Measuring weight- and shape-based social identity threat vulnerability in young adults

This study assessed the factor structure of a novel self-report measure of weight- and shape-based social identity threat vulnerability, Social Identities and Attitudes Scale-Weight and Body Shape (SIAS-WBS). Weight and race diverse young adults (N = 542; M_age=21.69 +2.32; 69% ciswomen) were recruited from Amazon Mechanical Turk and a university participant pool. Exploratory and confirmatory factor analyses, measurement invariance, internal consistency, convergent validity, and test-retest reliability were conducted. The SIAS-WBS had acceptable factor structure with 15 subscales that were invariant across race, ethnicity, gender, weight perception, and CDC-defined weight groups. The measure demonstrated high internal consistency, convergent validity, and good test-retest reliability. Subscales were Weight & Shape Identification (Influence and Centrality), Weight & Shape Stigma Consciousness, six identification and six negative affect factors across the domains of: Social, Familial, Romantic, Intellectual, Physical Activity, and Physical Attractiveness. Participants in higher weight groups who perceived themselves as lower weight status, reported lower Weight & Shape Identification-Influence (p = 0.02) and lower Stigma Consciousness (p = 0.01), relative to those perceiving themselves as higher weight status. Participants perceiving themselves as higher weight status endorsed lower Physical Activity Identification (p < 0.001) and more negative affect across all domains (p's < 0.02). This suggests that weight misperceivers may be less susceptible to weight-based identity threat.