In this study we explore the link between the social experience of people with intellectual disabilities and core cognitive process that have previously been shown to be related to a range of psychological disorders. Thirty-nine people with intellectual disabilities completed self-report scales measuring the perception of stigma, core negative evaluations and social comparison. Correlation analysis suggests that core negative evaluative beliefs about the self are positively associated with the experience of feeling different: a process that could be described as internalizing the experienced stigma. Relationships were also found between negative self-evaluations and the social attractiveness dimension of the social comparison scale. Using regression techniques stigma was found to have an impact on social comparison processes that was mediated by evaluative beliefs. These findings support a social-cognitive view of the importance of the social world to people with an intellectual disability, and the psychological damage that stigmatization can cause. We discuss interventions that integrate both social and cognitive domains.