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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. The antonym of the term is civil courage.


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 serial rapist and murderer. 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. (There is controversy over whether any of the alleged witnesses were in fact aware of the attack on Ms. Genovese. The claim that they were is traceable to newspaper coverage at the time of the attack which does not quote those witnesses, and many of them deny having been aware of any of the events 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. They ran some simple studies such as the following. A subject is placed alone in a room and is told he can communicate with other subjects through an intercom. In reality, they are all confederates who have been recorded on an audio tape. While they are all talking, one of them suddenly pretends he is having a seizure and the communications link goes down. The study found that how long the subject waits before alerting the experimenter varies inversely with the number of other subjects. In some cases, the subject never told the experimenter.

The most common explanation of this phenomenon 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 and social proof.

A victim may be able to counter 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 places all responsibility on that specific person, instead of allowing it to diffuse; it counters pluralistic ignorance by showing that all bystanders are indeed interested in helping; and it kicks in social proof when one or more of the crowd steps in to assist.


The following scenario demonstrates the bystander effect. A man out walking alone early in the morning who sees smoke rising from the window of a house may well investigate further, to ascertain whether there was indeed a fire and whether anyone was in need of help. However, if a number of other people are also walking by and ignoring the smoke, the man may be more likely to conclude that there was no emergency, and ignore the situation.

See also


  • 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

he:פיזור אחריות

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