Researchers have identified a gene that may influence altruism, reports the BBC. Test subjects who had the choice of keeping money or giving it away were 50% more likely to give it away if they had a more active version of the gene AVPR1a. The gene is linked to arginine vasopressin, a hormone involved in social bonding.
Humans aren’t alone in their altruism, say researchers, who point out that vasopressin plays a similar role in voles. This suggests that altruism evolved very early in the evolution of mammals. Because society is becoming "increasingly complicated, it's probably more important to be altruistic and co-operative than it was in our ancestral history," concluded one scientist.