The idea of IQ / Russell Marks.

  • Marks, Russell.
Date:
[1981], ©1981
Catalogue details

Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: The idea of IQ / Russell Marks. Source: Wellcome Collection.

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    McKeen Cattell, the eminent American psychologist who coined the terms individual differences and mental tests, pinpointed the essential features of this new perspective in a 1916 address celebrating the twenty- fifth anniversary of the American Psychological Asso¬ ciation. The perspective sought to ally psychology and its methods with the natural and exact sciences rather than with philosophy; to replace intro¬ spection and verbal descriptions by experiments and measurements; to in¬ vestigate behavior and conduct rather than the mind and consciousness; to study individual and group differences; to make practical applications and devel¬ op a profession of applied psychology.^ Despite competing schools, this model came to dominate psychology. Drawing on theory and methods from evolu¬ tionary theory and the physical and natural sciences, American psychologists sought to create a science of psychology. The construct of individual differences was their fundamental accomplishment. It provided the basis for the claim that psychology was a science. It provided a common set of facts, methods, techniques, and theory for psychologists to build their discipline around and a common set of agreed-upon assumptions with¬ in which they could operate. It also basically allowed psychologists to abandon construct building and become puzzle solvers, which, as Thomas Kuhn notes, is the normal activity of scientists.* Psychologists * quest to create a scientific con¬ struct was an attempt to create a science of human na¬ ture. The central claim made about the construct of individual differences was that intelligence was essen¬ tially hereditary and that I.Q. tests basically measured hereditary, unmalleable intelligence. By this formula¬ tion, I.Q. tests provided not only a description of the individual's performance but a description of the indi¬ vidual's hereditary unmalleable potential. Yet these claims raised a number of difficult questions. How did psychologists know that intelligence, however they de¬ fined it, was essentially hereditary? How did psychol- -5-