The Wechsler Adult Intelligence Scale (WAIS-III) is widely used in clinical practice but has been subject to criticism due to lack of theoretical foundation. Particularly, the disproportionate assessment of cristallized intelligence (Gc), in comparison to fluid intelligence (Gf) is repeatedly noticed. Gf is in fact a reflection of executive functioning (EF) a set of abilities that includes mental flexibility, planning and problem solving, and (social) decision making. A more balanced assessment of Gc and Gf is important because Gf has significant impact on overall cognitive functioning.

Gaining insight in the degree to which WAIS-III variables are saturated with EF.

Examining the relationship between subtests of the WAIS-III and executive functions in a heterogeneous sample consisting both psychiatric patients and healthy volunteers.

The Behavioural Assessment of the Dysexecutive Syndrome, Wisconsin Card Sorting Test, and Stroop Color-Word Test were administered to a heterogeneous group of 234 psychiatric patients and 24 healthy volunteers. Maximum likelihood procedures with promax rotation were applied to two, three and four factor solutions.

The four factor model fitted the data best, confirming the four factor indices of the WAIS-III. All three executive tasks had their highest loading on the factor corresponding to the perceptual organization index of the WAIS-III.

Present study results confirm the overload of crystallized intelligence in the subtests and EF involvement in the Perceptual Organization Index of the WAIS-III. Results are discussed as to the need for an integrated, multifaceted view on cognitive disorders and intellectual (dis)abilities.