Criterion-Related Validity of the Theory of Mind Inventory-2 Self-Report Form for Adults with Autism Spectrum Disorder

Background:

From identifying areas of strengths and challenges to assessing intervention efficacy, detailed social functioning measures are needed to best support individuals with ASD across the lifespan. Self-report tools in particular empower individuals to share their experiences in a meaningful way. The Theory of Mind Inventory-2, originally developed as a caregiver-report measure of theory of mind, has been adapted to a self-report format. Limited theory of mind is characteristic of ASD which has implications for a range of social skills, including gaze perception. To understand the utility of this measure, we compare the ToMI-2-SR to other self-reports of social skills as well as to eye tracking outcomes in a population of young adults.

Objectives:

1) To examine how the self-report form of the ToMI-2 is comparable to other social skills measures and eye tracking outcomes

2) To examine whether the ToMI-2-SR adds unique variance above and beyond existing measures of social functioning

Methods:

A total of 36 young adults (M_age(SD)= 20.5 (2.2), Average brief IQ = 113.0 (13.5), 41.7% female, 42% with a diagnosis of ASD or PDD) completed an eye tracking task and self-report questionnaires: Theory of Mind Inventory-2- Self Report (ToMI-2-SR), Social Responsiveness Scale (SRS), and Adult Self-Report (ASR). Four eye tracking conditions mimicking different gaze detection scenarios (averted gaze, mutual looking, getting caught staring, and catching another staring) were presented and four eye tracking outcomes are examined. Between group effects and bivariate correlations were conducted to explore theoretically-based tests of construct validity. More specifically, Pearson correlations were calculated between the ToMI-2-SR Advanced subscale, the SRS (Social Cognition and Social Communication subscales), ASR (Withdrawn and Thought Problems scales), and eye tracking outcomes (interest area (IA) dwell time, trial dwell time, IA first and second fixation duration).

Results:

A significant group difference emerged between the ASD/PDD group and the typically-developing group (t(34) = 4.53, p<.001 on what?. The ToMI-2_SR Advanced subscale was significantly correlated with the Social Cognition (r=-.67, p<.001) and Social Communication (r=-.72, p<.001) subscales of the SRS, as well as the Withdrawn (r=-.50, p<.005) and Thought Problems (r=-.52, p<.005) scales of the ASR. IA and trial dwell time were significantly correlated with ToMI-2-SR across all conditions except ‘averted.’ First fixation duration was significant in the averted condition (r=-.44, p<.01). Second fixation duration was significant in the ‘getting caught staring’ condition (r=.36, p<.05).

Conclusions:

Correlations between the ToMI-2-SR and other ASD-related scales were significant (and consistent with previous results using the caregiver version of the ToMI), providing evidence of criterion-related validity of the self-report form. Of particular interest is that correlations between eye tracking outcomes and the ToMI-2-SR followed a different pattern of correlations than between eye tracking outcomes and other measures of social skills. The unique contribution of the ToMI-2-SR has important implications for understanding gaze detection and social functioning. As adults with ASD continue to advocate for themselves (nothing about us without us!), well-established self-report measures will serve an increasingly key role in including individuals with ASD in their own care.