Insistence on Sameness, Anxiety, and Social Motivation in Children with Autism Spectrum Disorder

Background:  Restricted repetitive behaviors (RRBs) are a key feature of autism spectrum disorder (ASD; American Psychiatric Association, 2013). While the function of RRBs in ASD is currently unclear, RRBs have been identified as a possible anxiety reduction strategy (Joosten et al., 2009). Anxiety is prevalent in individuals with ASD (White et al., 2009), and anxiety triggers in ASD include social interaction and the disruption or change of routines (Ozsivadijan, Knott, & Magiati, 2012), which clearly intersect with the insistence on sameness (IS) domain of RRBs. RRBs can also affect socialization by decreasing the likelihood of positive peer interactions (Nadig, Lee, Singh, Bosshart, & Ozonoff, 2010) and interference with daily life (South, Ozonoff, & McMahon, 2005). Further, social skills training for children with ASD has been shown to increase social interactions and reduce RRBs (Loftin et al., 2008). 

Objectives:  The present study attempts to link low social motivation and anxiety to RRBs, specifically IS, by examining the mediating role of social motivation between anxiety and RRBs in children with ASD. Examining these relationships may provide guidance on intervention strategies for children with ASD. 

Methods:   Participants were part of an ongoing assessment database of individuals with and without ASD. At the time of analysis, the database had 81 participants. Unaffected controls (n = 25) were not included. After removing participants due to incomplete data, the sample used included 44 participants from 2 to 17 years (M = 6.91, SD = 3.64), were 80% male (n = 35), and race/ethnicities were reported as 84.1% White (n = 37), 6.8% Black (n = 3), 4.5% Asian (n = 2), and 4.5% Other (n = 2). At the assessment appointment, clinical interviews and behavioral assessments were completed and ASD diagnosis was determined by the assessment team and a licensed clinical psychologist, based on DSM-5 criteria.

Results:   The Baron & Kenny (1986) approach was used as a preliminary evaluation of the proposed mediation model. Anxiety was positively associated with the proposed mediator, social motivation deficits (β = 0.49, p < 0.01), as well as the outcome variable, sameness behavior (β = 0.46, p < 0.01), such that higher anxiety was related to increased social motivation deficits and increased sameness behaviors. When both the mediator and the outcome variable were included, the total effect remained significant (adjusted R² = 0.30, F(2,41) = 10.35, p < 0.01). Furthermore, there was a significant direct effect (β = 0.33, p = 0.03), indicating partial mediation. To verify the indirect effect, a bootstrapping simulation using 1000 samples was performed. Results indicated social motivation partially mediated the relationship between anxiety and IS as evidenced by a significant indirect effect (M = 0.13, 95% CI [0.02, 0.27]). 

Conclusions:  These findings suggest a relationship between anxiety, RRBs, and social motivation. In particular, anxiety was positively related to IS, which was partially accounted for by deficits in social motivation. The results shed light on how these ASD features are linked and suggest that intervention for sameness behaviors should address both social motivation and anxiety.