Exploring Pragmatic Abilities in Sisters of Autistic Individuals: A Methodological Solution to Female Autism Research

Autism is more frequently diagnosed in males than females. One possible explanation for this discrepancy is that autistic females may be overlooked because they show different, subtler signs of autism. For example, sex differences have been reported in pragmatic abilities. However, studying these sex differences is challenging, because diagnosed autistic females may not represent all autistic females-many remaining undiagnosed. To address this issue, our study included adolescent females at increased likelihood for autism: sisters of autistic individuals. Adolescence is a key period when autism-related difficulties often become more visible. We compared the pragmatic abilities of 76 female participants aged between 9 and 16 years old across three groups: autistic, nonautistic, and sisters of diagnosed autistic individuals. Participants completed a semistructured, spoken narrative task, which was analyzed for coherence and fluency. Their caregivers completed several questionnaires to assess both pragmatic abilities and global difficulties. At the group level, caregiver reports indicated an in-between position for sisters: they experienced more pragmatic-related difficulties than nonautistic participants but fewer than autistic participants. Narratives revealed no differences between sisters and nonautistic participants, with one exception: they gave fewer causal explanations of characters' mental states. Individual profiles of sisters revealed a heterogeneous group, varying from no difficulties at all to pragmatic profiles closely resembling those of autistic females.