Okay. I was wondering about the anthropology, though.Well I recommend that you look into it. Studies on altruism in the animal kingdom from ants and bees to chimps are all freely available. In a social group our welfare is no longer separable from that of the other members. Altruistic behaviour strengthens social bonds as well as increasing survivability for the group.
Again, not anthropology.If you type into your search engine 'the evolution of altruism', or any other such key terms you will find links to thousands of articles.