Illusory correlation in impression formation: Variations in the shared distinctiveness effect as a function of the distinctive person's age, race, and sex.

Illusory correlation research has identified two factors that lead subjects to overestimate the relationship between particular categories of people and particular types of behavior: associative connections and shared infrequency. Three studies examined the nature of illusory correlation effects when both of these factors operated simultaneously. The results were consistent with previous shared infrequency effects only when infrequency and associations acted in concert. When undesirable behaviors were both infrequent and also associatively linked to a stimulus person's demographic group, there was an illusory correlation between membership in an infrequently appearing group and performance of infrequent, undesirable behaviors. More specifically, stimulus persons who were black, old, or of the opposite sex from the subject were rated more negatively when their demographic group appeared infrequently. Different illusory correlations were obtained when infrequency and associative links acted in opposition, undesirable behaviors being infrequent and desirable behaviors being associatively linked. Under these conditions, associative links overrode infrequency, and there was an illusory correlation between membership in an infrequently appearing group and performance of associatively linked, albeit frequent, desirable behaviors. More specifically, stimulus persons who were white, young, or of the same sex as the subject were rated more positively when their demographic group appeared infrequently.