Scientists Mapped the Altruism Center of the Brain.

Scientists from the Duke University Medical Center claimed that they have found the "altruism" center of the brain:

Scientists say they have found the part of the brain that predicts whether a person will be selfish or an altruist.

Altruism - the tendency to help others without obvious benefit to oneself - appears to be linked to an area called the posterior superior temporal sulcus.

Using brain scans, the US investigators found this region related to a person's real-life unselfish behaviour.

Link - via Anthropology.net