Jews, Jesuits, Geniuses: The Religion-IQ Link Is JUST a Correlation!

Does religiosity cause stupidity?

Posted Apr 29, 2010

My son Dave (who also has a Psych Today blog on evolution and cinema) had his IQ measured in grammar school, and it came in at 147. A decade later, he scored nearly perfectly on the GREs. Yet he goes to church on Sunday. I don’t know my colleague Adam Cohen’s IQ, but he has a Ph.D. from the University of Pennsylvania and has published numerous articles in prestigious psychology journals, so I’m guessing he’s not mentally retarded in any serious way. Yet he avoids eating leavened foods during Passover, and goes to synagogue on Saturday.*

I am bringing these fellows up neither to intentionally embarrass them nor to advertise that I have intelligent church-going relatives and friends. Instead, it is to make two points about an earlier posting of mine, titled: Atheistic liberals are more intelligent, but for a funny reason

These are two points that every psychology professor makes in every introductory psychology class every semester: First, correlation does not establish causation. Second, any behavioral outcome is determined by a complex interplay of multiple variables, not by a single variable. 

I actually turn off comments on this blog, not because I don’t care about other people’s opinions, but because I care too much. I have a day job as a university professor, and it would be too tempting to spend hours reading people’s reactions to my ruminations, then get all emotionally worked up about the most fanatic and loony of those reactions (take a look at the comments posted after almost any article posted online with political or religious connections, and you will see some serious invective being spewed).

But the earlier post on atheistic liberals was read by over 165,000 people, and several folks sent me links to other websites where it was generating a lot of discussion. I was of course unable to resist a peek at those websites, and although I read only a small sampling, I was pleasantly surprised to see little invective, and several very thoughtful comments in the sample I read. Several of those comments involved alternative explanations of the possible link between religion and IQ, several others pointed to exceptions to any such relationship (very religious people who were quite intelligent, for example), and a few complained that I seemed to be offering an overly simplistic explanation of what is likely a complex phenomenon. Given my day job as a professor, I was inspired to respond with a few points we often tell students to keep in mind when they hear about psychological research with which they are inclined (often justifiably) to disagree: 

Correlation Does Not Establish Correlation: Religion does not make people stupid

In my earlier posting, I briefly mentioned data that Satoshi Kanazawa had posted. Those data indicated: a) a 6 point average IQ advantage for the extremely non-religious over the extremely religious, b) a 12 point average IQ benefit for the extremely liberal over the extremely conservative.  I suggested one possible explanation for these relationships: Members of conservative religious groups are, on average, playing a different mating strategy—one characterized by earlier reproduction and more children, and one supported by religious prohibitions against promiscuity and nonmarital sex. People who go to graduate school, medical school, and law school tend to delay starting their families, and consequently are, on average, less attracted to strictures that will keep them celibate until they are a decade past sexual maturity. I cited some data generated by my colleague Jason Weeden that lends support to a central role for sexually conservative attitudes in church involvement. 

Here are some things I was NOT saying: Religious conservatism is caused by stupidity. Stupidity causes religious conservatism. Intelligence directly causes atheistic liberalism. Although there are logical arguments one could make against many religious beliefs (see Dawkins God Delusion for a few such arguments), I was explicitly suggesting an alternative: that one could explain the link between religious conservatism and IQ as a very indirect byproduct: Intelligent people are attracted to higher education, this lessens the attractiveness of belonging to groups that prohibit nonmarital sexuality, nothing logical required, in fact, the relationship is indirect. 

Reality is Complex: There is likely more than one pathway to piety (or impiety)

Another thing I was not saying was this: religious beliefs can be fully explained as mating strategies. Any given correlation also allows for multiple causal relationships between any given set of variables, and complex links between those variables. As my colleagues Jason Weeden and Adam Cohen have been careful to point out in the published papers on this topic, the correlation between involvement in religious groups and reproductive behaviors is only one part of a complex picture. Religious beliefs and involvement in religious groups (two separable things) have been linked to many other features of human cognition and social life (as described in thoughtful analyses by researchers like Pascal Boyer, David Sloan Wilson, Lee Kirkpatrick, Ara Norenzayan, and Jesse Bering, see a few citations below).

To further complicate things, the relationship between IQ and religious beliefs may vary by religious group. My colleague Adam Cohen, who studies the psychology of different religious groups, assures me that Jews are, on average, smarter than Gentiles.  Regis high school was an institution for gifted Catholic teenagers in New York (from which I was expelled, I fear). I am fairly certain that my fellow Catholic students and the Jesuits who taught us had higher IQs than most of the other citizens of New York City, even those who were Jews or atheists (at least on average). When I got older and fell away from the church I don’t believe it was directly caused by any increase in my IQ (supporting Weeden’s theory, the rift came at a time when I was in college, discovering the sinful joys of premarital sex, and incidentally drinking regularly enough to destroy more neural connections than I was building).

Regarding the education-religion link, note that many of the world’s best universities were started by religious groups, and many were seminaries. In other times and places, being highly interested in religion was the main path to higher education. On a related note, Weeden is also careful to note that his data support a link between sexual attitudes and religious attendance among modern Americans.

Link to previous post: Atheistic liberals are more intelligent, but for a funny reason

*Cohen observes he doesn't go to synagogue all that frequently, and claims his IQ is 246 (a team of measurement specialists has been contacted to verify the latter claim)

References/ Suggested readings:

Boyer, P. (2003). Religious thought and behaviour as by-products of brain function. Trends in Cognitive Science, 7, 119–124.

Johnson, D., & Bering, J. (2006). Hand of God, mind of man: Punishment and cognition in the evolution of cooperation. Evolutionary Psychology, 4, 219-233.

Kirkpatrick, L. A. (2005). Attachment, evolution, and the psychology of religion. New York: Guilford.

Li, Y.J., Cohen, A.B., Weeden, J., & Kenrick, D.T. (2010). Mating Competitors Increase Religious Beliefs. Journal of Experimental Social Psychology. In press

Shariff, A. F., & Norenzayan, A. (2007). God is watching you: Priming God concept increases prosocial behavior in an anonymous economic game. Psychological Science,18, 803–809.

Weeden, J., Cohen, A.B., & Kenrick, D.T. (2008).  Religious attendance as reproductive support. Evolution & Human Behavior, 29, 327-334.

Wilson, D. S. (2002). Darwin's Cathedral: Evolution, Religion, and the Nature of Society. Chicago: University of Chicago Press.

For an intelligent take on the psychology of intelligence, see: Miller, G. F. (2000). The mating mind: How sexual choice shaped the evolution of human nature. New York: Doubleday.