Bandwagon Effect

The bandwagon effect is the tendency for people to adopt a belief or behavior because many other people have already adopted it, regardless of their own independent evaluation of the underlying evidence. The name derives from the phrase "jump on the bandwagon," associated with nineteenth century American political campaigning, in which supporters would literally climb aboard a parade bandwagon to signal allegiance to a candidate. The effect has been documented across voting behavior, financial markets, fashion and public opinion, and it is treated in economics and political science as a form of positive feedback in which growing popularity itself becomes a further driver of even greater popularity.