The third-person effect phenomenon, also called the third-person perception, was first conceptualized in 1983 by sociologist W. P. Davison. The third-person effect is the idea that individuals tend to believe that others are more affected by media messages than they themselves are. While the theory applies to many types of media messages, it can be particularly applicable to some messages that are important in health communication and other forms of risk communication. For example, an individual might assume that advertising about a new pharmaceutical product or something harmful like tobacco has strong effects on others but not on themselves.

Davison had been involved in psychological operations during World War II, and the third-person hypothesis appears to have come out of situations he encountered during that time. ...