After much consideration, the only stereotype I have found that consistently works in most situations is: People do lots of things. Most of them are crazy. And the more people there are, the more crazy the things are in general.

Well, the fact is that human interactions are rarely reductionist or logical. Courtship and dating are especially that way. You have social expectations, hormones, and so forth that together more or less create these elaborate emergant ritualistic dances where nothing is what it seems.