Pioneer Woman writes "Researchers at Hebrew University in Jerusalem have found a link between a gene called AVPR1a and ruthless behavior. These findings come from an economic exercise called the 'Dictator Game' that allows players to behave selflessly, or like national dictators and 'little Hitlers' found in workplaces the world over. The team decided to look at AVPR1a because it is known to produce receptors in the brain that detect vasopressin, a hormone involved in 'prosocial' behavior. Researchers tested DNA samples from more than 200 student volunteers, before asking the students to play the game that measured their altruism. There was no connection between the participants' gender and their behavior but there was a link to the length of the AVPR1a gene."