The significance of the dispute between Charles Spearman and Godfrey Thomson over the role of factor analysis in providing unambiguous evidence for Spearman’s two-factor theory has not been recognised for the crucial moment it actually was in the history of psychometrics. Thomson sketched an alternative to Spearman’s theory demonstrating that, factor analysis notwithstanding, there was no need to hypothesise that abilities are quantitative attributes. Spearman was blind to this fact and his stature within the discipline ensured that Thomson’s alternative was subsequently neglected. I argue that Spearman’s blindness was conditioned by his fealty to two idols of the age: the quantitative imperative and the psychometricians’ fallacy, both of which were secured in Spearman’s mind by his failure to fully understand the concept of measurement. Given his influence, Spearman’s blindness to the significance of Thomson’s critique was a cause of psychometrics’ relentless progress to becoming a pathological science.
AraujoS. F.MarcellosC. F. (2017). From classicism and idealism to scientific naturalism: Titchener’s Oxford years and their impact upon his early intellectual development. History of Psychology, 20(2), 148–171. https://doi.org/10.1037?HOP0000059
2.
BaldwinJ. M. (1901). Factor. In BaldwinJ. M. (Ed.), Dictionary of philosophy and psychology (Vol. 1, p. 368). Macmillan.
3.
BergsonH. (1913). Time and free will: An essay on the immediate data of consciousness (PogsonF. L., Trans.). George Allen & Co. (Original work published 1889)
4.
BlinkhornS. F. (1995). Burt and the early history of factor analysis. In MackintoshN. J. (Ed.), Cyril Burt: Fraud or framed (pp. 13–44). Oxford University Press.
CattellJ. M. (1902). Measurement. In BaldwinJ. M. (Ed.), Dictionary of philosophy and psychology (Vol. 2, p. 57). Macmillan.
11.
DearyI. J.LawnM.BrettC. E.PattieA.BartholomewD. J. (2010). Archival sources for Sir Godfrey Hilton Thomson. History of Psychology, 13(1), 95–109. https://doi.org/10.1037/a0018529
GaltonF. (1883). Inquiries into the human faculty and its development. Macmillan.
21.
GaukrogerS. (2020). Civilization and the culture of science: Science and the shaping of modernity 1795–1935. Oxford University Press.
22.
GraysonD. A. (2006). Might “unique” factors be “common”? On the possibility of indeterminate common-unique covariances. Psychometrika, 71(3), 521–528. https://doi.org/10.1007/s11336-002-1024-1
23.
GuilfordJ. P. (1967). The nature of human intelligence. McGraw-Hill.
HeathT. L. (1908). The thirteen books of Euclid’s elements (Vol. 2). Cambridge University Press.
26.
HogbenL. (1957). Statistical theory: The relationship of probability, credibility and error. George Allen & Unwin.
27.
HölderO. (1901). Die Axiome der Quantität und die Lehre vom Mass [The axioms of quantity and the theory of measurement]. Berichte über die Verhandlungen der Königlich Sächsischen Gesellschaft der Wissenschaften zu Leipzig, Mathematisch-Physische Klasse, 53, 1–46.
28.
HölderO. (2013). Intuition and reasoning in geometry (CantùP.SchlaudtO., Trans.). Philosophia Scientiæ, 17(1), 15–52. https://doi.org/10.4000/philosophiascientiae.836 (Original work published 1899)
MichellJ. (2009a). Invalidity in validity. In LissitzR. W. (Ed.), The concept of validity (pp. 111–133). Information Age Publishing.
35.
MichellJ. (2009b). The psychometricians’ fallacy: Too clever by half?British Journal of Mathematical and Statistical Psychology, 62(1), 41–55. https://doi.org/10.1348/000711007X243582
36.
MichellJ. (2012). Alfred Binet and the concept of heterogeneous orders. Frontiers in Psychology, 3, Article 26. https://doi.org/0.3389/fpsyg.2012.00261
MichellJ. (2022). “The art of imposing measurement upon the mind”: Sir Francis Galton and the genesis of the psychometric paradigm. Theory & Psychology, 32(3), 375–400. https://doi.org/10.1177/0959354311017671
39.
NiallK. K. (1995). Conventions of measurement in psychophysics: von Kries on the so-called psychophysical law. Spatial Vision, 9(3), 275–305. https://doi.org/10.1163/156856895X00016
PetoczA.NewberyG. (2010). On conceptual analysis as the primary qualitative approach to statistics education research in psychology. Statistics Education Research Journal, 9(2), 123–145. https://doi.org/10.52041/serj.v9i2.380
44.
ReadC. (1878). On the theory of logic: An essay. C. Kegan Paul & Co.
SpearmanC. (1904a). General intelligence, objectively determined and measured. American Journal of Psychology, 15(2), 201–293. https://doi.org/10.2307/1412107
47.
