And are there more types than these? This is apparently from sociological research out of the University of Tennessee, but I'm reporting from the Salon article. The researchers identified six categories of non-believers in the U.S., with estimates of their relative size.
1. Intellectual Atheist/Agnostic. By far, the most common kind of non-believer, at nearly 38 percent. This group enjoys intellectual discourse, and while they’re often very certain about their beliefs, they’re not belligerent about it. These types often get mistaken for dogmatic atheists, however, because they have a tendency to join skeptic’s groups or otherwise find avenues to discuss non-belief with others. However, as researchers note, these non-believers “associate with fellow intellectuals regardless of the other’s ontological position." They like debating religion, but aren’t particularly interested in chasing down believers to give them a hard time.
2. Activist. This group also gets commonly accused of being dogmatic, but like the intellectual atheist, while they’re firm in their beliefs, they’re intellectually flexible and don’t prioritize attacking believers. Instead, they are motivated by a strong sense of humanist values to make change in the world, often making related issues—such as feminism, gay rights, or the environment—a priority over simply advocating atheism. They are the second biggest sub-category of non-believers, making up 23 percent of non-believers.
3. Seeker-Agnostic. This group, which makes up 7.6 percent of non-believers, are unlikely to be as critical of religion as most other groups. They prioritize not-knowingness. If you ever come across people saying, “I don’t know, but neither do you!” regarding religious belief, you’re dealing with a seeker-agnostic. They don’t really believe in anything, but they are uncomfortable committing to non-belief completely.
4. Anti-Theist. This group tends to get conflated with all atheists by believers, but they only constitute 15 percent of non-believers. Like the Intellectual Atheists, they like to argue about religion, but they are much more aggressive about it and actively seek out religious people in an effort to disabuse them of their beliefs. While most atheists limit themselves to supporting a more secular society, anti-theists tend to view ending religion as the real goal.
5. Non-Theist. They don’t believe in any gods, but don’t think about those who do very often. In such a religious society, simply opting out of caring much about religion one way or another is nearly impossible, which is why this group is only 4.4 percent of non-believers. “A Non-Theist simply does not concern him or herself with religion,” researchers explain. In some skeptical/atheist circles, this group is disparagingly referred to as “shruggies,” because they simply shrug when asked their opinion on religion.
6. Ritual Atheist/Agnostic. This group, making up 12.5 percent of atheists, doesn’t really believe in the supernatural, but they do believe in the community aspects of their religious tradition enough to continue participating. We’re not just talking about atheists who happen to have a Christmas tree, but who tend to align themselves with a religious tradition even while professing no belief. “Such participation may be related to an ethnic identity (e.g. Jewish),” explain researchers, “or the perceived utility of such practices in making the individual a better person.”