Created with Sketch. Evolutionary biologist Robert Trivers proposed a number of theories on evolutionary psychology, including why we engage in reciprocal altruism, the nature of sex differences ...

The last five questions are about you, and they'll be used by our research team to better understand how altruism relates to factors like age and gender. When you're done, you'll get your score, learn ...

Experiments show evidence that altruism is hardwired in the brain—and it's pleasurable. Helping others may just be the secret to living a life that is not only happier but also healthier ...