Jonah:

So far as the science is concerned, as I noted in the NRODT article you referenced, we should be ready for many more results like this from the genomics people. The results I am reporting on are, in fact, the sound of one shoe dropping. A whole truckload of shoes is waiting to drop.

For example: The Microcephalin genes that Bruce Lahn’s papers are concerned with affect brain development somehow. How? We don’t really know. When the genes misbehave, you get microcephaly — abnormally small brains. So the genes have something to do with brain size. Brain size in humans, however, is severely constrained by the mechanics of human birth — the infant head has to pass through the pelvic opening.

There is not much scope there for genetic variation. (A gene variant that increased brain size 5 percent would not survive long, as the infants carrying it literally could not be born!) Much more likely, these genes control brain organization.

And that raises the question: Do these genes have anything to do with cognitive powers? With the ability to solve complicated problems, plan ahead with foresight, etc. — the kinds of things we measure with IQ and personality tests? We know the variants confer great survival advantages. Well, improved cognition would be a survival advantage, wouldn’t it? So: Are these genes controlling intelligence or personality factors?

It should be easy to find out. Bear in mind that the variants Lahn reports on are present in all populations; it’s only the frequencies of their presence that differ geographically. So take the population of your choice: say, Irish people. Extract a decent-sized sample of Irish people who have the variant form of the gene, and another equal-sized sample of Irish people who don’t. Run the two groups through standard IQ and personality tests, and see how the statistical profiles compare, group A versus group B.

I hear that Lahn himself has actually done some such experiment, and that the results have been written up and are in pre-publication review.

We are therefore not supposed to know what he’s found, but the buzz I’ve heard is that his results are… not p.c.

Note, though, that results like this only become powerfully persuasive when the experiments are repeated by different groups of researchers, and the results keep coming up the same. THAT is when hypothesis turns to fact, and we are not there yet, even if Lahn’s unpublished results are what I hear they are. The mills of science grind slowly, but they grind exceeding small…