Intelligence and Reaction Time: The Contribution of Arthur Jensen
The second way of looking at Jensen’s contribution is much more interesting and important, and it goes back to the very beginning of intelligence testing, namely the two contrasting and conflicting paradigms of intelligence produced by Sir Francis Galton, on the one hand, and Alfred Binet, on the other. Essentially these two men differed on three main points, and the debate which they inaugurated has resounded through the corridors of academic research and theorizing ever since (Eysenck, 1986; Eysenck and Barrett, 1985.)
The first important difference concerns the notion of ‘intelligence’ itself. For Galton intelligence was an all-encompassing faculty of the mind, entering into all cognitive processes, and differing quantitatively from one person to another. He was thus an early advocate of what might now be called ‘latent trait’ theory, i.e., attempting to explain phenotypical behaviour in terms of underying traits or abilities. Binet, on the other hand, was far more impressed with the diversity of cognitive performances, and posited a large number of different abilities which were relatively independent. Intelligence, so he thought, was merely the average of all these abilities shown by a given child; in a very real sense it was thus a statistical artifact, and possessed no true uniformity or scientific standing. Binet’s theory suggests that the term ‘intelligence’ is a misnomer, as it does not in any meaningful sense exist to explain all types of cognitive phenomena.