Social identity processes affect objectively measured physical health: A systematic review and meta-analyses

A systematic review (CRD42023422237) examined the effect of social identity processes on objectively measured physical health.

Eligible studies (a) quantitatively manipulated or measured social identity strength, salience, or threat, or multiple group membership, and (b) objectively measured (i.e., nonself-report) health behavior, physical health, or health-relevant biomarker. PsychINFO, PubMed, and SPORTDiscus were searched (24 September 2024). We conducted narrative synthesis, meta-analysis for sufficiently homogenous subclusters, and risk of bias assessment.

The 106 studies (N_total = 290,816; 20 countries; published 1982-2024) were highly diverse in design and dependent variables and were grouped into five discrete clusters. First, 46 studies assessed whether threats to social identities increased acute cardiovascular reactivity, g = 0.40, 95% confidence interval (CI) = [.179, .617] (42 effects, N = 1,432). Second, 21 studies assessed whether social identity salience reduced stress biomarkers, g = -0.28, 95% CI = [-.544, -.006] (20 effects, N = 487). Third, 16 studies (too heterogenous for meta-analysis) found evidence of ingroup normative influence on health behaviors. Fourth, six studies (too heterogenous for meta-analysis) assessed social identification in health interventions; five found benefits for disease-related outcomes. Finally, 17 studies examined the protective effect of subjective (multiple) group membership on long-term health (e.g., mortality), OR = .59, 95% CI = [.385, .891] (eight effects, N = 27,985). Studies were high quality on average, although there was some evidence of publication bias.

Results provide evidence for both social cure and social curse predictions of the social identity approach to health. We identified five distinct ways in which social identity processes affect physical health. (PsycInfo Database Record (c) 2026 APA, all rights reserved).