
Annette Lareau, in a landmark study titled Invisible Inequality: Social Class and Childrearing in Black Families and White Families claims that "middle-class parents engage in concerted cultivation by attempting to foster children's talents through organized leisure activities and extensive reasoning," and concludes that "middle-class children gained individually insignificant but cumulatively important advantages. Working-class and poor children did not display the same sense of entitlement or advantages."

Our three children participate in organized sports, competitive chess, music lessons, language lessons, and many other organized activities. In fact each child has between 6 and 10 organized activities each week. Sometimes this is logistically difficult (like on Wednesdays, when my middle son goes from school to assisting me coach elementary school chess, to Hebrew School and finally to soccer practice, eating dinner and changing in the car along the way). So, when my wife recently heard a Freakonomics podcast arguing that enrichment makes little difference, it gave her pause. Dubner and Levitt essentially argued that success depends on IQ, which is highly heritable and so it makes little difference if you provide your kids with piano lessons and immersion language experience or use the television as an electronic babysitter; the kids will turn out how they will turn out. In fact, during the show one interviewed economist/parent said that there was "great culture" on TV and that he'd be very upset if his kids did not enjoy The Simpsons.

The economists on the podcast made a strong case, and made me aware of a whole other body of literature like Bryan Caplan's book Selfish Reasons to Have More Kids. Further research turned up gems like Judith Rich Harris's The Nurture Assumption, that hold that genetics accounts for almost all of the difference in outcomes between children.

If how we raise our kids has no real effect on their income as posited in this excerpt, then why bother with the enrichment:
"The Korean War orphans were adopted in the ‘50s and ‘60s at a time when it was much easier for low-income families to adopt. So, families were eligible as long as they were twenty-five percent above the poverty line, which would be quite unusual today. So, these kids were raised by a much broader range of the socio-economic spectrum than would happen to adoptees today. And yet, the finding of the study by Bruce Sacerdote was that the kids raised by the very poorest families grew up to have the same income as the kids raised by the very richest families. It’s striking that it’s the kind of thing that you would think of as being more about upbringing broadly defined than a lot of other traits. So it could be that it’s actual upbringing where your parents instill the value of a dollar and hard work in you. Or it could be something more like nepotism where because you get raised by the right kind of parents you get good connections, they actually make a phone call for you. And yet, actually the very best studies of the nature and nurture of income find that parents do have a moderate effect on your early income when you’re in your twenties, but basically zero for the rest of your life."
So, that leaves me with a mountain of evidence that claims that parenting style makes a huge difference in outcomes and that other parents are investing ever more heavily in providing an enriching environment to secure spots for their children in ever more selective colleges, and another mountain of evidence that says I'm driving myself crazy acting as a taxi to get my children to an immersion Chinese School, Tae Kwon Do, music lessons, etc. and that all that work will in the end make little difference in outcome except to make my children, my wife, and me more stressed.

I cannot reconcile these two views of how to parent, but in discussions with my wife I've had several thoughts on the matter. Let's start with this: If the Freakonomics view of the world is right - that you will grow up to be as successful as your genes for intelligence allow and that environment makes little difference in that outcome-  it leads to some very strange questions and conclusions.

There has been a marked decrease in social mobility in the United States over the last thirty years. If genes determine income and environment has only a small effect on outcomes, how did the genes for IQ become suddenly so much more segregated along class lines in under a generation? What about social mobility in other countries? If genes determine outcomes why should that be more truly the case in the United States than in other Western countries? If parenting makes so little difference, if it is all nature and not nurture, does that lead to a world where the poor are inferior and reducing social stratification is impossible? Isn't this the same "the poor are poor because they are genetically inferior" eugenics reasoning that was used to stigmatize and sterilize the poor in decades past?

Andrea argues that it is possible that a certain amount of environmental support and "enrichment" provide linear gains in ultimate adult achievement, but that beyond a certain point, additional enrichment makes little difference. So is it possible that all the studies showing a large benefit of enrichment were done in environments with little base intellectual stimulation, while the studies showing little difference in outcomes as a result of environmental enrichment were done in environments that were already near the asymptote?

Could the study of adopted Koreans that showed no significant benefit to being raised by affluent families be confounded by a society that in the 50s and 60s discriminated against Asians, which limited their upward mobility?

I think that the idea that environment makes no difference flies in the face of the evidence I see every day. I have two children in an award-winning school district whose peers are solidly upper middle class, and one child who is in an impoverished district that has fired all of its elementary school art, physical education, and music teachers and greatly reduced its gifted and talented program. I have been volunteering in both school systems for 15 years, several hours a week, almost all of it spent with K-4 children. I can tell you that the children in the impoverished school system did not appear to be significantly less smart than their counterparts in the affluent district, but have fallen behind for a variety of reasons that have to do with environment (to the point where I am seriously considering giving up an immersion Mandarin program that I value highly to move my son to the more affluent district, but that is a whole different post).

I'd appreciate feedback on this post but may have to find a more trafficked place to put my questions.