The Buffer Effect of Social Identity on Psychological Stress in Different Competition Conditions.

Psychological stress arises when perceived situational demands exceed an individual's available coping resources. Beyond individual differences and broader contextual factors, an individual's emotional connection to a group (i.e., social identity) may shape stress appraisals and physiological reactivity. Across two laboratory experiments with 180 college students, we examined whether making social identity salient influences acute stress responses under different competitive frames, comparing intragroup versus intergroup competition. In Experiment 1, participants in the social-identity condition showed numerically lower cardiovascular reactivity than those in the personal-identity condition, but between-condition differences were not statistically significant. In Experiment 2, the Identity × Competition interaction was statistically significant for heart-rate (HR) reactivity, indicating that the effect of identity salience differed across competition frames; however, this interaction did not generalize to systolic/diastolic blood pressure (SBP/DBP) or subjective stress. We also observed higher HR reactivity in intragroup than intergroup competition in this protocol, which we interpret cautiously given the limited consistency across outcomes. Overall, the findings suggest that any identity-related modulation of acute stress responding may be context-dependent and modality-specific, underscoring the importance of competitive framing when evaluating the stress-related consequences of social identity.