[andyjohnson0]

I'm fairly skeptical about IQ, but levels of religious belief may correlate with wider social factors. An interesting source is:

Gregory S. Paul. Cross-National Correlations of Quantifiable Societal Health with Popular Religiosity and Secularism in the Prosperous Democracies: A First Look. Journal of Religion and Society, Vol 7, 2005.

http://moses.creighton.edu/jrs/2005/2005-11.pdf

Quote: "In general, higher rates of belief in and worship of a creator correlate with higher rates of homicide, juvenile and early adult mortality, STD infection rates, teen pregnancy, and abortion … None of the strongly secularised, pro-evolution democracies is experiencing high levels of measurable dysfunction.” Within the US, “the strongly theistic, anti-evolution south and midwest” have “markedly worse homicide, mortality, STD, youth pregnancy, marital and related problems than the north-east where … secularisation, and acceptance of evolution approach European norms".