December 7th, 2008

breaking bad

Oh Superman

Here's a piece of research which seems as usual to have an obvious flaw.

(Study of war veterans)... those who performed better on intelligence tests tended to have more - and more mobile - sperm.... people with robust genes might be blessed with a biological "fitness factor" making them fit, healthy and smart. Lead researcher Dr Rosalind Arden said: "...our results do support the theoretically important 'fitness factor' idea. We look forward to seeing if the results can be replicated in other data sets, with other measures of intelligence and other measures of physical health that are also strongly related to evolutionary fitness."


But the question about intelligent people isn't why they are so reproductively fit: it's not why there are so many, but why there are so few. Cheetahs are specialised for running, and all cheetahs run very fast. The fast cheetahs have greater 'evolutionary fitness' so there aren't any slow ones any more. That is manifestly not the case with human intelligence. If intelligent men have such a reproductive advantage over unintelligent men - why are they so rare in human populations?

My guess is that sperm quality and brain development are both very dependent on maternal health and childhood nutrition, rather than being joint markers of genetic superfitness. There may also be a link between nutrition and more educated mothers etc. However, there are obvious political and social reasons why people don't want to think about that, and prefer to say there is a class of super-fit spermaniacs.

(To be fair the article quotes a guy at Sheffield university who says "The fact that it's possible to detect a statistical relationship between intelligence and semen quality in adult men probably says more about the co-development of brain and testicles when the man was in his mother's womb" Well, yeah.)
breaking bad

My eccentric theory

I was looking for this other piece of research when I wrote that last post on intelligence but I couldn't find it at the time.

In a study recently published in the Journal of Cognitive Neuroscience, scientists said that normal 9- and 10-year-olds, differing only in socioeconomic status, have detectable differences in the response of their prefrontal cortex, the part of the brain that is critical for problem solving and creativity.


This study will I think be interpreted in three different ways. The right wing response will be that social class reflects innate ability, and that people are poor because their brains don't work properly. The liberal/left response will be that impoverished environments stunt brain development (nutrition, language complexity, mental stimulation).

I've got more sympathy with the second, which is probably right at least in part.

My perspective, which I don't think many people agree with, is that intelligence is a social role, which people adopt or reject according to their social circumstances (leaving aside people with developmental disability). I think we can choose to 'act brainy' - pay sharp attention, be sceptical, dig deep for creative responses. But, in some circumstances this is a very bad idea. It antagonises people. It can alienate people from their social support network. It can complicate tasks that should be simple.

I think people are taught as small children to find a comfortable point in the intelligence spectrum, and apply that much energy as they need to maintain that equilibrium. People in powerless circumstances are taught to protect themselves by being malleable, passive and non-assertive (intellectually). They are taught to have low expectations of themselves.

I think social roleplaying, and the way people find a niche by fitting into the social space available, accounts for a lot of supposed 'variance' in intelligence.