Thurstone Primary Mental Abilities: First multi-factor IQ battery

About the Thurstone Primary Mental Abilities

By the 1930s the major question in intelligence research was whether there was one general intelligence factor (Charles Spearman's g) or multiple independent abilities. Spearman's view dominated in the UK; American psychologists were more skeptical. Louis Thurstone, at the University of Chicago, set out to settle the question empirically.

Thurstone administered 57 cognitive tests to a large sample of students and applied his new multiple-factor analysis method (a major statistical innovation he had developed). The result was 7 distinct, weakly-correlated factors: Verbal Comprehension (V), Word Fluency (W), Number (N), Spatial Visualization (S), Associative Memory (M), Perceptual Speed (P), and Reasoning (R). He called these the Primary Mental Abilities.

Thurstone's 7-factor model directly competed with Spearman's general-factor view through the 1940s and 1950s. The eventual synthesis (Cattell-Horn-Carroll model, 1990s-2000s) accepted both: there IS a general factor at the top, AND there are distinct broad abilities below it. But Thurstone's empirical demonstration that intelligence is multi-dimensional shaped every modern cognitive battery, including the WAIS-IV, WISC-V, and Stanford-Binet 5.

The 7 subtests

Take the interactive subset

Sample items from each of Thurstone's 7 factors. The original PMA battery had several specific tests per factor.

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Source

All test materials and historical content on this page are transcribed from:

Thurstone, L. L. (1938). Primary Mental Abilities. Psychometric Monographs No. 1. Chicago: University of Chicago Press.

Louis Thurstone (1887-1955) was the most influential American psychometrician of the 20th century. The PMA monograph is one of the most-cited papers in the history of psychology. Read it on Internet Archive: https://archive.org/details/primarymentalabi0000llth.