Monday, May 22, 2017

Smart's Don't It?

In what the NYT has labelled an "enormous success" a big genome wide association study is reputed to have found a number of gene variants associated with intelligence:

In a significant advance in the study of mental ability, a team of European and American scientists announced on Monday that they had identified 52 genes linked to intelligence in nearly 80,000 people.

These genes do not determine intelligence, however. Their combined influence is minuscule, the researchers said, suggesting that thousands more are likely to be involved and still await discovery. Just as important, intelligence is profoundly shaped by the environment.

Still, the findings could make it possible to begin new experiments into the biological basis of reasoning and problem-solving, experts said. They could even help researchers determine which interventions would be most effective for children struggling to learn.

I'm not too impressed with the story. The second quoted paragraph is misleading - I think it should say that the individual influence of the genes is miniscule (not the combined influence.) I'm also under the impression that the genes are not actually correlated with IQ test results, but with educational attainment, which is taken as a proxy for intelligence.

One of the more interesting bits in the story was this (about height, not intelligence):

But other gene studies have shown that variants in one population can fail to predict what people are like in other populations. Different variants turn out to be important in different groups, and this may well be the case with intelligence.

“If you try to predict height using the genes we’ve identified in Europeans in Africans, you’d predict all Africans are five inches shorter than Europeans, which isn’t true,” Dr. Posthuma said.

It's not obvious to me that much has been learned about the biological roots of differences in intelligence.