Millennials: The least religious generation

The researchers -- including Ramya Sastry from SDSU, Julie J. Exline and Joshua B. Grubbs from Case Western Reserve University and W. Keith Campbell from the University of Georgia -- analyzed data from 11.2 million respondents from four nationally representative surveys of U.S. adolescents ages 13 to 18 taken between 1966 and 2014.

Recent adolescents are less likely to say that religion is important in their lives, report less approval of religious organizations, and report being less spiritual and spending less time praying or meditating. The results were published this month in the journal PLOS One.

"Unlike previous studies, ours is able to show that millennials' lower religious involvement is due to cultural change, not to millennials being young and unsettled," said Twenge, who is also the author of "Generation Me."

"Millennial adolescents are less religious than Boomers and GenX'ers were at the same age," Twenge continued. "We also looked at younger ages than the previous studies. More of today's adolescents are abandoning religion before they reach adulthood, with an increasing number not raised with religion at all."

Compared to the late 1970s, twice as many 12th graders and college students never attend religious services, and 75 percent more 12th graders say religion is "not important at all" in their lives. Compared to the early 1980s, twice as many high school seniors and three times as many college students in the 2010s answered "none" when asked their religion.

Compared to the 1990s, 20 percent fewer college students described themselves as above average in spirituality, suggesting that religion has not been replaced with spirituality.

"These trends are part of a larger cultural context, a context that is often missing in polls about religion," Twenge said. "One context is rising individualism in U.S. culture. Individualism puts the self first, which doesn't always fit well with the commitment to the institution and other people that religion often requires. As Americans become more individualistic, it makes sense that fewer would commit to religion."