SPEARMAN AND THE "FACTOR" SCHOOL
SPEARMAN entered psychology relatively late in life, studying with Wundt and Müller after resigning a commission in the British Army--an unusual approach to the problems of the mind. In 1907 he was put in charge of a small and new psychological department at University College, London, in succession to McDougall; his laboratory being equipped for the most part with apparatus brought from the Freiburg laboratory vacated by Münsterberg, when the latter left for America. Here he remained till he, in his turn, left for America in 1931, and in his twenty-four years' work in London he founded one of the most important modern schools (the "Factor School", as it has been appropriately called in Psychologies of 1930), attracted numerous students from various parts of the British Empire and elsewhere, and, together with them, produced a very large quantity of work, much of which was embodied in his two important books, The Nature of Intelligence and the Principles of Cognition and The Abilities of Man, published in 1923 and 1927 respectively.
Already in 1904, however, he had published an article in the American Journal of Psychology, which adumbrated the most important portion of his doctrine. This doctrine implies the existence, on the one hand, of a general factor of ability (subsequently called g), varying in power from one individual to another, but operative to some extent in all performances; and, on the other hand, of a large number of highly specific abilities (collectively called s), some