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To illustrate, there is almost no difference between the genetics of humans 20,000 years ago compared to today. Yet there is a vast difference in what people un

by pcrh 5y ago

To illustrate, there is almost no difference between the genetics of humans 20,000 years ago compared to today. Yet there is a vast difference in what people understand and how they interact with the world, i.e. there has been an increase in "intelligence" in the past 20k years without there being any alteration to genetics. It is also shown by the so-called "Flynn effect" [0], which is a substantial rise in measured IQ by over 1 SD in numerous populations during the 20th Century alone. This is comparable to the mean difference in intelligence between individuals, and absolutely cannot be accounted for by changes to genetics. [0] https://en.wikipedia.org/wiki/Flynn_effect https://en.wikipedia.org/wiki/Flynn_effect

xyzzyz 5y ago
> To illustrate, there is almost no difference between the genetics of humans 20,000 years ago compared to today. There is also almost no difference between genetics of humans and chimpanzees. No difference, except in a few areas that happen to matter a lot. As it turns out, 20 000 years is plenty enough for natural selection to make dramatic change in the genetic makeup of the population. For a most obvious example, look at the spread of lactase persistence mutation, which occurred and started spreading less than 20 000 years ago. > It is also shown by the so-called "Flynn effect" [0], which is a substantial rise in measured IQ by over 1 SD in numerous populations during the 20th Century alone. This is comparable to the mean difference in intelligence between individuals, and absolutely cannot be accounted for by changes to genetics. The Flynn gains are hollow, though. They are not on g factor, and it’s the g factor that’s responsible for the predictive validity of IQ. Imagine a society where people use human foot length to measure distances. After a century or two, they observe that everything is getting shorter, a sort of anti-Hubble effect. Nobody noticed, however, that people have become taller on average, and so their feet became longer, so the actual change is only in the used metric, not the latent variable they are trying to measure. Flynn effect is like that.

by pcrh 5y ago

xyzzyz 5y ago

> To illustrate, there is almost no difference between the genetics of humans 20,000 years ago compared to today. There is also almost no difference between genetics of humans and chimpanzees. No difference, except in a few areas that happen to matter a lot. As it turns out, 20 000 years is plenty enough for natural selection to make dramatic change in the genetic makeup of the population. For a most obvious example, look at the spread of lactase persistence mutation, which occurred and started spreading less than 20 000 years ago. > It is also shown by the so-called "Flynn effect" [0], which is a substantial rise in measured IQ by over 1 SD in numerous populations during the 20th Century alone. This is comparable to the mean difference in intelligence between individuals, and absolutely cannot be accounted for by changes to genetics. The Flynn gains are hollow, though. They are not on g factor, and it’s the g factor that’s responsible for the predictive validity of IQ. Imagine a society where people use human foot length to measure distances. After a century or two, they observe that everything is getting shorter, a sort of anti-Hubble effect. Nobody noticed, however, that people have become taller on average, and so their feet became longer, so the actual change is only in the used metric, not the latent variable they are trying to measure. Flynn effect is like that.