Yesterday my colleague Larry Iannaccone, the world’s leading expert on the Economics of Religion, gave a provocative lecture on Christian fundamentalism. His thesis: Almost all the stereotypes about this group are false. Now I’m one of those people who believes that stereotypes are usually true statistical generalizations, so naturally I was skeptical.

To check my suspicions, I turned to the General Social Survey. It’s got an excellent way to identify Christian fundamentalists. The question BIBLE asks “Which of these statements comes closest to describing your feelings about the Bible?,” and offers three responses:

1. “The Bible is the actual word of God and is to be taken literally, word for word.”

2. “The Bible is the inspired word of God but not everything in it should be taken literally, word for word.”

3. “The Bible is an ancient book of fables, legends, history, and moral precepts recorded by men.”

I think it’s fair to call people fundamentalists if and only if they pick response #1.

Now let’s consider a few of the stereotypes that Larry questions.

1. “Fundamentalists are anti-gay.” Larry admits that fundamentalists think that homosexuality is morally wrong, and oppose “special treatment” for gays. But the data say more. The GSS asks “Suppose this admitted homosexual wanted to make a speech in your community. Should he be allowed to speak, or not?”

59% of fundamentalists say No; 73% of non-fundamentalists say Yes.

2. “Fundamentalists are ignorant.” Larry claims that fundamentalists actually have the average education level. But the GSS says they’ve got 1.9 fewer years of education. They also score markedly lower on the GSS’s short IQ test.

3. “Fundamentalists are anti-science.” The GSS asks whether “We trust too much in science and not enough in religious faith.” 55% of fundamentalists agree or strongly agree, versus 21% of non-fundamentalists.

4. “Fundamentalists support traditional gender roles.” The GSS asks “Do you approve or disapprove of a married woman earning money in business or industry if she has a husband capable of supporting her?” Here, Larry seems to be on stronger ground: 75% of fundamentalists approve. But relatively speaking, the stereotype works, because 85% of non-fundamentalists approve.

Bottom line: Larry hastily dismisses a stereotype that is basically sound. Critics of fundamentalism may be exaggerating, but the patterns they point to are real.