Satoshi Kanazawa is an evolutionary psychologist at the London School of Economics. In a study published in Social Psychology Quarterly, Kanazawa argues that more intelligent people are statistically more likely to hold liberal/atheist views that are "novel" to the human species in evolutionary history.

Much as I would like to go along with data that suggests that people with a liberal outlook are more intelligent, I have a few reservations about Kanazawa's approach. For starters IQ per se isn't a reliable indicator of intelligence. Moreover the differences in the IQ levels he cites in the study are so small, it could be a mistake to use the data in support of sweeping theoretical conclusions, particularly with respect to evolutionary considerations.

But yes, data does indeed exist that seems to suggest liberals are somewhat smarter - at least where IQ is concerned. For what it's worth some of the stats come from two U.S. surveys - The National Longtitudinal Study of Adolescent Health aka Add Health and the General Social Survey (GSS).

The Add Health study shows that the mean IQ of adolescents who identify as "very liberal" is 106, compared with a mean IQ of 95 for those who identify as "very conservative". The number of participants in the Add Health study was around 20,000.

Other studies conducted elsewhere have come up with similar findings. A study in the UK conducted by the University of Edinburgh and the UK Medical Research Council that ran over 24 years surveyed 6,000 children. It found that those with higher IQs were more likely to vote Green or Liberal Democrat in later life, and moreover were more likely to vote in general and get involved in the political process.

The study broke down this way... those who in later life voted Liberal Democrat or Green, had childhood IQ's that averaged 108. Those who voted conservative in later life had an average childhood IQ of 103.7. Those who voted for the British National Party (BNP) had the lowest childhood IQ average of 98.4.

Okay but... when Kanazawa makes similar data evolutionarily significant, he loses me. It would seem he also loses Prof PZ Meyers over at Pharyngula who describes Satoshi K as "the Fenimore Cooper of Sociobiology, the professional fantasist of Psychology Today".

An in-depth look at Kanazawa's study - here.

Toronto Star article on the study - here.