It turns out colleges aren't actually atheist factories

“The core finding is that the association between graduating from college and religious disaffiliation has changed drastically across generations,” said Philip Schwadel, the study’s author and a professor at the University of Nebraska-Lincoln. For people who were born in the 1920s and ’30s, the godless-college-grad stereotype is somewhat true: They were twice as likely as their uneducated peers to be religionless, not identifying with a particular church or synagogue or other religious institution.

But over time, that trend changed. “For those people who were born in the 1960s, there’s really no difference between the college-educated and the non-college-educated in terms of their likelihood of disaffiliating from religion,” Schwadel said. “And for those born in the 1970s, it’s actually the non-college-educated who are relatively likely to disaffiliate.”

This may have happened for a few reasons, Schwadel said. “The growth in college education may have led to a different population of people going to college.” In the 1920s, only elites attended universities; especially at a time when religiosity was almost uniformly part of American life, it makes sense that this very small group of top intellectuals were the most likely to reject religion. Now that higher education has gotten somewhat more economically diverse and a lot more widespread, though, it seems natural that intellectual diversity at the university level has grown, too.