Over most of the past century, researchers have been trying to determine whether there's any link between religion and intelligence. The studies haven't all come to the same conclusion, but a group of researchers led from the University of Rochester decided to look at a large number of them combined to see their results — and they found that most studies pointed to the same thing: that highly intelligent people tend to be less religious, and that highly religious people tend to be less intelligent. At least, that seems to hold true when it comes to the traditional definition of "analytic intelligence," which focuses on puzzle solving, learning, and abstract thinking.

"This relation is not new."

To reach their conclusions, Zuckerman's research team analyzed 63 previously published works that compared religion and intelligence. The vast majority of those — 53 in total — found the two had an inverse relationship. To the research team's leader, Miron Zuckerman, the common finding doesn't come as a surprise. "You have to realize that this relation is not new," Zuckerman told The Verge. "Studies from 1928 found [this]."

Even so, the reason for the link remains unclear. Zuckerman and his team can't say for certain why it occurs either, but they theorize that high intelligence may drive people away from religious behaviors. They pose three major possibilities for why that might be happening: First, intelligent people have been found to be less likely to conform to social pressures, such as religious rhetoric. Second, intelligent people tend to prefer analytic — as opposed to intuitive — thinking, making them more likely to look for scientific evidence. And third, they think that more intelligent people simply may not need the benefits that come alongside religion, such as help with self-regulation and self-improvement.

But despite the researchers' speculation on how intelligence and religious beliefs interact, the team notes that the two don't necessarily have a direct relation. They're both correlated — and they can seemingly predict one another — but that doesn't mean that they strictly affect one another. Zuckerman says that none of the studies he looked at suggested that the two were directly related, and such a finding wasn't in the scope of his study either.

The review has a heavily Western skew

This latest analysis isn't perfect though: the review doesn't look at any studies written in other languages, it heavily focuses on Western cultures, and it primarily gauges intelligence by IQ tests and GPAs, which may not factor in other theorized types of non-analytic intelligence. Zuckerman thinks that the work done so far has been important regardless. "People used to think the relation was trivial or very small," he notes. Now, he says, "most people that are currently working" recognize that something's there — even if they're not sure why.