An analysis of the Verbal Comprehension Index of the Wechsler Adult Intelligence Scale—Fourth Edition (WAIS–IV) using the Model of Hierarchical Complexity (MHC): Why might stage be a better measure of “smarts” than verbal IQ?

While IQ tests are the most common and largely accepted measurement of how “smart” a person is, whether they are the best measure of this construct is up for debate. This paper will discuss the relationship between IQ tests and their corresponding order of hierarchical complexity developmental stage scores based on the model of hierarchical complexity (MHC). The Verbal Comprehension Index (VCI) scales of the Wechsler Adult Intelligence Scale—Fourth Edition (WAIS–IV) were used for scoring. The study shows that, according to the Hierarchical Complexity Scoring System (HCSS), the WAIS–IV fails to test verbal intelligence beyond the formal stage. This study used Rasch analysis to demonstrate that scoring the VCI of the WAIS–IV from a developmental sequence using the HCSS was successful in explaining the majority of the difficulty in VCI items. Much of the additional difficulty of tasks came from the knowledge of rare items and noise. This demonstrates the ceiling effect of the VCI of the WAIS–IV. Difficulties with scoring items, additional limitations with the IQ test, and their implications are discussed.