Psychometric Evaluation of the Emotion Regulation Questionnaire (ERQ) in Peruvian Psychology Undergraduates: Factor Structure, Reliability, and Measurement Invariance Across Sex

Evidence for the original adult Emotion Regulation Questionnaire (ERQ) in Peruvian university populations remains limited, particularly regarding score comparability across sex. This cross-sectional psychometric study evaluated the factor structure, internal consistency, and sex-related measurement invariance of the original 10-item ERQ and an exploratory nine-item configuration in 414 psychology undergraduates from a private university in Trujillo, Peru. The correlated two-factor ERQ-10 showed a mixed but viable fit (χ2(34) = 84.56, CFI = 0.933, RMSEA = 0.060, 90% CI [0.044, 0.076], SRMR = 0.057), with positive loadings ranging from 0.381 to 0.806. Post hoc exclusion of Item 1 produced a stronger approximate fit (χ2(26) = 46.03, CFI = 0.971, RMSEA = 0.043, 90% CI [0.021, 0.063], SRMR = 0.045), but reliability changed negligibly. For the nine-item configuration, full metric invariance was not supported; partial metric, partial scalar, and partial strict invariance were supported after freeing the Item 5 loading across sex. The ERQ-10 therefore remains viable for group-level research in this sample, whereas the alternative configuration should be regarded as a sample-derived hypothesis requiring independent replication, broader samples, and evidence based on external variables.