The effect of belief in free will on body-related outcomes: The mediating role of internalized weight stigma

This study examines the mediating role of internalized weight stigma in the relationship between belief in free will (BiFW) and psychological well-being, including negative affectivity, state self-esteem, body image dissatisfaction, body appreciation and dieting self-efficacy. Although previous research suggested links between belief in free will and stigmatizing other people's behaviors, to our knowledge, no study has examined the link with stigmatizing oneself—that is, internalized stigma. As a concept, free will is defined as the ability to make free choices, leading to responsibility attributions and those who strongly believe that free will exists could blame individuals while trying to explain the reason for the occurrence of a phenomenon (blaming attribution hypothesis). Moreover, prior research also demonstrated that free will beliefs show positive effects on individuals, since autonomy and sense of control contribute to psychological wellbeing (empowerment hypothesis). The present study included 210 female participants aged 18 and above. Participants were randomly assigned to one of the two conditions: "high belief in free will" and "low belief in free will." Participants in each condition were exposed to task-specific manipulation. Following the free will manipulation, participants completed several questionnaires related to study variables. Current study findings supported the empowerment hypothesis: higher belief in free will decreased internalized weight stigma (IWS) and increased state self-esteem, independently of BMI. The indirect and empowering effects of belief in free will on all outcome variables were supported through the significant mediating role of IWS. It was concluded that believing in free will enhances psychological wellbeing and may act as a buffer against experiencing internalized weight stigma. Moreover, these empowering effects were pervasive regardless of body weight (BMI). Thus, it is suggested that using language that emphasizes the importance of believing in free choice may serve as a protective and enhancing tool against internalized weight stigma and body weight-related psychological outcomes in clinical settings. Key Words: belief in free will, internalized weight stigma, negative affectivity, state self-esteem, body image dissatisfaction, body appreciation, dieting self-efficacy