With special reference to human relationships: A 10-stage theory by Hing Keung Ma,  Frontiers of Public Health, Oct. 2017:

“A 10-stage theory of altruism with special reference to human relationships is proposed. The affective, cognitive, and relationship aspects of each stage are delineated in details. There are two developmental principles of altruism. The first principle states that the development of altruism follows the 10-stage theory and moves from Stage 1: Egoism toward the higher stages of altruism slowly. The second developmental principle states that the taxonomy of human relationships is valid at any stage of altruism development. In other words, people at any stage of altruism are more altruistic toward their kin and mate, and then close friends, extended family members, and so on. They are least altruistic toward enemies and members of non-human species.”