The Serial Relation of Theory of Mind and Functional Communication in the Externalizing Problems of Children with ASD

Background: Previous research indicates children with autism spectrum disorder (ASD) exhibit greater externalizing problems than typically developing (TD) peers (Mahan & Matson, 2011). One factor that has been found to contribute to these greater externalizing problems is lower functional communication (FC) skills (Boonen et al., 2014). While lower FC skills may play a role in the increased externalizing problems observed in children with ASD, it alone accounts for only part of variance in this relation. Other factors related to FC, such as theory of mind (ToM), may also play a role in this well-established association. Understanding the relation among these factors is essential in determining appropriate treatment for children with ASD who have comorbid externalizing problems.

Objectives: Our objective was to develop a greater understanding of factors that may contribute to externalizing problems in children with ASD. We hypothesized that ToM abilities and FC skills would serially mediate the relation between children’s status and externalizing problems.

Methods: Our sample included 111 children (ages 3:0 to 6:11) and their parents. Sixty-five TD children (40% female) and 46 children with ASD (21% female) were examined. Children completed a ToM battery in a laboratory setting. Parents’ ratings from the BASC-2 (Reynolds & Kamphaus, 2004) were used to evaluate children’s externalizing problems and FC. The DAS-II(Elliott, 2007) was used to assess children’s language abilities.

Results: A serial mediation model was conducted using the SPSS 24 macro PROCESS (Hayes, 2008), which provided bootstrapped estimates of the indirect effects based on 5000 resamples. Age, language abilities, and gender were controlled for in the analysis.

Results indicated status was negatively associated with ToM abilities (B = -.91, p < .05) and parent-reported FC skills (B = -7.21, p < .001). The direct effect of status on externalizing problems was also significant (B = 9.55, p < .001). Results supported the mediating role of the child’s FC skills (B = 2.29, CI₉₅ = .70 to 5.02) in the relation between status and externalizing problems. However, the mediating role of the child’s ToM abilities was not significant (B = -.22, CI₉₅ = -1.67 to .67) in the association between status and externalizing problems. The results supported a serial mediation, such that when compared to TD children, children with ASD had lower ToM abilities, which predicted lower FC skills, which was associated with greater externalizing problems (B = .25, CI₉₅= .02 to .98). This model accounted for 32% of the variance in predicting externalizing problems in our sample.

Conclusions: These results supported our hypothesis that the association between status and externalizing problems was serially mediated by ToM and FC skills. These results indicate that, compared to TD children, children with ASD may have difficulty understanding others’ perspectives, as evidenced by lower ToM abilities, and this may impact their ability to communicate effectively. Lower FC skills may increase frustration and subsequently lead to greater externalizing problems. These findings suggest interventions that incorporate ToM training may not only increase FC skills, but also lead to decreased externalizing problems in children with ASD.