Running title: Self-discrimination IAT

1 Stigmatized obese individuals tend to internalize the pervasive weight stigma which 2 might lead to self-discrimination and increased psychopathology. While explicit and 3 implicit weight stigma can be measured using self-report questionnaires and Implicit 4 Association Tests (IAT), respectively, the assessment of self-discrimination relied 5 solely on self-report. The present study sought to develop an IAT measuring implicit 6 self-discrimination (SD-IAT) in samples of obese individuals with and without binge7 eating disorder (BED). Seventy-eight individuals were recruited from the community 8 and individually matched in three groups. Obese participants with BED, obese 9 participants without BED (OB), and a normal weight control group without eating 10 disorder psychopathology (HC) were assessed with the SD-IAT and other measures 11 relevant for convergent and discriminant validation. Results revealed significantly 12 higher implicit self-discrimination in the BED group when compared to both OB and 13 HC. Furthermore, significant correlations were found between the SD-IAT with body 14 mass index, experiences of weight stigma, depressive symptoms, and implicit self15 esteem. Finally, implicit self-discrimination predicted eating disorder 16 psychopathology over and above group membership, and experiences of weight 17 stigma. This study provides first evidence of the validity of the SD-IAT. Assessing 18 implicit self-discrimination might further increase understanding of weight stigma and 19 its significance for psychosocial functioning among vulnerable obese individuals. 20