Impact Bias

Impact bias is the tendency to overestimate both the intensity and the duration of one's own future emotional reactions to upcoming events, whether positive or negative, compared with how those events are actually experienced once they occur. The psychologists Daniel Gilbert and Timothy Wilson, along with colleagues, documented the effect across a range of studies in the affective forecasting research program they developed beginning in the late 1990s, including findings that people consistently overpredicted how devastated they would feel after a romantic breakup or how elated they would feel after a desired outcome such as a promotion, relative to their actual reported feelings afterward. A key proposed cause of the bias is a failure to anticipate psychological coping processes, sometimes called immune neglect, through which people adapt to both good and bad events more quickly than they predict they will.