This study investigated whether hyper-responsiveness to touch serves as a mediating variable that predicts social dysfunction in adults with autism spectrum disorders (ASD). Data were obtained from all adults with administratively defined intellectual disability in a region in Sweden (n = 915, where 143 had ASD). A multiple mediation modeling analysis revealed a well-fitted model (Satorra-Bentler scaled chi-square = 10.91, df = 7, p = 0.14, CFI = 0.99, RMSEA = 0.025), demonstrating that social dysfunction among adults with ASD was completely mediated by hyper-responsiveness to touch followed by impairment of speech and aggressive/destructive behavior. The results demonstrated that in adulthood, the tactile sensory system is foundational for social functioning in people with ASD, with diagnosis and intervention implications.