Bystander – A person who is present but not involved: an onlooker or spectator. A bystander, or witness, is someone who sees a situation but may or may not know what to do, may think others will act or may be afraid to do something.
Bystander Effect – The term bystander effect was first coined by Darley and Latané in 1968 as the psychological phenomenon in which someone is less likely to intervene in an emergency situation when other people are present and able to help than when he or she is alone.
Bystander Intervention – In-the-moment interventions where those around an individual or group who are engaging in risky or dangerous behavior, step up and intervene in an attempt to prevent harm.
Bystander Resources – list of training programs and examples of bystander interventions from colleges and universities