Predicting muscularity-related behavior, emotions, and cognitions in men: The role of psychological need thwarting, drive for muscularity, and mesomorphic internalization.

Background: The muscular ideal physique represents a standard many men internalize as being associated with social, physical, and psychological benefits. Both internalization and the drive for muscularity (DFM) predict appearance-related behaviors, cognitions, and emotions, including muscle dissatisfaction, and excessive weightlifting. These relationships are moderate in strength, however. Examining men’s basic psychological needs may help improve the prediction of appearance-related behaviors, cognitions, and emotions in men. We examine the relationships internalization, need thwarting (NT) and drive for muscularity (DFM), along with their interactions, had with weightlifting, muscle dissatisfaction (MD), and muscle-related-worry (MRW). Methods: 552 men (MAGE = 20.5 years, SD = 3.1) completed the Psychological Need Thwarting Scale, the Internalization Subscale of the male version of the Sociocultural Attitudes towards Appearance Scale, the Drive for Muscularity Scale Attitudes Subscale, the Male Body Attitudes Scale-Muscularity Subscale, the Body Change Inventory Worry Subscale, and an inventory assessing weightlifting behavior. Findings: DFM significantly predicted weightlifting, MRW, and MD. Internalization significantly predicted weightlifting and MRW. NT significantly predicted weightlifting and MD, and its relationship with MRW approached significance (p = .05). The interaction terms did not predict weightlifting or MRW. The NT/DFM and NT/Internalization interaction terms predicted MD. Discussion: These results highlight the role of NT in predicting appearance variables in men and has applied value. Assistance or prevention strategies based on simple relationships between internalization, DFM, and outcomes may not be effective when muscularity-focused issues may be tied to basic human needs.