Abstract
Fragile X syndrome (FXS) is a well-described inherited cause of intellectual disability and the most common known genetic cause of autism. Social deficits in girls with FXS are not well understood. To better understand barriers to social functioning that may contribute to mental health outcomes, we administered a theoretically based social information processing (SIP) interview about challenging social situations to 11 verbal mental age-matched girls with and without FXS. We hypothesized that (a) girls with FXS have global SIP impairments and (b) less autism symptomatology is related to better SIP skills in girls with FXS. Compared to controls, girls with FXS performed significantly worse on an early SIP skill (problem identification). Scores on later SIP skills tended to be lower and exhibited moderate to strong effect sizes. Competency in goal generation was correlated with autistic-like communication skills. Systematic studies of SIP skills in larger cohorts of girls with FXS are warranted.