Researcher Will Gervais, a psychology graduate student, said the goal of the study was to determine why people believe in God to varying degrees.
He said the study suggests people who process information in a deliberate or analytical way are not as religious as people who are intuitive thinkers and use fast mental shortcuts.
About 650 participants from Canada and the U.S. rated their religious beliefs after doing problem-solving tasks and experiments, said Gervais, who co-authored the study that was published Friday in the journal Science.
Groups that performed tasks designed to trigger analytical thinking rated their belief in God as less than those who didn't.
For example, a group that played a game with words such as analyze, ponder and rational said their belief in God was lower than those who were given a different set of words, including shoe, blue, paper and retrace.
A group of participants that looked at a statue titled The Thinker, depicting a man in a ponderous pose, also rated their religious beliefs as lower than a control group that viewed a different work of art, Gervais said.
And participants who were required to fill out a questionnaire with difficult-to-read font said their religious beliefs were lower than a control group whose questionnaire was easy to read.
"I think one important caveat to our studies is our findings don't have much to say about these long-standing debates about the inherent rationality or worth or truth about religious beliefs," said Gervais.
"Instead, we're trying to describe one factor that might influence where people stand on those debates."
John Stackhouse, a professor of theology and culture at Regent College in Vancouver, said the findings are interesting, but he argued the analytical thinkers' scores didn't drop significantly enough to conclude that people can't be both analytical and religious.
Stackhouse said it would be a mistake to use the results to suggest analytical thinking supports atheism and intuitive thinking supports a belief in the supernatural.
"In other words, smart people, scientific people, rational people disbelieve and dumb intuitive enthusiasts believe," said Stackhouse, who reviewed the study.
"In fact, what analytical people are doing is qualifying their belief when they are given the occasion to rationally reflect upon it."
He said the history of Christianity, for example, is filled with powerful thinkers warning believers against both a mindless type of enthusiasm and a rational fanaticism that is closed to rational reflection.
Historical figures such as Isaac Newton and Galileo who believed in the supernatural would have scored very high on such a study, Stackhouse said.
Even C.S. Lewis, who wrote the classic "Chronicles of Narnia" and was a strong believer, lashed out at God in his classic "A Grief Observed," after his wife died of cancer, Stackhouse noted.
"He published his testimony about how difficult it is to believe in God when your heart is broken and your world is collapsing."