T
hree myths about morality remain alluring: only humans act on moral emotions, moral precepts are divine in origin, and learning to behave morally goes against our thoroughly selfish nature.
Converging data from many sciences, including ethology, anthropology, genetics, and neuroscience, have challenged all three of these myths. First, self-sacrifice, given the pressing needs of close kin or conspecifics to whom they are attached, has been documented in many mammalian species—wolves, marmosets, dolphins, and even rodents. Birds display it too. In sharp contrast, reptiles show no hint of this impulse.
Second, until very recently, hominins lived in small groups with robust social practices fostering well-being and survival in a wide range of ecologies. The idea of a divine lawgiver likely played no part in their moral practices for some two million years, emerging only with the advent of agriculture and larger communities where not everyone knew everyone else. The divine ...