Research participants who had played a 5-minute computer game using a Superman avatar were subsequently kinder to other people, and those who had played as the evil Voldemort were less kind, say Gunwoo Yoon and Patrick T. Vargas of the University of Illinois at Urbana-Champaign. After the computer game, the participants were instructed to provide an unspecified amount of chocolate and hot chili sauce to other people who they believed would be required to eat it all (untrue); those who had been “Superman” provided about twice as much chocolate as chili sauce, while those who had been “Voldemort” did the reverse.
SOURCE: Know Thy Avatar: The Unintended Effect of Virtual-Self Representation on Behavior