Predicting persons' versus a person's goodness: behavioral forecasts diverge for individuals versus populations.

Behavioral forecasts of individuals ("How likely is it a randomly selected person will…") and behavioral forecasts of populations ("What percentage of people will…") are often used interchangeably. However, 6 studies showed that behavioral forecasts of individuals and populations systematically differ. In judgments of morally relevant behaviors, forecasters estimated that a randomly selected individual (e.g., a student) would act more selflessly (e.g., give to charity) than would the population from which the individual was drawn (e.g., the student body). The studies provided consistent support for 1 of 5 possible explanations for the effect, a differential sensitivity to constraints hypothesis. When considering how an individual will behave, people give weight to an individual-level force on behavior: what an individual's moral conscience would lead one to do. When considering a population, forecasters give more emphasis to a group-level force on behavior: social norms and pressures. A final study extended the differential sensitivity to constraints account to forecasts of non-morally relevant behaviors. Individuals were forecast as more likely than populations to perform behaviors that emerge primarily because of an individual-level force-a person's will-but not behaviors that are encouraged by social norms.