Diffusion of responsibility occurs when people who need to make a decision wait for someone else to act instead. The more people involved, the more likely it is that each person will do nothing, believing someone else from the group will probably respond.
Psychologists John Darley and Bibb Latané set up an experiment where a distress call made it appear that a person nearby had suffered an injury. When subjects heard the cry, and thought they were the only ones who heard it, 85% of them helped. But if subjects thought there was another person who heard the call too, only 62% helped. And if subjects thought that four other people also heard the cry for help, just 31% took action.
Diffusion of responsibility makes people feel less pressure to act because they believe, correctly or incorrectly, that someone else will do so. And, when we don’t feel responsible for a situation, we feel less guilty when we do nothing to help.
So, in this way, diffusion of responsibility keeps us from paying attention to our own conscience.