The largest group (37%) was what I would call “cultural non-believers”, and what they call “academic” or “intellectual atheists”: people who are well-educated, interested in religion, informed about it, but not themselves believers. I call them “cultural” because they are at home in a secular culture which takes as axiomatic that exclusive religious truth claims must be false. Essentially, they are how I imagined the majority readership of Comment is Free’s belief section. They are more than twice as common as the “anti-theists” whose characteristics hardly need spelling out here:
If any subset of our non-belief sample fit the “angry, argumentative, dogmatic” stereotype, it is the anti-theists. This group scored the highest amongst our other typologies on empirical psychometric measures of anger, autonomy, agreeableness, narcissism, and dogmatism while scoring lowest on measures of positive relations with others … the assertive anti-theist both proactively and aggressively asserts their views towards others when appropriate, seeking to educate the theists in the passé nature of belief and theology.
Nonetheless, these people made up only 14% of their sample, and all other research that I know of would place their proportion much lower.
Amanda Marcotte also discusses how the study upends stereotypes:
While atheists have a public image of being dogmatic and belligerent—an image that famous atheists like Bill Maher only end up reinforcing—researchers found that to absolutely not be true. Only 15 percent of non-believers even fit in the category of those who actively seek out religious people to argue with, and the subset that are dogmatic about it are probably even smaller than that. But that doesn’t mean that the majority of non-believers are just sitting around, twiddling their thumbs and not letting atheism affect their worldview. On the contrary, researchers found that the majority of non-believers take some kind of action in the world to promote humanism, atheism or secularism…
While most atheists limit themselves to supporting a more secular society, anti-theists tend to view ending religion as the real goal. While plenty are aggressively angry, researchers point out this isn’t necessarily a bad thing: “For example, many of the Antitheist typology had responded as recently deconverted from religious belief or socially displeased with the status quo, especially in high social tension-based geographies such as the Southeastern United States,” and being combative with believers might help them establish their own sense of self and right to non-belief.