Altruism is helping without a benefit and sometimes at a risk to one’s self. Recent research that found killer sharks ...

Puzzled by the behavior, Darwin described altruism in animals as a type of evolutionary snag. In 1964, another naturalist proposed an explanation — animals were more likely to share with others who ...

The findings suggest that the instinct to help others in distress could be deeply rooted in mammalian evolution, challenging long-standing ideas about altruism in the animal kingdom.