Is aggression the key? Biological theorists believe that heightened feelings of aggression and impulsivity, produced by low serotonin activity, are key factors in suicide. In 2007, professional wrestling champion Chris Benoit (right) killed his wife and son and then hanged himself, a tragedy that seemed consistent with this theory. In addition, toxicology reports found steroids, drugs known to help cause aggression and impulsivity, in Benoit’s body.