Classic Social Psychological Phenomena across the Autism Spectrum: Three Empirical Tests of the Integrated Self-Categorization Model of Autism

Background: Skorich and colleagues (2016; 2017) have proposed a model of autism that integrates the theory of mind (ToM) and weak central coherence (WCC) features of the disorder, which they term the Integrated Self-Categorization Model of Autism (ISCA). This model leads to a number of novel hypotheses, in particular predicting that people with autism should be less susceptible to classic social psychological phenomena, such as ingroup favoritism, cooperative social interdependence, and outgroup homogeneity. The current paper reports 3 experiments exploring the degree to which participants show each of these effects as a function of their autistic tendencies.

Objectives: The research reported in the current paper aims to test the ISCA model, by way of 3 empirical studies investigating some of the novel hypotheses of the model. The first experiment explores the degree to which autistic tendencies relate to ingroup favoritism, the second explores the degree to which autistic tendencies relate to social interdependence, and the third explores the degree to which autistic tendencies relate to outgroup homogeneity.

Methods: All three studies were conducted online, with the Autism Quotient (AQ) used as a measure of autistic tendencies in the general population samples recruited. In the first study, participants were asked to complete the minimal group paradigm, in which participants are randomly placed into made-up groups and then asked to allocate resources to ingroup and outgroup members, as a measure of ingroup favoritism. In the second study, participants were asked to complete the prisoners’ dilemma, in which participants are paired with another player and then asked to decide between mutually beneficial and individually beneficial outcomes, as a measure of their tendencies toward cooperative social interdependence. In the final study, participants were asked to rate either their own national (in)group or another national (out)group on a number of traits, as a measure of the degree to which they perceive the outgroup as more or less homogenous than their ingroup.

Results: The first study revealed a negative relationship between AQ and ingroup favoritism, such that high AQ participants showed less ingroup favoritism than low AQ participants. The second study revealed a negative relationship between AQ and cooperative, socially interdependent decisions, such that high AQ participants showed less cooperation and more competition than low AQ participants. The final study revealed that high AQ participants perceived both their ingroup and their outgroup as less homogenous than low AQ participants.

Conclusions: These results suggest that autistic tendencies are associated with decreased susceptibility to classic social psychological phenomena. Taken together, they provide strong evidence for the ISCA model, and for its contention that people with autism have a decreased tendency to self-categorize, which is related to WCC, and which results in the ToM and associated social-communication problems on which diagnosis is based.