In “Why aren’t we smarter already? Evolutionary Limits On Cognition” (ScienceDaily, Dec. 7, 2011), we learn those limits, plus this snippet on European Jews:
Even increasing general intelligence can cause problems. Hills and Hertwig cite a study of Ashkenazi Jews, who have an average IQ much higher than the general European population. This is apparently because of evolutionary selection for intelligence in the last 2,000 years.
Is it? How do we know? Because the authors assume that all intelligence effects are attributed to natural selection. Which ends the discussion.
Amazing amount of Darwin candy in one story.