Diffusion of responsibility

Diffusion of responsibility is a sociopsychological phenomenon whereby a person is less likely to take responsibility for action or inaction when others are present. Considered a form of attribution, the individual assumes that others either are responsible for taking action or have already done so. The phenomenon tends to occur in groups of people above a certain critical size and when responsibility is not explicitly assigned. It rarely occurs when the person is alone and diffusion increases with groups of three or more.