Education, Wechsler's full scale IQ, and g

The scientific construct of general intelligence (g) rests on the correlations among test scores, while IQ rests on the summation of standardized scores. Although IQ is usually considered a fine-grained proxy measure of general intelligence, IQ is actually an arbitrary variable (intelligence in general) not a scientific construct (general intelligence). This study examines the question of whether or not average Full Scale IQ (FSIQ) differences between groups that differ in their academic level can be attributed to g, because IQ results from g plus a mixture of specific cognitive abilities and skills. The Spanish standardization sample of the Wechsler Adult Intelligence Scale (WAIS-III) is analyzed. The sample comprised 703 females and 666 men aged 15-94 drawn as representative of the population in forms of educational level and geographical location. The results support the conclusion that the Wechsler FSIQ does not directly or exclusively measure g across the full range of the population distribution of intelligence. There is no significant association between the scientific construct of general intelligence (g) and the differences in intelligence in general (IQ) assessed by the WAIS-III. Some theoretical conclusions are stated as consequence of this lack of association. (C) 2002 Elsevier Science Inc. All rights reserved.