I was talking about evolutionary psychology there, not taking into consideration behaviours motivated by higher intelligence. Perhaps different behaviours can be placed in a hierarchy, with more complex behaviours in higher levels and primary instincts at the bottom. Sexual urges, for example, would be pretty low on the chart. We're not completely immune to those. It was one of the things I encountered in a book I read about evolution. It said that this is probably how more "altruistic" and less selfish behaviours developed -- a desire to help the species as a whole rather than just the individual self.