Abnormal functioning of primary brain systems that express and modulate basic emotional drives are increasingly considered to underlie mental disorders including autism spectrum disorders. We hypothesized that ASD are characterized by disruptions in the primary systems involved in the motivation for social bonding. Twenty adults with ASD were compared to 20 neurotypical participants on the basis of self-reports and clinical assessments, including the Social Anhedonia Scale (SAS) and the Affective Neuroscience Personality Scales (ANPS). ASD diagnosis was related to SAS, as well as to positive (PLAYFULNESS) and negative (FEAR) ANPS-traits. In the overall sample, levels of autistic traits (AQ) were related to SAS and PLAYFULNESS. We argue that PLAYFULNESS could be at the root of social bonding impairments in ASD.