Charles Spearman

Charles Edward Spearman, FRS (10 September 1863 - 17 September 1945) was an English psychologist known for work in statistics, as a pioneer of factor analysis, and for Spearman's rank correlation coefficient. He also did seminal work on models for human intelligence, including his theory that disparate cognitive test scores reflect a single general factor and coining the term g factor.

Biography

Spearman had an unusual background for a psychologist. After 15 years as an officer in the British Army he resigned to study for a PhD in experimental psychology. In Britain, psychology was generally seen as a branch of philosophy and Spearman chose to study in Leipzig under Wilhelm Wundt, because Spearman had no conventional qualifications and Leipzig had liberal entrance requirements. He started in 1897, and after some interruption (he was recalled to the army during the South African War) he obtained his degree in 1906. He had already published his seminal paper on the factor analysis of intelligence (1904). Spearman met and impressed the psychologist William McDougall who arranged for Spearman to replace him when he left his position at University College London. Spearman stayed at University College until he retired in 1931. Initially he was Reader and head of the small psychological laboratory. In 1911 he was promoted to the Grote professorship of the Philosophy of Mind and Logic. His title changed to Professor of Psychology in 1928 when a separate Department of Psychology was created.

When Spearman was elected to the Royal Society in 1924 the citation read "Dr. Spearman has made many researches in experimental psychology. His many published papers cover a wide field, but he is especially distinguished by his pioneer work in the application of mathematical methods to the analysis of the human mind, and his original studies of correlation in this sphere. He has inspired and directed research work by many pupils." Chief amongst these achievements was the discovery of the general factor in human intelligence (Spearman, 1904), and his subsequent development of a theory of "g" (Spearman, 1923) and synthesis of empirical work on ability (Spearman, 1927) .

Spearman was strongly influenced by the work of Francis Galton. Galton did pioneering work in psychology and developed correlation, the main statistical tool used by Spearman.

In statistics, Spearman developed rank correlation (1904), a non-parametric version of the conventional Pearson correlation, as well as both the widely used correction for attenuation (1907), and the earliest version of a ‘factor analysis’ (Lovie & Lovie, 1996, p. 81) . His statistical work was not appreciated by his University College colleague Karl Pearson and there was a long feud between them.

Although Spearman achieved most recognition in his day for his statistical work, he regarded this work as subordinate to his quest for the fundamental laws of psychology, and he is now similarly renowned for both.

Theory of intelligence

Spearman contrasted meaning-making ability (eduction) and memory (reproduction), arguing that to understand their "respective natures" would be for the study of individual differences, and even cognition itself, "the very beginning of wisdom.".

A wonderful record of Spearman's views on g (and also those of Godfrey Thomson and Edward Thorndike) was made in the course of the Andrew Carnegie sponsored International Examinations Inquiry Meetings .

Here, Spearman gives a compact summary of his findings and theory of g:

When asked what G is, one has to distinguish between the meanings of terms and the facts about things. G means a particular quantity derived from statistical operations. Under certain conditions the score of a person at a mental test can be divided into two factors, one of which is always the same in all tests, whereas the other varies from one test to another; the former is called the general factor or G, while the other is called the specific factor. This then is what the G term means, a score-factor and nothing more. But this meaning is sufficient to render the term well defined so that the underlying thing is susceptible to scientific investigation; we can proceed to find out facts about this score-factor, or G. We can ascertain the kind of mental operations in which it plays a dominant part as compared with the other or specific factor. And so the discovery has been made that G is dominant in such operations as reasoning, or learning Latin; whereas it plays a very small part indeed in such operation (sic) as distinguishing one tone from another. . . G tends to dominate according as the performance involves the perceiving of relations, or as it requires that relations seen in one situation should be transferred to another. . . . On weighing the evidence, many of us used to say that this G appears to measure some form of mental energy. But in the first place, such a suggestion is apt to invite needless controversy. This can be avoided by saying more cautiously that G behaves as if it measured an energy. In the second place, however, there seems to be good reason for changing the concept of energy to that of “power” (which, of course, is energy or work divided by time). In this way, one can talk about mind power in much the same manner as about horse power. . . . . . .G is in the normal course of events determined innately; a person can no more be trained to have it in higher degree than he can be trained to be taller. (pp. 156 –157).

