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How Not To Interpret That Religion and IQ Study


A new paper in Personality and Social Psychology Review continues to generate some buzz since the media reported on it earlier this week. The authors conducted a “meta-analysis” (essentially a combination of lots of past studies) to show that there is a moderately negative correlation (r = -0.24) between religious belief and IQ among individuals. In other words, the smarter a person is, the less likely he is to have a strong religious faith.

The study itself is careful and dispassionate, but the reaction from the atheist corner of the Internet has been predictable: If smarter people tend to be atheists, then atheism is probably “correct,” right?

No. Read the full study, which discusses several competing theories for why the negative correlation exists. Let me give my own two cents as to why correlating various beliefs with IQ cannot tell us whether those beliefs are true.

As long as smarter people are more likely to even question traditions such as religious belief, then full-blown rejection of religion will almost inevitably be correlated with higher IQ, even if a majority of smart people still affirm religious belief.

I elaborated on this point a few years ago in The American, AEI’s magazine:

Let’s say that the bottom half of the IQ distribution never questions the religion of their upbringing, while the top half is skeptical. Now, just among that skeptical top half, let’s say that 80 percent end up affirming their faith and remain religious, while the rest reject faith and become atheists.

Religion would seem to be the clear choice of smart people in this hypothetical example, but there would still be a positive correlation between IQ and atheism. The correlation exists not because smart people have necessarily rejected religion, but because religion is the default position for most of our society.

This same principle works in places where the default and iconoclastic beliefs are reversed. Japan, for example, has no tradition of monotheistic religion, but the few Japanese Christians tend to be much more educated than non-Christians in Japan.

Simply put, we can’t solve philosophical disputes by appealing to the higher average IQ of one side or the other.