Factor index score patterns in the WAIS-III standardization sample

Representative profile subtypes, based on factor index scores, were examined in the standardization sample of the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III). Two-stage cluster analysis identified five reliable subtypes. Three clusters were differentiated primarily by level of performance across all factor index scores (ranging from below average, to average, to above average). The other two clusters were characterized by distinct patterns of performance, with relative efficacy on the Processing Speed index being the most prominent distinction (ranging from a relative weakness to a relative strength). The clusters did not differ significantly in age, but ethnicity and income covaried directly with level of WAIS-III performance, whereas gender affected differential patterns of performance. Furthermore, education and memory were associated primarily with level and, to a relatively minor degree, pattern of WAIS-III performance. Implications for clinical practice are discussed.