bystander

Bystander refers to a person who is present at an event but does not participate in it. In everyday use, bystanders observe situations from a distance or passively witness others’ actions. In social psychology, the term is often applied to incidents in which help might be offered to someone in need, such as an accident, harassment, or medical distress.

The most studied aspect is the bystander effect, the finding that people are less likely to help when others are present. Explanations include diffusion of responsibility, in which each observer assumes others will intervene, and social influence, where individuals look to others to decide how to act. Situational factors such as ambiguity, perceived danger, and physical crowding also play roles.

Bystander intervention describes acts of helping by people who witness an emergency. A common framework identifies five steps: notice the event, interpret it as an emergency, assume personal responsibility, know how to help, and implement a form of assistance. Training can increase willingness and skill, reducing hesitation in real situations.

Legal and cultural contexts influence helping. Some jurisdictions provide Good Samaritan protections from liability, while others impose limits. Public campaigns and school programs aim to normalize intervention and reduce barriers such as fear of causing harm or making the situation worse.

Research has evolved since the Kitty Genovese case, which popularized the bystander effect; later analyses showed many reports were exaggerated or misinterpreted. Contemporary studies emphasize individual and situational variability, and interventions that promote active helping across diverse contexts.