Physical appearance as a measure of social ranking: the role of a new scale to understand the relationship between weight and dieting.

This study presents the development of a new self-report instrument to assess how an individual perceives himself as social agent within his group having physical appearance as a reference, the Social Comparison through Physical Appearance Scale (SCPAS). This scale adds to the existent measures by assessing the social ranking based on one's physical appearance, and not the tendency to make comparisons of the general physical appearance or specific body parts. Its psychometric characteristics are investigated in a sample of 828 female participants from normal population. Principal components analysis was conducted for each part of the instrument: the Part A: peers shows a 2-factor structure (Attractiveness/Rank and Group Fit) explaining 72.142% of the variance; the Part B: models presents a one-dimensional structure that explains 69.191% of the variance. Findings show very good internal consistency coefficients and test-retest reliability. The two parts of the SCPAS are significantly associated to social comparison and shame measures, to anxiety, depression and stress indicators, and to eating disorders symptomatology. The scale discriminates between a clinical sample of 91 patients with an eating disorder and a non-clinical sample of 102 participants. Regression analyses pointed out that social comparison through physical appearance with peers and models partially mediates the effect of the dissatisfaction with current weight on disordered eating, namely drive for thinness.