Archive for the ‘Science’ Category

IQ, Class and Genes

Wednesday, June 1st, 2005

After reading the NYTimes series on class, and my post about it, a reader emailed me to suggest that the discussion of inherited position within a "meritocracy" was ducking the question of genes and IQ.  For example, one of the strongest predictors of how well kids do in school is their mother’s level of education.  Is this because well-educated mothers read to their kids a lot and use more extensive vocabularies, or because they continued in school because they were good at it, and they passed those genes onto their kids?

It’s a fair question, and the truth is almost certainly a bit of both.  A paper by Erik Turkheimer et al. a few years ago found that among very poor families, the environmental conditions were more important than genes in predicting IQ, while among middle- and upper-income families, genetic factors were dominant.   The published article is pretty technical, but there’s a nice layperson’s discussion of it and interview with Turkheimer available from Connect for Kids.

This research suggests that there’s a threshold level below which children aren’t able to develop to their full genetic potential.  But above that level, what parents do isn’t as critical (at least with regard to IQ) as we often think.  As Turkheimer says in the interview:

“In the range where a lot of people spend their time…you know, ‘Should I hang the black and white mobile over my kids’ crib?’ kind of thing, it probably does not matter.”

Human Equality is a Contingent Fact of History

Thursday, October 28th, 2004

Human Equality is a Contingent Fact of History” is the title of an essay by Stephen Jay Gould, originally published in Natural History magazine, and later included in his essay collection, The Flamingo’s Smile. Gould was an elegant writer, and the essay is worth reading in its entirety. (To read beyond the page in the link, increment the page number in the URL by one.)
Gould’s argument is, first, in support of human equality as not just a moral principle but a scientific fact — at least with respect to racial differences. He writes:
“Human races are not separate species (the first argument) or ancient divisions within an evolving plexus (the second argument). They are recent, poorly differentiated subpopulations of our modern species, Homo sapiens, products at most of tens or hundreds of thousands of years, and marked by remarkably small genetic separations.”
But then he goes on to point out that there’s no biological reason why this had to be the case. There could conceivably have been more than one human species, both intelligent, but with meaningful biological differences. How we would have treated each other in that case — what rights and obligations we would have — is a fascinating topic for thought.
I was reminded of this essay upon reading in paper today that researchers have found remains on Flores island of a new human species that they think lived about 10,000 years after the Neanderthals had become extinct. And it ties in with my thoughts yesterday about whether it’s a good idea to base our moral arguments on factual premises.
A small request:
Some of you may have heard about the controversy that erupted earlier this year when someone discovered that when you entered the word “Jew” into Google, the top link was to an anti-semetic site. The response, after a flurry of initial accusations, was a campaign to get people to link the word “Jew” to its entry on Wikipedia, as I just did. This is now the top result of a google search.
Well, in searching for this essay on line, I discovered that the top hit on “human equality contingent fact history” is for David Duke’s official website. Ugh. If you find this as horrifying as I do, please consider providing a countervailing link to the actual essay, like this:
Human Equality is a Contingent Fact of History
or to Gould’s page on WikiQuote, like this:
Human Equality is a Contingent Fact of History
November 4 update:
The David Duke site is no longer the first result on Google — now this site is. Not quite what I had in mind, but at least anyone coming here will be pointed to the full article.

The role of research

Wednesday, October 27th, 2004

In this week’s New York Times Magazine, there’s a nice article about the 22-year-old daughter of a lesbian couple. They suggest that she’s one of the oldest children deliberately conceived and raised by a homosexual couple (as opposed to having been born before one of their parents came out). This seems plausible to me — I grew up in Greenwich Village, and attended what is probably the only public elementary school in the US that is next door to a gay bookstore, but to the best of my knowledge, none of my classmates had gay or lesbian parents.

However, the part of the article that caught my attention the most was this comment by Judith Stacy, a sociologist who rejects the conventional wisdom that the children of gay and lesbian parents are no more likely to be homosexual than the children of heterosexual parents.

”My position is that you can’t base an argument for justice on information that’s empirically falsifiable in the long run,” she said. ”If your right to custody is based on saying there are no differences, then research comes along and says you’re wrong, then where are you?”

This point has wide applicability beyond the specific question raised in the article. One example that comes to mind is child care. The research at this point is pretty darn inconclusive. There’s some evidence that kids in child care have better cognitive skills, some evidence that they are more aggressive (although within the range of normal kid behavior), some evidence that very long hours of child care in the early months may have negative effects, especially for shy kids. It’s all based on observations, rather than on rigorous evaluations, so anyone who says that they have proof of causation is lying. (For a solid review of the data, my favorite recommendation is Working Families and Growing Kids, by the National Academy Press.)

But let’s say a report came out next week that had solid clear findings suggesting that children who spend their first two years in child care have worse outcomes than children who spend them in primarily parental care. What would we do? Would we ignore the findings, saying that they’re just another way to beat up on working mothers? Would we demand higher quality child care? Would we demand that the government provide childrens’ allowance to enable low- and moderate-income parents to cut back on work? If no possible research findings would change the policies and practices that we support, we should acknowledge that they are based on our normative values rather than on facts.

A recent study found…

Friday, September 17th, 2004

Articles about two studies on the causes of childhood leukemia crossed my desk this week. The first reported on a study published in Cancer Causes and Control which links it to what mothers ate in the year before they became pregnant — the more protein, vegetables and fruit the mothers ate, the lower the risk of cancer. The other reports on a paper presented at a British conference suggesting that night-time exposure to light could be a cause of leukemia.

I have very mixed feelings about studies like these. Leukemia is a horrible disease, and of course we’d want to do what we could to reduce the incidence of it. But it’s bad enough having a child with a life-threatening disease without having to worry that you might have caused it. Parenting these days seems to be an endless litany of things that you shouldn’t do.

I confess — my 3 1/2 year old likes the light on at night, and since he and his brother share a room, that means the baby is being exposed to it too. Not only do I feed them YoBaby yogurt (which the puritans on my moms email list disapprove of because it has sugar added), I let them have cake and cookies too. My older son only eats vegetables when I hide them in muffins. He only brushes his teeth once a day, and we haven’t started brushing the baby’s teeth yet. Shoot me now.