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 ...

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 ...

There’s a great value in being precise when it comes to communication (if you want your message to be understood as you intended it, anyway; when clarity isn’t the goal, by all means, be imprecise).