I recently read an article in the magazine Psychology Today  that discusses a phenomenon in social perception called the Doppelgänger Bias .  For starters, a doppelgänger is a non-biologically related look-alike or double of a living person. In books and movies, it is sometimes portrayed as a ghostly or paranormal apparition and usually deemed a harbinger of bad luck. Our prior knowledge of a person -- whether he/she has treated you well or poorly -- determines how you act toward that individual in the future. But research suggests that a person's track record may also affect how you treat people who look like the person in question. In studies headed by Brown University neuroscientist Oriel FeldmanHall, participants played a money-sharing game with several "male partners" whose headshots appeared onscreen. (Players were lead to believe they were dealing with actual people, but the partners were virtual.) As the study participants played, they discovered these ...