The first two examples are human-centric, as they have a greater bearing on the initial question: reciprocal exchanges and breastfeeding. In the former case—reciprocal altruism—two individuals will ...

Altruism is defined as the unselfish concern for other people—doing things simply out of a desire to help, not because you ...

What do mutual grooming, politeness, priestly celibacy, military heroism, car insurance, and overwork have in common? All are probable examples of the recently discovered evolutionary mechanism called ...

Though we don’t live in zoos, we often behave like animals. So many of our instincts are derived from our animal counterparts. Take the various forms of altruism as an example. In the animal kingdom, ...