Why Is Impaired Social-Acting Understanding Associated with Autism? Evidence for a Unique Role of Ingroup-Support Motivation

Background: Individuals with more autistic traits are less able to understand social acting, the well-intentioned social pretense adults routinely produce to maintain positive relationships with their ingroup (e.g., friends, coworkers, relatives). Social acting can take the form of white lies, false cheer, prevarication, tactful omissions, and so on. Questions have been raised about the mechanisms underlying the impairment in social-acting understanding in autism. One possibility is suggested by recent research on the moral principle of ingroup-love and its corollaries, ingroup-support and ingroup-loyalty. If social acting is intended to support one’s ingroup by maintaining positive interactions, then individuals with poorer ingroup-support motivation (ISM) might be less likely to view social acting as appropriate. If individuals with more autistic traits have weaker ISM, it might explain their difficulties with social-acting understanding.

Objectives: We aimed at testing the hypothesis that ISM mediates the link between autistic traits and social-acting understanding, while comparing and contrasting the role of ISM with seven other theoretically plausible mediators: social desirability, need to belong, and five distinct moral foundations (care/harm, fairness/cheating, loyalty/betrayal, authority/subversion, and sanctity/degradation).

Methods: Study 1 included 133 adults recruited through Amazon Mechanical Turk (60 women and 73 men, mean age = 31.96), who received the following measures: (a) social-acting understanding (Yang & Baillargeon, 2013); (b) Autism Spectrum Quotient (Baron-Cohen et al., 2001); (c) social desirability (Crowne & Marlowe, 1960); (d) need to belong (Leary et al., 2013); (e) moral foundation questionnaire (Graham et al., 2011); and (f) a new ISM measure developed for this study, which assesses how important it is to support (e.g., to help, comfort, or cooperate with) one’s ingroup. Study 2 included 266 adults again recruited through MTurk (150 women and 116 men, mean age = 34.94), who received (a) the social-acting understanding measure from Study 1; (b) Broad Autism Phenotype Questionnaire (Hurley et al., 2007); and (c) one of two versions of ISM (with ratings from the first- or third-person perspective).

Results: Study 1 showed that autistic traits were correlated with weaker social-acting understanding (replicating previous results) as well as with lower ISM, weaker social desirability, and lower reliance on care/harm morality. Among these last three factors, only ISM and the compassion/empathy aspects of care/harm morality significantly mediated between autistic traits and social-acting understanding; when gender was controlled for, only ISM was a significant mediator. Using a larger sample and different measures of autistic traits and ISM, Study 2 replicated and generalized the mediating effect of ISM.

Conclusions: The current results indicate that weak ingroup-support motivation is a key mechanistic explanation for the autistic impairment in social-acting understanding. Individuals with more autistic traits show a weaker motivation to actively support ingroup members, including the motivation to maintain positive interactions, which in turn explains their difficulties in appreciating social acting. The findings substantially extend the literature on social-motivation deficits in autism and raise an important issue in ASD that has received little attention to date.