Estimating the number of atheists in the U.S. is complicated. Some adults who describe themselves as atheists also say they believe in God or a universal spirit. At the same time, some people who identify with a religion (e.g., say they are Protestant, Catholic or Jewish) also say they do not believe in God.
But one thing is for sure: Along with the rise of religiously unaffiliated Americans (many of whom believe in God), there has been a corresponding increase in the number of atheists. As nonbelievers and others gather in Washington, D.C., for the “Reason Rally,” here are key facts about atheists and their beliefs:
1The share of Americans who identify as atheists has roughly doubled in the past several years. Pew Research Center’s 2014 Religious Landscape Study found that 3.1% of American adults say they are atheists when asked about their religious identity, up from 1.6% in a similarly large survey in 2007. An additional 4.0% of Americans call themselves agnostics, up from 2.4% in 2007.
2Atheists, in general, are more likely to be male and younger than the overall population; 68% are men, and the median age of atheist adults in the U.S. is 34 (compared with 46 for all U.S. adults). Atheists also are more likely to be white (78% are Caucasian vs. 66% for the general public) and highly educated: About four-in-ten atheists (43%) have a college degree, compared with 27% of the general public.
3Self-identified atheists tend to be aligned with the Democratic Party and with political liberalism. About two-thirds of atheists (69%) identify as Democrats (or lean in that direction), and a majority (56%) call themselves political liberals (compared with just one-in-ten who say they are conservatives). Atheists overwhelmingly favor same-sex marriage (92%) and legal abortion (87%). In addition, three-quarters (74%) say that government aid to the poor does more good than harm.
4Although the literal definition of “atheist” is “a person who does not believe in the existence of a god or any gods,” according to the Merriam-Webster dictionary, 8% of those who call themselves atheists also say they believe in God or a universal spirit. Indeed, 2% say they are “absolutely certain” about the existence of God or a universal spirit. Alternatively, there are many people who fit the dictionary definition of “atheist” but do not call themselves atheists. About three times as many Americans say they do not believe in God or a universal spirit (9%) as say they are atheists (3%).
5Unsurprisingly, more than nine-in-ten self-identified atheists say religion is not too or not at all important in their lives, and nearly all (97%) say they seldom or never pray. At the same time, many do not see a contradiction between atheism and pondering their place in the world. Three-in-ten (31%) say they feel a deep sense of spiritual peace and well-being at least weekly. A similar share (35%) often thinks about the meaning and purpose of life. And roughly half of all atheists (54%) frequently feel a deep sense of wonder about the universe, up from 37% in 2007. In fact, atheists are more likely than U.S. Christians to say they often feel a sense of wonder about the universe (54% vs. 45%).
6In the 2014 Religious Landscape Study, self-identified atheists were asked how often they share their views on God and religion with religious people. Only about one-in-ten atheists (9%) say they do at least weekly, while roughly two-thirds (65%) say they seldom or never discuss their views on religion with religious people. By comparison, 26% of those who have a religious affiliation share their views at least once a week with those who have other beliefs; 43% say they seldom or never do.
7Virtually no atheists (1%) turn to religion for guidance on questions of right and wrong, but increasing numbers are turning to science. About a third of atheists (32%) say they look primarily to science for guidance on questions of right and wrong, up from 20% in 2007. A plurality (44%) still cite “practical experience and common sense” as their primary guide on such questions, but that is down from 52% in 2007.
8Americans like atheists less than they like members of most major religious groups. A 2014 Pew Research Center survey asked Americans to rate groups on a “feeling thermometer” from zero (as cold and negative as possible) to 100 (the warmest, most positive possible rating). U.S. adults gave atheists an average rating of 41, comparable to the rating they gave Muslims (40) and far colder than the average given to Jews (63), Catholics (62) and evangelical Christians (61).
9About half of Americans (51%) say they would be less likely to support an atheist candidate for president, more than say the same about a candidate with any other trait mentioned in a Pew Research Center survey – including being Muslim. This figure, while still high, has declined in recent years – in early 2007, 63% of U.S. adults said they would be less likely to support an atheist presidential candidate. There are currently no self-described atheists serving in Congress, although there is one House member, Kyrsten Sinema (D-Ariz.), who describes herself as religiously unaffiliated.
10About half of Americans (53%) say it is not necessary to believe in God to be moral, while 45% say belief in God is necessary to have good values, according to a 2014 survey. In other wealthy countries, smaller shares tend to say that a belief in God is essential for good morals, including just 15% in France. But in many other parts of the world, nearly everyone says that a person must believe in God to be moral, including 99% in Indonesia and Ghana and 98% in Pakistan.
Note: This post was originally published on Nov. 5, 2015, as “7 facts about atheists,” and updated on June 1, 2016.