An empirical evaluation of the reliability and validity of the "reading the mind in the eyes" test
The Reading the Mind in the Eyes test (RMET) is a widely used measure of theory of mind (ToM) ability that was originally designed to detect ToM deficits in autistic adults and validated based on the performance of autistic individuals. Despite its popularity, there are questions regarding the test’s factor structure, whether it taps mental state reasoning components of ToM or simply emotion recognition ability, and its validity for use in non-autistic populations. In the current study, a US representative sample of 1,181 adults completed the RMET, the Toronto Alexithymia Scale, and the Autism Spectrum Quotient. Exploratory factor analysis (EFA) on the full sample and separate EFA on individuals with high and low levels of autistic traits provided evidence for a three-factor model and two overlapping, but distinct, three-factor models for individuals with high versus low levels of autistic traits. However, the RMET had poor psychometric properties for all three groups. Hierarchical regression analysis and structural equation modelling suggested that levels of alexithymia traits and autistic traits each predict performance on the RMET. I conclude that the lack of strong psychometric properties for the RMET, evidence of variation in performance across samples, and the absence of theoretical explanations for how the test captures ToM ability undermine the validity of the RMET. I argue that until these issues are satisfactorily addressed, researchers should not use the RMET as a measure of social cognition.