The factors driving the growth of religious "nones" in the U.S.

The share of Americans who do not identify with a religious group is surely growing: While nationwide surveys in the 1970s and ’80s found that fewer than one-in-ten U.S. adults said they had no religious affiliation, fully 23% now describe themselves as atheists, agnostics or “nothing in particular.”

But there are differing ideas about the factors driving this trend – and its implications for society. While it appears the U.S. is becoming less religious, some contend that’s not necessarily the case. Instead, they say, the growth of the “nones” may simply indicate that people who are not religious are becoming more forthright and willing to say they have no religious affiliation, perhaps because being a “none” has become more socially acceptable.

Do survey data support this notion? The answer is yes – but only partly. Two, or even three, closely related things seem to be going on. Americans who are not religiously active and who don’t hold strong religious beliefs are more likely now than similar people were in the past to say they have no religion. But that’s not the whole story, because the share of Americans with low levels of religious commitment (on a scale combining four common measures) also has been growing.