Construct Validity of the WAIS- 5: Complementary Exploratory and Confirmatory Factor Analyses of the 20 Primary and Secondary Subtests

The Wechsler Adult Intelligence Scale-Fifth Edition (WAIS-5) latent factor structure was assessed using complementary hierarchical exploratory factor analyses (EFA) with the Schmid and Leiman procedure and confirmatory factor analyses (CFA) using the standardization sample (<i>N</i> = 2,020) correlation matrix and descriptive statistics of the 20 primary and secondary WAIS-5 subtests. The WAIS-5 Technical and Interpretive Manual did not include EFA, CFA with fewer than five first-order (group) factors, CFA with rival bifactor models, or model-based reliability and dimensionality estimates; thus, the present independent structural validity assessment corrects this evidential lacuna to help guide ethical and evidence-based interpretation. EFA results did not support five latent factors with separate Visual Spatial and Fluid Reasoning factors. Instead, a four-factor model with Visual Spatial and Fluid Reasoning factors merged into the former Perceptual Reasoning factor and measurement dominated by a general intelligence (<i>g</i>) factor-similar to the WAIS-IV structure-was supported. CFA results indicated that a bifactor model with four group factors provided the best fit, consistent with the EFA findings. Overall, the EFA and CFA results did not support the purported WAIS-5 structure and instead replicated findings from independent assessments of the WISC-V with standardization and clinical samples, that indicated primary, if not exclusive, interpretation of the FSIQ as an estimate of psychometric <i>g</i>.