Via Sully, I find this fascinating article on race and IQ. Read both pages, as the second gets into why environment is important.
I’ve been thinking about this subject for some time. Here are some random thoughts.
No matter how you twist the data, someone with a low IQ doesn’t necessarily have it because of genetics. There are a number of environmental factors that have proven connections to IQ and it seems most of them are negative (and far more prevalent among blacks). Malnutrition, illness, neglect, drugs and poor education can all drive IQ down. These are not factors passed on to children — well, at least not in their genes. The Flynn Effect, the sharp rise in western IQs over the last century, is clearly environmental (and larger than the present black-white IQ gap). Evolution doesn’t work that fast.
Moreover, the drive to reproduce and create a new generation is, in my mind, a far more important characteristic than intelligence. What good is having a high IQ if you can’t pass it on? People complain about the fertility-intelligence anti-correlation. I complain about it all the time when I go to social functions and find I am the only scientist who has spawned. But in a way, this is nature telling us something important — high intelligence (as opposed to slightly above average) isn’t a survival characteristic. If it were, high IQ people would have more kids.
Update: RPL points out, quite correctly, that the opportunity cost of having children is higher for high-IQ people. Agreed. But that opportunity cost is lower than it has ever been. And the reason for not having kids that I hear most often has nothing to do with career, but lifestyle.
It would be interesting to compare the career achievement of high-IQ people with kids to those of high-IQ people without. My personal experience is that my work ethic improved after having a kid. Others’ mileage my vary.
Update: One thing I thought I’d ad: IQ can only get you so far. I work in a high-IQ profession and it’s my experience that smartness helps, but had work and perseverance are the deciding factors. Progress in science, especially, is driven more toil than flashes of inspiration. What was it Edison said about invention?
Always remember, Charles Darwin didn’t have a high IQ. And he glimpsed the inner workings of the world — through years and years of hard work.
Oh, come on, Mike. The dearth of children among high-IQ couples has a lot more to do with the high opportunity costs for successful people to have children in our society. It has little to do with IQ per se, except inasmuch as IQ correlates with success. To use your example, in a modern society Charles Darwin would be as no more likely to have children than a scientist of comparable achievement with a high IQ. Both face large opportunity costs for taking time away from their work.
Moreover, the notion that the most important thing people can leave behind is their genes is naïve. Ideas also count for a lot. If the opportunity cost for a brilliant thinker to have children is that major discoveries get pushed back a generation, then that cost might be too high. This argument is particularly compelling in light of the phenomenon of regression to the mean. The children of people on the tails of distributions tend to be closer to the mean of the distribution, so our hypothetical genius probably won’t have genius children; therefore his children’s labor is an inadequate substitute for his own. Thus, he (and we) would be better off if he wrung every discovery he could out of his own intellect than if he took time off to have children.
-robert.
Good points, both of them. However, tI would quibble that he opportunity cost for having children is lower today than it has ever been. Day care, nannies and so on have shifted much of the actual work elsewhere. I don’t buy this excuse, especially considering that people find the time and money and opportunity cost to acquire expensive furniture and big houses and take foreign trips.
“Moreover, the notion that the most important thing people can leave behind is their genes is naïve. Ideas also count for a lot.”
I agree with this somewhat. But a thousand year from now, only a handful of people from our society will be remembered. A thousand years from now, our descendants might still exist, at least if we don’t elect too many Democrats.
The opportunity cost for having children is higher now than it ever has been precisely because the quality of the opportunities forgone is higher than it ever has been, and the more successful you are, the more valuable are the opportunities you have to give up to have children. You acknowledge some of those costs explicitly in your comment, but you seem to think that because you value them less than you value having a family they don’t count as costs. It ain’t so.
Alternatively, you could view it as an empirical question. When you control for material success, is IQ still significantly correlated with childlessness. I haven’t seen any evidence that it is. In fact, all the evidence seems to be that as a society becomes wealthier, fertility drops across the board, suggesting that wealth, not IQ, is the culprit.
Finally, it’s true that in a thousand years few people will be individually remembered for their accomplishments, but then your descendants a thousand years from now will bear no discernible genetic relation to you either (i.e., a DNA test would show you to be unrelated; that’s recombination for you). However, just as our fertility today gives rise to the generations of tomorrow, our productivity today gives rise to the wealth and prosperity of tomorrow. In both cases the contribution from any individual is tiny, but collectively it makes all the difference. I don’t see that one is obviously more valuable from the other. In the case of a relatively unproductive individual, his genes might be the most valuable thing he can contribute to future generations, but a more productive individual has a progressively higher likelihood of having something more valuable than genes to pass along to the future.
I don’t entirely disagree with you. HL Mencken in “In Defense of Women” made an almost identical argument.