Social "facilitation" as challenge and threat.

The authors conducted an experiment to test a theoretical explanation of social facilitation based on the biopsychosocial model of challenge and threat. Participants mastered 1 of 2 tasks and subsequently performed either the mastered (i.e., well-learned) or the unlearned task either alone or with an audience while cardiovascular responses were recorded. Cardiovascular responses of participants performing a well-learned task in the presence of others fit the challenge pattern (i.e., increased cardiac response and decreased vascular resistance), whereas cardiovascular responses of participants performing an unlearned task in the presence of others fit the threat pattern (i.e., increased cardiac response and increased vascular resistance), confirming the authors' hypotheses and the applicability of the biopsychosocial model of challenge and threat to explain these results.

Perceiver threat in social interactions with stigmatized others.

The extent to which stigmatized interaction partners engender perceivers' threat reactions (i.e., stigma-threat hypothesis) was examined. Experiments 1 and 2 included the manipulation of stigma using facial birthmarks. Experiment 3 included manipulations of race and socioeconomic status. Threat responses were measured physiologically, behaviorally, and subjectively. Perceivers interacting with stigmatized partners exhibited cardiovascular reactivity consistent with threat and poorer performance compared with participants interacting with nonstigmatized partners, who exhibited challenge reactivity. In Experiment 3, intergroup contact moderated physiological reactivity such that participants who reported more contact with Black persons exhibited less physiological threat when interacting with them. These results support the stigma-threat hypothesis and suggest the utility of a biopsychosocial approach to the study of stigma and related constructs.