The Bystander Effect is the phenomoneon that the more people present, the less likely they are to help a person in distress.
Experiments by Bibb Latane and John Darley show this effect. Their experiments had three situations a subject was put into: alone in a room, room with two other participants, or a room with two people aware of the study. In each room, smoke began to fill the room. Their results were that 75% of participants reported the smoke when they were alone in a room. 38% of subjects who were in a room wth two other subjects reported the smoke. 10% of participants in the room with two others (aware of the study) reported the smoke (two others ignored the smoke). This experiment shows the Bystander Effect that people are less likely to report a distressful situation if they are in the presence of others.
Two theories try to explain the Bystander Effect. First, diffusion of responsibility. When there are other people present, individuals feel less pressue to react. Next, people don't react when in the presence of others because they feel it is socially inappropriate. If others don't take action, individuals feel it is not necessary to take action because no one else before them did.
The Bystander Effect is an aspect of social conformity. Specifically, it relates to the phenomoneon that people are less likely to take action to a distressful situation if they are in the presence of others. This effect was proven by Latane and Darley when they performed experiements that showed the above results. Lastly, this effect is caused by diffusion of responisibility and social norms.
Below is a vido clip that further illustrates the Bystander Effect