Psychometric analysis of the Empathy Quotient (EQ)

This study assessed the dimensionality of the Empathy Quotient (EQ) using two statistical approaches: Rasch and Confirmatory Factor Analysis (CFA). Participants included N = 658 with an autism spectrum condition diagnosis (ASC), N = 1375 family members of this group, and N = 3344 typical controls. Data were applied to the Rasch model (Rating Scale) using WINSTEPS. The Rasch model explained 83% of the variance. Reliability estimates were greater than .90. Analysis of differential item functioning (DIF) demonstrated item invariance between the sexes. Principal Components Analysis (PCA) of the residual factor showed separation into Agree and Disagree response subgroups. CFA suggested that 26-item model with response factors had the best fit statistics (RMSEA.05, CFI .93). A shorter 15-item three-factor model had an omega (ω) of .779, suggesting a hierarchical factor of empathy underlies these sub-factors. The EQ is an appropriate measure of the construct of empathy and can be measured along a single dimension.