So I'll bet most of you have heard the joke that goes, "There are 10 types of people in the world, those who understand binary and those who don't." If not, you've surely heard someone begin a sentence with the phrase "There are two kinds of people..."
In my (definitely not humble) opinion, the most fundamental division into two groups--once you get past obvious biological ones like "male" and "female"--is this: whether or not a person is interested in controlling the behavior of others that is irrelevant to hir own life. That is, does Alice care whether Bob and Carl--who she has never met and who live in a different city--are sleeping together? If yes, she wants to control others' irrelevant behavior.
The controlling group shows up in all sorts of issues; religion (how does it affect you if I go to Hell, exactly?) and sex (what business is it of yours if two women are sleeping together?) are of course the big ones, but there's also drugs (as long as I show up to my job sober and prepared, what I ingest on the weekends is not relevant) and stuff like the ideological purity of some feminists (I wear skirts because I like them, so you and the patriarchy can kiss my ass). Anyone who talks about "family values" must be suspected of belonging to that group.
Personally I think the world would be a much better place if there were fewer people who felt this inexplicable urge to make other people miserable.