Psychopathy is characterized by varying blends of certain personality traits, which may include egocentricity, manipulativeness, superficial charm, high stress tolerance, lack of fear, lack of empathy and lack of guilt or remorse. The study involved 111 college students — 64 percent women — who were photographed in their everyday attire. Researchers then had each subject wash off any makeup and change out of his or her own clothes into a t-shirt and sweatpants. Subjects with long hair were asked to pull it back into a ponytail. All subjects were then photographed in this unadorned state.