Kin selection is a type of natural selection that favors behaviors which help relatives, thus enhancing the reproductive success of shared genes. This concept highlights how altruistic behaviors, where individuals act to benefit others at a personal cost, can evolve because they increase the chances of survival and reproduction of genetically related individuals. It connects to parental investment, as those who invest in their offspring increase the likelihood of passing on their genes, and to social networks, where cooperation among kin can strengthen group bonds and resource sharing.