Millennials Americans roughly between ages 18 and 30 were not included in the study because, Schwadel said, it's too soon to tell if they will settle on a religious identity.
Schwadel, whose study is published in the August edition of the journal Social Forces, found a clear historical shift.
"Americans born in the late 1920s and '30s who graduated from college were twice as likely to drop out of religion than people who didn't graduate from college," he said. The postwar baby boomers proved to be "the last holdout of the church dropouts." For boomers, "a college degree was still associated with a higher likelihood of leaving religion."
However, for the generation born in the 1960s, there's no difference between those who did and those who did not go to college in their likelihood of religious affiliation. Now, for America's middle-aged adults who were born in the 1970s, "those without a college education are the most likely to drop out."
In other words, a college degree used to mean people were more likely to lose religion. Now, some people are losing religion whether they went to college or not but it's especially true for those who didn't go to college.
Although the study does not examine the reasons for this shift, Schwadel observed:
• You can find God on the quad. Campus life has also changed and now offers "a lot of room and opportunity for religious connection. The social networks are wider."
• College is more widely accessible, no longer a bastion of the cultural elite. What's more, cultural trends that started with the elite including quitting organized religion have become more widespread. "Secularization has lost its elitism moving across all social classes."
• Churches have changed, too. As more college-educated people affiliate with churches, those without degrees can feel uncomfortable. "I know from my other research that people want to go to church with people like themselves."