Despite Spearman arguing that g was what emerged from a large battery of tests, i.e., that it was not measured perfectly by any single test, the fact that g-theory suggested that much of ability could be captured in a single factor and Spearman's suggestion that “the eduction of relations and correlates” underlay this general factor lead to the development of tests for general ability such as Raven's Progressive Matrices (although Raven himself clearly stated that this test should not be regarded as an intelligence test).

While arguing consistently that g accounted for much of individual differences in ability, he also acknowledged that “Every normal man, woman, and child is … a genius at something … It remains to discover at what …" He thought that detecting these areas of genius required procedures very differnt from "any of the testing procedures at present in current usage", though he felt these to be capable of "vast improvement”.

Like Arthur Jensen after him, Spearman felt that though g could be detected in any broad set of cognitive measures, that testing for g “had no place in schools” as it "deflected" teachers, pupils, and politicians attention from the business of education which, as the Latin root of the word implies, involves "drawing out" whatever talents a student may have .

Spearman's model was influential, but was also critiqued by many authors, such as, for instance Godfrey Thomson . In particular the move from a psychological g to a biological g – that is a unitary biological mechanism or mechanisms has remained a matter of active research.

Factor analysis

Factor analysis is a statistical test that is used to find relationships between multiple correlated measures and Spearman played a clear part in its development. Spearman coined the term factor analysis and used it extensively in analysing multiple measure's of cognitive performance. It was factor analytic data which lead Spearman to postulate his original general and specific factor models of ability.. Factor analysis and its modern relations confirmatory factor analysis and Structural equation modelling underly much of modern behaviour research.

Works

• "General Intelligence," objectively determined and measured. "American Journal of Psychology" 1904
• Proof and measurement of association between two things. "American Journal of Psychology" 1904
• Demonstration of Formulae for True Measurement of Correlation. "American Journal of Psychology" 1907
• Spearman, Charles (1927). The Abilities of Man: Their Nature and Measurement. New York (NY): Macmillan. p. 221. Every normal man, woman, and child is, then, a genius at something, as well as an idiot at something. {{cite book}}: Invalid |ref=harv (help)

Biographies of Spearman

• Lovie, P and Lovie A. D. (1996) Charles Edward Spearman F.R.S. (1863–1945) Notes and Records of the Royal Society of London, 50, 1-14.
• Lovie, P (1997) Spearman, Charles Edward pp. 342–3 in Leading Personalities in Statistical Sciences from the Seventeenth Century to the Present, (ed. N. L. Johnson and S. Kotz) 1997. New York: Wiley. Originally published in Encyclopedia of Statistical Science.

Further reading

• Gregory, Robert J. (2011). Psychological Testing: History, Principles, and Applications (Sixth ed.). Boston: Allyn & Bacon. ISBN 978-0-205-78214-7. {{cite book}}: Invalid |ref=harv (help); Unknown parameter |laydate= ignored (help); Unknown parameter |laysummary= ignored (help)

• Mackintosh, N. J. (1998). IQ and Human Intelligence. Oxford: Oxford University Press. ISBN 978-0-19-852367-3. {{cite book}}: Invalid |ref=harv (help); Unknown parameter |laydate= ignored (help); Unknown parameter |laysummary= ignored (help)

External links

Spearman's 1904 General Intelligence paper is available on the Classics in the History of Psychology website.

• General Intelligence
• Charles Spearman at Human Intelligence

There is an account of Spearman's main achievements in

• Williams, R. H., Zimmerman, D. W., Zumbo, B. D. & Ross, D. (2003). Charles Spearman: British Behavioral Scientist. Human Nature Review. 3: 114-118

There is a photograph of Spearman at

• Charles Spearman on the Portraits of Statisticians page.