Are religious people less intelligent than atheists?

That's the provocative conclusion of a new review of 63 studies of intelligence and religion that span the past century. The meta-analysis showed that in 53 of the studies, conducted between 1928 to 2012, there was an inverse relation between religiosity -- having religious beliefs, or performing religious rituals -- and intelligence. That is, on average, non-believers scored higher than religious people on intelligence tests.

What might explain the effect?

Scientists behind studies included in the review most often suggested that "religious beliefs are irrational, not anchored in science, not testable and, therefore, unappealing to intelligent people who 'know better.'”

But the researchers who conducted the new meta-analysis say the answer is a bit more complicated. They suspect intelligent people might have less of a "need" for religion.

"Intelligence may also lead to greater self-control ability, self-esteem, perceived control over life events, and supportive relationships, obviating some of the benefits that religion sometimes provides," study co-author Jordan Silberman, a graduate student of neuroeconomics at the University of Rochester, told The Huffington Post in an email.

So if you're a believer, does this mean you're a dope?

"I'm sure there are intelligent religious people and unintelligent atheists out there," Silberman said in the email. "The findings pertain to the average intelligence of religious and non-religious people, but they don't necessarily apply to any single person. Knowing that a person is religious would not lead me to bet any money on whether or not the person is intelligent."

The researchers acknowledge the limitations of the meta-analysis. It did not look at type of religion, for example, or at the role culture might play in the interaction between religiosity and intelligence.

In addition, The Independent pointed out that the researchers used a narrow definition of intelligence. In the paper, intelligence is defined as “the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly, and learn from experience." This excludes other forms of intelligence, like creative and emotional intelligence.