SpearmanC. (1904b). The proof and measurement of association between two things. American Journal of Psychology, 15(1), 72–101. https://doi.org/10.2307/1412159
SpearmanC. (1908). The method of “right and wrong cases” (“constant stimuli”) without Gauss’s formulae. British Journal of Psychology, 2(3), 227–242. https://doi.org/10.1111/j.2044-8295.1908.tb00176.x
50.
SpearmanC. (Chair). (1913). Are the intensity differences of sensations quantitative? [Symposium]. Joint Session of the Aristotelian Society, the British Psychological Society, and the Mind Association. Proceedings of the Aristotelian Society, 13(1), p. 365. Oxford University Press.
51.
SpearmanC. (1914). The heredity of abilities. The Eugenics Review, 6(3), 219–237.
52.
SpearmanC. (1915). The measurement of intelligence. The Eugenics Review, 6(4), 312–313.
53.
SpearmanC. (1923). The nature of “intelligence” and the principles of cognition. Macmillan.
54.
SpearmanC. (1925). Some issues in the theory of “g” (including the law of diminishing returns). Nature, 116(2916), 436–439. https://doi.org/10.1038/116436a0
SpearmanC. (1929b). The tenth Maudsley lecture: The psychiatric use of the methods and results of experimental psychology. The Journal of Mental Science, 75(310), 357–370. https://doi.org/10.1192/bjp.75.310.357
59.
SpearmanC. (1930a). C. Spearman. In MurchisonC. (Ed.), A history of psychology in autobiography (Vol. 1, pp. 299–333). Clark University Press.
60.
SpearmanC. (1930b). “G” and after—A school to end schools. In MurchisonC. (Ed.), Psychologies of 1930 (pp. 339–366). Clark University Press.
61.
SpearmanC. (1931). Our need of some science in place of the word “intelligence.”Journal of Educational Psychology, 22(6), 401–410. https://doi.org/10.1037/h0070599
62.
SpearmanC. (1937a). Psychology down the ages (Vol. 1). Macmillan.
63.
SpearmanC. (1937b). Psychology down the ages (Vol. 2). Macmillan.
SteigerJ. H. (1996). Coming full circle in the history of factor indeterminacy. Multivariate Behavioral Research, 31(4), 617–630. https://doi.org/10.1207/s15327906mbr3104_14
ThomsonG. H. (1921). Preface II. In BrownW.ThomsonG. H. (Eds.), The essentials of mental measurement (pp. vi–viii). Cambridge University Press.
72.
ThomsonG. H. (1939). The factorial analysis of human ability. University of London Press.
73.
ThomsonG. H. (1946). Some recent work in factorial analysis, and a retrospect. University of London Press.
74.
ThomsonG. H. (1952). Godfrey Thomson. In BoringE. G.WernerH.LangfeldH. S.YerkesR. M. (Eds.), A history of psychology in autobiography (Vol. IV, pp. 279–294). Clark University Press.
75.
ThurstoneL. L. (1947). Multiple-factor analysis: A development and expansion of the vectors of the mind. University of Chicago Press.
76.
TitchenerE. B. (1905). Experimental psychology: A manual of laboratory practice: Vol. 2. Quantitative experiments: Part 2. Instructor’s manual. Macmillan.
77.
TitchenerE. B. (1921). [Review of the book Erlebtes und Erkanntes, by W. Wundt]. American Journal of Psychology, 32(4), 575–580. https://www.jstor.org/stable/1413778
78.
von HelmholtzH. (1971). An epistemological analysis of counting and measurement. An essay contributed to the Festschrift honoring Eduard Zeller in 1887 (KahlR., Trans.). In KahlR. (Ed.), Selected writings of Hermann von Helmholtz (pp. 437–465). Wesleyan University Press. (Original work published 1887)
79.
von KriesJ. (1882). Über die Messung intensiver Grössen und über das sogenannte psychophysische Gesetz [On the measurement of intensive magnitudes and the so-called psychophysical law]. Vierteljahrsschrift für Wissenschaftliche Philosophie, 6, 257–294.
80.
WilsonE. B. (1928a). [Review of the bookThe Abilities of Man, their Nature and Measurement, by SpearmanC.]. Science, 67(1731), 244–248. http://www.jstor.org/stable/1654268
81.
WilsonE. B. (1928b). On hierarchical correlation systems. Proceedings of the National Academy of Sciences, 14(3), 283–291. https://doi.org/10.1073/pnas.14.3.283
82.
WiseM. N. (1995). Precision: Agent of unity and product of agreement. In WiseM. N. (Ed.), The values of precision (pp. 92–100). Princeton University Press.
83.
YakushkoO. (2019). Eugenics and its evolution in the history of western psychology: A critical archival review. Psychotherapy and Politics International, 17(2), 1–13. https://doi.org/10.1002/ppi.1495
