"I kept reading things like, "The purpose of such-and-such a behavior is so-and-so"-in other words, the assumption that every behavior has a purpose important to survival. Let's face it, some behaviors don't; if they're genetic at all, they only have to stay out of the way of survival to continue. Then, just a year or so ago, I read one of Stephen Jay Gould's books in which he says much the same thing. I was relieved to see a biologist write that some things-physical characteristics or behaviors-don't kill you or save you; they may be riding along with some important genetic characteristic, though they don't have to be."