We have discussed here before how IQ (which Steve Hsu wisely calls a colloquial term) is a good group tendency measure, but no better than a moderate predictor of individual success. If you compare a hundred people with IQ 100 and a hundred people with IQ 110, the latter group will have less crime, more years of education, higher incomes, more stable relationships and better overall health. But in both groups of 100 there will be a lot of variation. The book for this is Hive Mind: How Your Nation's IQ Matters So Much More Than Your Own, by Garett Jones. He embraces the seeming contradiction rather than avoiding it. He stresses the greater patience and cooperativeness of those with higher IQ, even though those are more modest, have a greater cultural impact than the usual cognitive measures we associated with g-factor intelligence. Even though his ideas for raising national IQ do not look that promising to me, I'm likingthe book for other reasons.
Into this mix comes some interesting support. Over the last few decades we have revamped our thinking about Neanderthals, that they were more intelligent than we had credited, created art and used tools more variously, and contributed some to our ancestry. I said here last year that perhaps we supplanted them because we were just meaner.
Neanderthals had larger brains, so were unlikely to be less intelligent. Their tool-making is more individualistic, suggesting that each tool-maker was more creative. What would cause that? Necessity. If you lived in larger groups, which in turns had contact with other larger groups, sharing genetic material (usually by exchanging daughters), then everyone didn't have to reinvent the wheel* themselves. The group knowledge is a repository of memory. Neanderthals were more likely to have autism-associated genes than our African ancestors. They lived in smaller, more densely related bands.
(Diagram from Razib Khan's substack)
In fact, Neanderthals are often not much related to other bands a hundred miles away, even over centuries.
So they may have each been smarter, more creative, but were less social, and less likely to have lots of shared memory, shared culture. Homo sapiens were smarter as a whole, and thus exploited environments more fully.
And if it came to a fight, one side had a lot more people than the other.
I have been a loud voice favoring the view that genetic changes have created the cultural ones. I am apparently wrong about that. David Reich's group has shown that genetic changes seem to lag behind the cultural ones. Not so very long, but noticeably. Once a practice has begun, such as relying more on milk products, genes for lactase persistence begin to be selected for. When you think of the math alone, this makes sense, and we will use lactose as our example. Waiting around for a single chance mutation, and then hoping that this one individual with that advantage reproduces is a bit chancy. But if the cultural habit of using milk products for food, even if poorly digested and causing intestinal problems, becomes widespread in an area, then any number of small advantages will be called out. A mutation has a better chance. I had never thought of it that way. The genes for lactase persistence actually show up a few thousand years later than the dairy use. But once they existed, they rapidly made their holders healthier and longer-lived.
*Almost literally
1 comment:
Almost literally, but not quite. The wheel dates back only to about 3,500 B.C. Spears and flint-axes, certainly.
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