This article is about the psychological phenomenon. In an unrelated use, the term bystander effect is also used in radiobiology to describe the effects of radiation on cells that are adjacent to those directly affected by radiation.

The bystander effect (also known as bystander apathy) is a psychological phenomenon where persons are less likely to intervene in an emergency situation when others are present than when they are alone.

Solitary individuals will typically intervene if another person is in need of help: this is known as bystander intervention. However, researchers were surprised to find that help is less likely to be given if more people are present. In some situations, a large group of bystanders may fail to help a person who obviously needs help. An example which shocked many people is the Kitty Genovese case. Kitty Genovese was stabbed to death in 1964 by a mentally ill man. The murder took place over a period of about thirty minutes, during which at least 38 alleged "witnesses" failed to help the victim. For this reason, the name Genovese syndrome or Genovese effect was used to describe the phenomenon at the time. The death of Deletha Word in 1995 after witnesses failed to thwart her attackers, as well as the James Bulger murder case, may have been other well-publicized cases of the effect.

A 1968 study by John Darley and Bibb Latané first demonstrated the bystander effect in the laboratory. The most common explanation is that, with others present, observers all assume that someone else is going to intervene and so they each individually refrain from doing so. This is an example of how diffusion of responsibility leads to social loafing. People may also assume that other bystanders may be more qualified to help, such as being a doctor or police officer, and their intervention would thus be unneeded. People may also fear "losing face" in front of the other bystanders, being superseded by a "superior" helper ,or offering unwanted assistance. Another explanation is that bystanders monitor the reactions of other people in an emergency situation to see if others think that it is necessary to intervene. Since others are doing exactly the same, everyone concludes from the inaction of others that other people do not think that help is needed. This is an example of pluralistic ignorance.

A victim may be able to reduce the bystander effect by picking a specific person in the crowd to appeal to for help rather than appealing to the larger group generally. This may work better, because it makes a person in the crowd feel personally responsible, instead of being able to diffuse responsibility.

See also

• Conformity
• Milgram experiment

References

• J. M. Darley & B. Latane. (1968). Bystander intervention in emergencies: Diffusion of responsibility. Journal of Personality and Social Psychology 8, 377-383.

• Gladwell, Malcolm. (2000). The Tipping Point: How Little Things Can Make a Big Difference. ISBN 0316316962.

External links

• http://faculty.babson.edu/krollag/org_site/soc_psych/latane_bystand.html
• http://www.psych.nwu.edu/psych/people/faculty/sherman/lecture15/
• http://bama.ua.edu/~sprentic/672%20outline-bystander%20effect.html
• John M. Darley's home page http://www.princeton.edu/~psych/PsychSite/fac_darley.html