A new Pew Research Center survey finds that as the world becomes more secular, more people are identifying as Christians or unaffiliated with any religion.
While those numbers are still fairly small (around 2% and 6% of Americans in their early 20s, respectively), they represent a big shift from the days when most people thought of themselves as religiously observant.
The survey also found that about 6% now say they are religious, up from 5% who said that in 2010.
There is also a shift among people who identify as atheists or agnostics: About 10% say they have no religious affiliation, up slightly from 8% a decade ago.
Those numbers have also grown in recent years.
The last time Pew tracked this issue was in 2014, when it asked people how much they knew about religion.
More than half (54%) said they knew at least a little about religion, up 2 points from 2015.
Those figures have been stable over time, however.
In the past, Pew found that roughly one-third of Americans said they had no religion.
Now that’s less than half.
The Pew survey also looked at religious and non-religious Americans by their faith and their overall religious affiliation.
About four in 10 Americans who identified as Christian, about one-quarter of whom were unaffiliated, reported being religious.
Among those who identified with another religion, more than half reported being agnostic, or saying they don’t believe in a god or pantheon.
About three-quarters of Americans identified as Catholic, up 7 points from 2014.
More Americans are now identifying as religiously unaffiliated than religiously affiliated, Pew finds.
In 2010, roughly seven in 10 unaffiliated Americans said that they had “no religion,” and about a third (36%) were religiously unafflicted.
The rise in religious affiliation may have something to do with the changing demographic landscape, says Michael McDonald, a sociologist at the University of Illinois.
In more religiously-segregated communities, religious groups tend to have a larger presence.
In urban areas, for example, many of the same people who were once unaffiliated may now identify as Christian or unafflagged.
More religiously diverse communities have also seen a rise in churchgoing, McDonald says.
More Americans now say religion is a big part of their lives, even if they are not religious.
Pew found about half of those who reported no religion (46%) say religion plays a big role in their lives.
About one in five say religion has a big impact on their lives (17%).
And about four in ten Americans (42%) say their religious beliefs are important or very important in their daily lives.
That compares with about one in four in 2010, when about half (53%) of those saying religion had a big influence on their daily life.
“The rise of religious affiliation is not surprising, given that we are increasingly secular in this country,” says McDonald.
“But it is a new phenomenon, and we need to understand the factors that are at play in how that happens.”