Religious 'Nones' are now the largest single group in the U.S.

When Americans are asked to check a box indicating their religious affiliation, 28% now check 'none.'

A new study from Pew Research finds that the religiously unaffiliated – a group comprised of atheists, agnostic and those who say their religion is "nothing in particular" – is now the largest cohort in the U.S. They're more prevalent among American adults than Catholics (23%) or evangelical Protestants (24%).

Back in 2007, Nones made up just 16% of Americans, but Pew's new survey of more than 3,300 U.S. adults shows that number has now risen dramatically.

Researchers refer to this group as the "Nones."