In genius studies, historiometric method (LH:3), aka “historiometry” (Simonton, 2008) or "historiometric analysis", refers to the method "evaluating intelligence through biographical material" (Cox, 1926), i.e. of determining IQs of historical figures, particularly eminent ones, or established historical geniuses, based on their intellectual ability and accomplishments, per age period, e.g. youth, young adult, mature adult, wisdom-age adult, etc., and or summing the mean total "retrospect IQ", for all age periods of the person, based on extant existographical material, in respect to the IQ of average or typical person (mean: 100), in that respective age group. This method of "biographical evaluation of IQ", was pioneered by Lewis Terman in his 1917 attempts to estimate the IQ of Francis Galton.
In 1917, Lewis Terman, in his “The Intelligence Quotient of Francis Galton in Childhood”, after inventing his IQ scale and "IQ" determination, via his intelligence testing and mental age method, the previous year, sought to apply this method to the calculation of IQs of historical figures, which he did by using Karl Pearson's The Life, Letters and Labors of Francis Galton, Volume One, and from the facts detailed therein, such as the following:
- “I am four years old and I can read any English book. I can say all the Latin substantives and adjectives and active verbs besides fifty-two lines of Latin poetry. I can cast up any sum in addition and can multiply by 2, 3, 4, 6, 8, 9, 10, 11. I can also say the pence table. I read French a little and know the clock.”
- — Francis Galton (1826), “Summary of my Abilities at age 4-years and 365-days”
Determined that "Galton as a child had an intelligence quotient not far from 200, i.e. his ‘mental age’ was about twice his actual age". This Galton IQ calculation was the first-ever calculation of an IQ of an historical person. While this assignment of an IQ of 200 to Galton has been much ridiculed (see: Galton's IQ), in the century to follow, it provided a basic roadmap, outline, and or systematic way to calculate IQs of any historical figure, provided that enough existographical material is available.
In 1921, Terman, aware that his previous calculation of the IQ of Galton might have been biased:
- “Lombroso long ago [The Man of Genius (1896)] taught us that by sufficiently biased selection, it is possible to ‘prove’ almost any theory regarding genius, however bizarre.”
- — Lewis Terman (1926), “Editor’s Preface” (pg. vi) in: Early Mental Traits of 300 Geniuses
obtained a grant to do a larger scale calculation of the IQs of 300 historical figures, selected from the "objective" Cattell 1000 rankings, i.e. those of adulthood age in the years 1350 to 1850, and to have the IQs determined, via this so-called "historiometric method", independently by three different IQ estimators, namely: Terman, Catherine Cox, and Maud Merrill, each experienced with administering IQ tests to children, and to mean the resulting score. The project took five years, involving more than a dozen people, including Lela Gillan and Ruth Livesay, who spent a year amassing a 6,000-page report on the existographical accomplishments of the 300 selected historical "geniuses", from the Cattell list, amounting to about 20-pages for each subject. Terman comments on this:
- “The second task was to search the biographies of each of the subjects for evidence bearing on the superior already or inferiority of mental performances as judged by comparison with the performance of average children of corresponding age.”
- — Lewis Terman (1926), “Editor’s Preface” (pg. vii) in: Early Mental Traits of 300 Geniuses
To this end, Terman, Cox, and Merrill, independently, calculated the IQ of each eminent person, in two age periods: AI IQ (age: 1-16 or childhood and early youth) and AII IQ (age: 17 to mid-20s or first period of young adulthood), some of which are shown adjacent.
In 1924, Cox, in her The Early Mental Development of a Group of Eminent Men, presented a preliminary report of their findings, as her PhD thesis.
In 1925, Terman, in his Mental and Physical Traits of a Thousand Gifted Children, Genetic Studies of Genius, Volume One, summarized traits of 1,000 children that tested in the top 1% of his Stanford-Binet testings.
In 1926, Cox, in her Early Mental Traits of Three Hundred Geniuses, Genetic Studies of Geniuses, Volume Two, presented the finalized results of their historiometric calculation of IQs of "eminent men" or "geniuses", the fruit of which was the so-called "Cox 300", showing the AII IQs of the three hundred geniuses, which provided for a neutral benchmark IQ scale, as a first approximation of the IQs of historical geniuses.
The following are related quotes:
- “Terman is responsible for suggesting the novel method, adopted in this work, of evaluating intelligence through biographical material.”
- “The second volume in the five-volume Genetic Studies of Genius would seem to support the IQ definition of genius. Indeed, it is the only volume of the five to have "genius" in its title, rather than just "gifted." Called The Early Mental Traits of Three Hundred Geniuses, it is highly unique in four other ways as well. First, it is the only volume that does not include Terman as author or coauthor, but instead was solely authored by his graduate student, Catharine Cox, for her doctoral thesis! Second, it was the sole volume that did not use the sample of intellectually gifted children, but instead collected a sample that included indubitable geniuses, such as: Nicholas Copernicus, Charles Darwin, Rene Descartes, Galileo Galilei, Christian Huygens, Antoine Lavoisier, Justus Liebig, Carolus Linnaeus, Isaac Newton, and James Watt. If these scientists and inventors cannot be considered ‘geniuses’, then the term has no meaning. Third, because these historical figures were deceased at the time of her investigation, they could not take the Stanford-Binet intelligence test that provided the ultimate basis for the other four volumes. Nevertheless, she estimated IQ scores for each but did so using retrospective methods. In particular, where volumes 1, 3, 4, and 5 used psychometric methods, embodied in the IQ test, Cox used historiometric methods based on biographical data.”
- Terman, Lewis. (1917). “The Intelligence Quotient of Francis Galton in Childhood” (GB), American Journal of Psychology, 28: 209-15.
- Pearson, Karl. (1914). The Life, Letters and Labors of Francis Galton, Volume One. Cambridge, 2011.
- Cox, Catharine. (1926). Genetic Studies of Genius. Volume II. The Early Mental Traits of Three Hundred Geniuses (Editor's Preface, pgs. v-ix, Galton IQ of 200, pg. v) (GB) (Arc) (pdf) (ratings, pg. viii). Stanford University Press.
- Cesare Lombroso – Wikipedia.
- Lombroso, Cesare. (1896). The Man of Genius. Scott.
- Cox, Catharine. (1926). Genetic Studies of Genius. Volume II. The Early Mental Traits of Three Hundred Geniuses (GB) (Arc) (pdf) (ratings, pg. viii). Stanford University Press.
- (a) Cox IQ (subdomain) – Hmolpedia 2020.
(b) Cox IQs – IQComparisonSite.com.
- Simonton, Dean. (2016), “Reverse Engineering Genius: Historiometric Studies of Superlative Talent” (pdf), Annals of the New York Academy of Science, xxxx:1-7.
- Simonton, Dean. (2008). “A Reflective Conversation with Dean Keith Simonton” (pdf), North American Journal of Psychology, 10(3):595-602.
- Historiometry – Wikipedia.