Associations between self-reported social touch avoidance, hypersensitivity, and autistic traits: Results from questionnaire research among typically developing adults

People with autism spectrum disorder show an avoidance and aversion to interpersonal, social touch. Although this may be caused by symptoms of hypersensitivity, there is little direct evidence to support this claim. Our study addressed this issue by examining the relationship between participants' level of autistic traits, hypersensitivity, and attitudes toward social touch, using online questionnaires. We applied an analog design to study symptoms of autism spectrum disorder in a typically developing sample based on the dimensional model. In our study, we recruited 600 typically developed Japanese adults (aged from 20s to 40s) and collected data using the Social Touch Questionnaire, Autism Spectrum Quotient, and Glasgow Sensory Questionnaire online. The results showed that levels of aversion to social touch positively and significantly correlated with autistic traits and levels of hypersensitivity, while they negatively correlated with levels of hyposensitivity. Our study is the first to substantiate the assumptions made in previous studies, indicating that a higher level of hypersensitivity in people with autism spectrum disorder may cause tactile defensiveness and avoidance of social touch. This implies that problems in sensory information processing may be underlying difficulties in social interaction among people with autism spectrum disorder.