title: The psychometric properties of the "Reading the Mind in the Eyes" Test: an item response theory (IRT) analysis.
abstract: BACKGROUND
  The "Reading the Mind in the Eyes" Test (hereafter: Eyes Test) is considered an advanced task of the Theory of Mind aimed at assessing the performance of the participant in perspective-takingthat is, the ability to sense or understand other people's cognitive and emotional states. In this study, the item response theory analysis was applied to the adult version of the Eyes Test.
  
  
  METHODS
  The Italian version of the Eyes Test was administered to 200 undergraduate students of both genders (males = 46%). Modified parallel analysis (MPA) was used to test unidimensionality. Marginal maximum likelihood estimation was used to fit the 1-, 2-, and 3-parameter logistic (PL) model to the data. Differential Item Functioning (DIF) due to gender was explored with five independent methods.
  
  
  RESULTS
  MPA provided evidence in favour of unidimensionality. The Rasch model (1-PL) was superior to the other two models in explaining participants' responses to the Eyes Test. There was no robust evidence of gender-related DIF in the Eyes Test, although some differences may exist for some items as a reflection of real differences by group.
  
  
  CONCLUSIONS
  The study results support a one-factor model of the Eyes Test. Performance on the Eyes Test is defined by the participant's ability in perspective-taking. Researchers should cease using arbitrarily selected subscores in assessing the performance of participants to the Eyes Test. Lack of gender-related DIF favours the use of the Eyes Test in the investigation of gender differences concerning empathy and social cognition.
authors.affiliation: a Psychiatry Branch , Centro Medico Genneruxi , Cagliari , Italy.|b Section of Clinical Psychology, Department of Education, Psychology, and Philosophy , University of Cagliari , Cagliari , Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Preti
authors.affiliation: b Section of Clinical Psychology, Department of Education, Psychology, and Philosophy , University of Cagliari , Cagliari , Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Vellante
authors.affiliation: b Section of Clinical Psychology, Department of Education, Psychology, and Philosophy , University of Cagliari , Cagliari , Italy.
authors.forename: Donatella R
authors.initials: DR
authors.lastname: Petretto
mesh_terms: D000328:Adult; D000342:Affective Symptoms / Q000523:psychology*; D003627:Data Interpretation, Statistical; D004645:Empathy; D005123:Eye; D005260:Female; D005783:Gender Identity; D006801:Humans; D008297:Male; D008960:Models, Psychological; D009483:Neuropsychological Tests; D011594:Psychometrics / Q000592:standards*; D015203:Reproducibility of Results; D055815:Young Adult
keywords: Reading the mind in the eyes; differential item functioning; item response theory; social cognition; theory of mind