Why are we risk averse and risk loving at the same time?

Admit it: we are risk averse. This is evolutionarily advantageous: danger was everywhere back in the jungle, and you'd better choose to play safe to survive.

But interestingly, most people like to gamble. Where there is a small possibility that we get really rich, we are willing to take risk for it. If we think about it, all the entrepreneurs are risk loving -- they are willing to take risk to receive profit. Men are more risk loving than women, which make sense from an evolutionary point of view. It also explains why most entrepreneurs are male. Well, incidentally, the reason why most experts in the world are male is because men are wired in such a way that they can focus on polishing a skill, which is different than they way females are created.

One way to explain this is suing probability weighting -- it has been observed that people tend to over-weigh small chance event: we try very hard, more than necessary, to avoid danger that is extremely unlikely to happen; we also expect extremely unlikely gains to happen more often that they should.

But why? Maybe evolutionary theory is the way to go...