An IRT Analysis of the Reading the Mind in the Eyes Test.

The Reading the Mind in the Eyes Test (RMET; Baron-Cohen, Wheelwright, Hill, Raste, & Plumb, 2001 ), originally designed for use in clinical populations, has been used with increasing frequency as a measure of advanced social cognition in nonclinical samples (e.g., Domes, Heinriches, Michel, Berger, & Herpertz, 2007 ; Kidd & Castano, 2013 ; Mar, Oatley, Hirsh, de la Paz, & Peterson, 2006 ). The purpose of this research was to use item response theory to assess the ability of the RMET to detect differences at the high levels of theory of mind to be expected in neurotypical adults. Results indicate that the RMET is an easy test that fails to discriminate between individuals exhibiting high ability. As such, it is unlikely that it could adequately or reliably capture the expected effects of manipulations designed to boost ability in samples of neurotypical populations. Reported effects and noneffects from such manipulations might reflect noise introduced by inaccurate measurement; a more sensitive instrument is needed to verify the effects of manipulations to enhance theory of mind.