Nepotism: nature or nurture?


Nepotism is the tendency to give family advantages. It's perfectly natural; or is it? Why are we biased towards some people just because they brought us up? Take grandparents, for example. They give you no evolutionary advantavage, and yet we have a connection to them: why?

Nepotism could be a natural tendency. Your parents are the ones you owe your lifew to, so you should be indebted to them and have a perfectly natural bond. It's also an advantage evolutionary to stay in groups so that you can protect yourself from others. If those groups are people that you'd be connected to anyway, then all the better.

However, nepotism shouldn't be natural. Your parents give you no actual advantage once you can eat and fend for yourself. If you had to fight them, having this tendency would be a massive disadvantage. Also, an uncle or an aunt shouldn't have a connection with you: after all, they've done nothing to help you to survive.

So, what do you think? Do you think that nepotism is nature and evolution or nurture and social pressure? Yes or no? Why or why not?