Do car insurance companies really lower rates for females while charging more for males?

I was told by a friend of mine that car insurance companies tend to be cheaper for females while males have to pay more.

I remember thinking that this is very freaking sexist. This is basically the insurance companies saying that men can't be trusted when operating a motor vehicle and are prone to accidents. If this is true, is this because they assume only men engage in street racing and reckless driving?

Now that I think about it. This is sort of sexist toward women too, because they're assuming they're perfectly safe drivers. Interesting, when something is sexist toward one gender, it affects the others indirectly or directly.