The threefold cord -- Helping in nonemergency situations -- Norms and behavior -- Characteristics of emergencies and the intervention process -- Social determinants of bystander intervention I : the social influence process -- Where there's smoke ... -- The bystander and the victim -- The bystander and the thief -- Motivation and perception in emergencies -- Social determinants of bystander intervention II : diffusion of responsibility -- An epileptic seizure -- Personality, socioeconomic class, and helping in emergencies -- Man's strength to comfort man's distress.