Arnold writes:

My guess is that someone with a high IQ in an adverse cultural setting will not necessarily be healthy and wealthy. Someone with an average IQ in an achievement-oriented cultural setting will tend to achieve a lot.

Both statements are literally true, but we need to be careful. You’d have to be a fool to argue that IQ necessarily leads to health and wealth. But it’s nigh-impossible to find a society where IQ is not one of the best predictors of wealth and health, and implausible to think this relationship is not largely causal. Maybe Cambodia under the Khmer Rouge is a counter-example, though even there, the leaders were a bunch of intellectuals.

Similarly, it’s obvious that – holding IQ constant – people do better in “achievement-oriented” societies. That’s one of the reasons immigration makes the world better off – people move to places where a given level of IQ is more productive. However, this is perfectly compatible with the fact that – holding achievement orientation constant – high-IQ people do better.

Arnold adds:

Cultural influences and emotional health cannot be measured as accurately as IQ. In regressions to explain things like wealth and health, this puts IQ at an advantage and the other factors at a disadvantage. But I do not think that justifies IQ-ism.

Suppose we use religion as a barometer of culture. In the NLSY, I’ve found that there is one religion that – controlling for IQ, education, and more – predicts MUCH higher earnings: Judaism. Thomas Sowell was on to something. In the NLSY, not only do Jews have higher IQs and more years of education, but they earn even more than you would expect given their IQ and education. In a simple linear model, Jews got a $12k bonus. However, the other religions have only a minor effect: Episcopalians only got a $2400 bonus, and every other denomination got less.

My interpretation: Having an achievement-oriented culture can matter a lot. If every group in the world were as focused on achievement as (American?) Jews are, the world would be a lot richer. But at least within the U.S., seemingly diverse religious cultures lead to pretty similar economic outcomes.