According to social psychologists john darley and bibb latané, the bystander effect is due less to apathy and more to "" that makes people feel unable to respond to the emergency.

diffusion of responsibility and pluralistic ignorance

Psychologists John Darley and Bibb Latane believes that the more bystanders are in the emergency situation, the less likely someone will intervene. They hypothesized that this diffusion of responsibility is due to the bystanders’ expectations and assumption that someone in the crowd is going to volunteer. It also proposes this phenomenon is more likely to occur in larger groups versus smaller groups. Pluralistic ignorance is demonstrated by bystanders getting the feel of what others are feeling about the situation. How they will react will then be based on other’s reactions.

answer; the trial de novo

answer; ratification;