Evaluating validity and test-retest reliability in four drive for muscularity questionnaires

The current study assessed relationships among four commonly used drive for muscularity questionnaires, along with their 7 and 14 day test-retest reliability. Sample 1 was comprised of young British adult males (N=272; M(AGE)=20.3) who completed the questionnaires once. Sample 2, a group of young British adult males (N=54, M(AGE)=19.3), completed the questionnaires three times spaced 7 and 14 days apart. Correlations among Sample 1 ranged from .20 to .82 providing evidence for concurrent and discriminant validities. Evidence for test-retest reliability emerged with intraclass correlations ranging from .78 to .95 (p<.001) and generally nonsignificant t-tests (p>.05). Overall, the data support the psychometric properties of the drive for muscularity inventories; however, the shared variance (35-67%) hints that refinement is possible.