Social Motivation in Adults with Autism: A Multi-method Approach

Social difficulties are suggested to be at the core of Autism Spectrum Disorders (ASD), and they persist into adulthood regardless of cognitive functioning and language abilities. The Social Motivation Theory (Chevalier et al., 2012) is proposed to explain social difficulties in ASD. The current thesis aimed to investigate social behaviour in relation to social motivation in adults with and without ASD. To this end, Study 1 and 2 utilized experimental paradigms to understand behavioural and psychophysiological correlates of social exclusion and social judgements in ASD and neurotypical (NT) adults. Using the Cyberball paradigm in Study 1, the experience of social exclusion was similar in the NT and ASD group, and physiological responses to exclusion did not reveal clear group differences. Using the Social Judgement Task in Study 2, it was found that while NT participants showed a clear cardiac slowing to unexpected social rejection, the autistic group showed this slowing in response to negative feedback more generally. Moreover, in both experimental studies, there was significant variability of psychophysiological responses both within and between groups. For all participants, high social anxiety was associated with heightened feelings of exclusion (Study 1) and higher expectations of rejection (Study 2). The second part of the thesis focused on autistic testimony to understand social experiences of autistic and neurotypical adults. Study 3 demonstrated that autistic university students reported social challenges as well as academic strengths at university. Study 4 emphasized substantial individual differences in social motivation using self-report questionnaires. Older age and higher autistic traits predicted lower social motivation in both autistic and neurotypical adults, however, alexithymia played an additional role in social motivation in the ASD group only. Moreover, subgroups within ASD were defined using cluster analysis based on social motivation, social skills, and social anxiety. Finally, friendship experiences were investigated by combining questionnaire data with qualitative insights (Study 5). Results showed that many autistic adults reported a desire to make friends despite challenges in social communication. Overall, this mixed-methods thesis emphasized that there are not clear social motivation deficits in autistic adults and there is significant variability in social motivation within ASD, which might be associated with factors such as social skills and social anxiety