CHC model according to weiss evidence from the WAIS-IV administration to Italian adults and elders

The Italian version of the Wechsler Adult Intelligence Scale – Fourth Edition (WAIS-IV) – was standardized using a sample of 2,174 participants, aged between 16 and 90 years. The WAIS-IV consists of 10 core subtests and 5 supplemental subtests. While the 70–90 yr group is usually excluded from three of the five supplemental subtests (Letter-Number Sequencing, Figure Weights, and Cancellation), we administered all 15 subtests both to adults and elderly people. The aim of the present study was to investigate the factorial invariance of the Weiss and colleagues’ hierarchical five-factor CHC (Cattell-Horn-Carroll) model in Italian adults and elders. The overall results of this study generally support both the configural and factorial invariance of the WAIS-IV, and hence the five-factor CHC model of Weiss is equivalent in adults and elderly people. However, for the elderly sample we found higher loadings of WAIS-IV subtests on the second-order g factor.