Background Autism spectrum disorder (ASD) is a neurodevelopmental disorder defined by social communication deficits, repetitive behaviors and restricted interests. Studies have reported aberrant sensory responses, including altered experiences of social touch, in individuals with ASD. However, the relationship between atypical social touch and social networks in ASD remains poorly understood. Social touch is used to strengthen and manage social networks in many species. Studies in general populations across diverse cultures show that the extent of permissible touch is consistently linked to the strength of emotional bonds between the toucher and the touched individual. This study examined relationship-specific patterns of social touch and their association with emotional bonding in individuals with ASD.

Methods Seventy adults with ASD and 70 typically developed (TD) adults rated their emotional bonds with different social network members (e.g., partners, fathers, strangers) and the pleasantness of being touched by each. Participants also identified body regions where they allowed touch. We hypothesized that patterns of interpersonal touch allowance and emotional bonding, and their relationship, would differ between ASD and TD adults.

Result In all social network members except children and female friends, ASD adults allowed significantly less social touching than TD adults. Compared to TD adults, ASD adults also reported having significantly weaker emotional bonds with one social network member and experiencing significantly less pleasantness when touched by multiple members of their social network. In both groups, strength of emotional bond was significantly correlated with permissible touch area. Linear regression analyses showed that our ASD participants were more reliant on bodily touch allowance for emotional bonding than the TD controls.

Limitations More participants are necessary to secure sufficient number of social network members in ASD.

Conclusions Our results suggest that adults with ASD generally prefer less social touch from most social network members and show reduced emotional bonding with only a specific connection. In addition, touch allowance was more strongly associated with emotional bonding in ASD than TD adults. These findings highlight the influence of autistic traits on the relationship between social touch and emotional bonding within social networks.