Peter Hans Schönemann (July 15, 1929 – April 7, 2010) was a German-born psychometrician and statistical expert. He was professor emeritus in the Department of Psychological Sciences at Purdue University. His research interests included multivariate statistics, multidimensional scaling and measurement, quantitative behavior genetics, test theory and mathematical tools for social scientists. He published around 90 papers dealing mainly with the subjects of psychometrics and mathematical scaling. Schönemann's influences included Louis Guttman, Lee Cronbach, Oscar Kempthorne and Henry Kaiser.
Schönemann was a persistent critic of what he considered to be scientifically sanctioned racism in psychology. In particular, he claimed that (1) Arthur Jensen and others routinely confuse the first principal component (PC1) with g as Charles Spearman defined it, and that (2) the high IQ heritability estimates reported in the literature derive from restrictive formal models whose underlying assumptions are rarely tested and usually violated by the data.Models and muddles of heritability. Genetica, 99, 97–108 Factorial definitions of intelligence: Dubious legacy of dogma in data analysis. In I. Borg (Ed.), Multidimensional data representations: When and why. Ann Arbor: Mathesis Press, 325–374Schönemann, P. H. (1983). Do IQ tests really measure intelligence? Commentary, The Behavioral and Brain Sciences, 6, 311–313
Schönemann died on April 7, 2010.Peter Schönemann Obituary
Education 1953–1956 Ludwig-Maximilians-Universität München (Vordiplom) 1956–1959 University of Göttingen (Diplom) 1960–1964 University of Illinois (Ph.D. in General Psychology)
Notable work Schönemann's PhD thesis "A solution of the orthogonal Procrustes problem with applications to orthogonal and oblique rotation," proposed a solution to the orthogonal Procrustes problem. Other Schönemann papers include "A generalized solution of the orthogonal Procrustes problem",A generalized solution of the orthogonal Procrustes problem. Psychometrika, 31, 1–10.: "The minimum average correlation between equivalent sets of uncorrelated factors",The minimum average correlation between equivalent sets of uncorrelated factors. Psychometrika, 36, 21–30.: and "Some new results on factor indeterminacy"Some new results on factor indeterminacy. Psychometrika, 37, 61–69 co-authored with M.M. Wang. Schönemann wrote also numerous book chapters, including the "Psychometrics of Intelligence" chapter in Encyclopedia of Social Measurement and the "Heritability" chapter in Encyclopedia of Human Intelligence.Peter H. Schönemann (1994). Heritability. In R Sternberg (Ed.), Encyclopedia of Human Intelligence. New York: McMillan, p. 528–536.
g theory Spearman's hypothesis asserts a correlation between the g-loadedness of IQ tests and measures of their heritability, a concept put to work in Arthur Jensen's discussion of black—white race differences from the 1980s. Schönemann regarded this work as resting on a conceptual confusion.
Schönemann argued for the non-existence of psychometric g. He wrote that there is a fundamental difference between g, first defined by Charles Spearman as a latent one-dimensional variable that accounts for all correlations among any intelligence tests, and a first principal component (PC1) of a positive correlation matrix. Spearman's tetrad difference equation states a necessary condition for such a g to exist.Famous artefacts: Spearman's Hypothesis. Cahiers de Psychologie Cognitive / Current Psychology of Cognition, 16, 665–698: The important proviso for Spearman's claim that such a g qualifies as an "objective definition" of "intelligence", is that all correlation matrices of "intelligence tests" must satisfy this necessary condition, not just one or two, because they are all samples of a universe of tests that are subject to the same g. Schönemann argued that this condition is routinely violated by all correlation matrices of reasonable size, and thus, such a g does not exist.Psychometrics of Intelligence. K. Kemp-Leonard (ed.) Encyclopedia of Social Measurement, 3, 193–201:
Twin studies In a number of publications, Schönemann argued that the statistical heritability estimates used in most twin studies rest on restrictive assumptions which are usually not tested, and if they are, often are found to be violated by the data.Schönemann, P. H. & Schönemann, R. D. (1994). Environmental versus genetic models for Osborne's personality data on identical and fraternal twins. Cahiers de Psychologie Cognitive – Current Psychology of Cognition 13, 141–167: He argued that this was true for the monozygotic twins raised apart vs. together (MZT) studies (Burt, Shields, Jinks and Fulker, Bouchard) as well as for the more widely used MZT vs dizygotic twins raised together studies.Schönemann, P. H.(1994).Heritability. In R Sternberg (Ed.), Encyclopedia of Human Intelligence. New York: McMillan, p. 528–536. For example, the narrow heritability of responses to the question "did you have your back rubbed" work out to 0.92 heritable for males and 0.21 heritable for females. Using the statistical models published in Loehlin and Nichols (1976) the question "Did you wear sunglasses after dark?" is 130% heritable for males and 103% for females.Totems of the IQ Myth: General Ability (g) and its Heritabilities (h2, HR). 1995 Meetings of the American Association for the Advancement of Sciences
References
External links Schönemanns' publication list Power Tables for Analysis of Variance Alternative measures of fit for the Schönemann-carroll matrix fitting algorithm Complexity, extremity, and affect in male and female judgments