So says a soon to be published study.
Evolutionary psychologist Satoshi Kanazawa at the the London School of Economics and Political Science correlated data on these behaviors with IQ from a large national U.S. sample and found that, on average, people who identified as liberal and atheist had higher IQs. This applied also to sexual exclusivity in men, but not in women. The findings will be published in the March 2010 issue of Social Psychology Quarterly.
The IQ differences, while statistically significant, are not stunning — on the order of 6 to 11 points — and the data should not be used to stereotype or make assumptions about people, experts say. But they show how certain patterns of identifying with particular ideologies develop, and how some people’s behaviors come to be.
The reasoning is that sexual exclusivity in men, liberalism and atheism all go against what would be expected given humans’ evolutionary past. In other words, none of these traits would have benefited our early human ancestors, but higher intelligence may be associated with them.