Perceived dissimilarity in autistic and non-autistic youth

Adolescence is a pivotal time for peer relationships. However, there is a historic rise in adolescent loneliness, and autistic youth may be at particular risk. Evidence suggests feelings of similarity drive friendship formation and continuation. Youth who feel dissimilar to peers may have fewer opportunities to develop friendships. In the current study, we developed a Perceived Dissimilarity Scale to assess autistic and non-autistic youth perceptions of dissimilarity to other kids in general and to a friend. We then examined if youth perceptions of dissimilarity associated with related constructs and concurrent and future loneliness. 194 adolescents (36% autistic, 36% female, 64% White, Mage = 12.81) participated in the study. At the first assessment, youth self-reported perceived dissimilarity, perceived disconnection and loneliness and completed an fMRI scan to assess neural similarity. At the second and third assessments, youth self-reported loneliness. Exploratory factor analysis indicated we developed a Perceived Dissimilarity Scale with two discrete subscales (kids vs friend) that had high internal consistency across groups (α’s ≥ .80). Autistic youth experienced more perceived dissimilarity, perceived disconnection and loneliness than their non-autistic peers, particularly to kids rather than to a friend. Autistic youth with greater neural similarity reported more perceived dissimilarity to kids, whereas non-autistic youth with lesser neural similarity reported more perceived dissimilarity to kids. Additionally, perceived dissimilarity to kids mediated the relation between group and loneliness. Our Perceived Dissimilarity Scale is a valuable metric for understanding individual differences in youth and may better explain experiences of loneliness than an autism diagnosis alone.