Peter Schonemann
Encyclopedia
Peter H. Schönemann 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.
Schönemann died on April 7, 2010.
. Other Schönemann papers include "A generalized solution of the orthogonal Procrustes problem", "The minimum average correlation between equivalent sets of uncorrelated factors", and "Some new results on factor
indeterminacy
" 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.
. 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. 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 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.
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. 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. For example, the narrow heritabilities 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.
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
born psychometrician
Psychometrics
Psychometrics is the field of study concerned with the theory and technique of psychological measurement, which includes the measurement of knowledge, abilities, attitudes, personality traits, and educational measurement...
and statistical
Statistics
Statistics is the study of the collection, organization, analysis, and interpretation of data. It deals with all aspects of this, including the planning of data collection in terms of the design of surveys and experiments....
expert. He was Professor Emeritus in the Department of Psychological Sciences
Psychology
Psychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...
at Purdue University
Purdue University
Purdue University, located in West Lafayette, Indiana, U.S., is the flagship university of the six-campus Purdue University system. Purdue was founded on May 6, 1869, as a land-grant university when the Indiana General Assembly, taking advantage of the Morrill Act, accepted a donation of land and...
. His research interests included multivariate statistics
Multivariate statistics
Multivariate statistics is a form of statistics encompassing the simultaneous observation and analysis of more than one statistical variable. The application of multivariate statistics is multivariate analysis...
, multidimensional scaling
Multidimensional scaling
Multidimensional scaling is a set of related statistical techniques often used in information visualization for exploring similarities or dissimilarities in data. MDS is a special case of ordination. An MDS algorithm starts with a matrix of item–item similarities, then assigns a location to each...
and measurement, quantitative
Quantitative property
A quantitative property is one that exists in a range of magnitudes, and can therefore be measured with a number. Measurements of any particular quantitative property are expressed as a specific quantity, referred to as a unit, multiplied by a number. Examples of physical quantities are distance,...
behavior genetics, test
Test (assessment)
A test or an examination is an assessment intended to measure a test-taker's knowledge, skill, aptitude, physical fitness, or classification in many other topics . A test may be administered orally, on paper, on a computer, or in a confined area that requires a test taker to physically perform a...
theory
Theory
The English word theory was derived from a technical term in Ancient Greek philosophy. The word theoria, , meant "a looking at, viewing, beholding", and referring to contemplation or speculation, as opposed to action...
and mathematical tools for social scientists. He published around 90 papers dealing mainly with the subjects of psychometrics
Psychometrics
Psychometrics is the field of study concerned with the theory and technique of psychological measurement, which includes the measurement of knowledge, abilities, attitudes, personality traits, and educational measurement...
and mathematical scaling. Schönemann’s influences included Louis Guttman, Lee Cronbach
Lee Cronbach
Lee Joseph Cronbach was an American educational psychologist who made significant contributions to psychological testing and measurement. Born in Fresno, California, Cronbach was selected as a child to participate in Lewis Terman's long-term study of talented children...
, Oscar Kempthorne
Oscar Kempthorne
Oscar Kempthorne was a statistician and geneticist known for his research on randomization-analysis and the design of experiments, which had wide influence on research in agriculture, genetics, and other areas of science...
and Henry Kaiser
Henry Kaiser
Henry Kaiser may refer to:People*Henry Felix Kaiser , American academic known for the varimax rotation*Henry J. Kaiser , American industrialist and shipbuilder who founded Kaiser Permanente...
.
Schönemann was a persistent critic of what he considered to be scientifically sanctioned racism
Racism
Racism is the belief that inherent different traits in human racial groups justify discrimination. In the modern English language, the term "racism" is used predominantly as a pejorative epithet. It is applied especially to the practice or advocacy of racial discrimination of a pernicious nature...
in psychology
Psychology
Psychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...
. In particular, he claimed that (1) Arthur Jensen
Arthur Jensen
Arthur Robert Jensen is a Professor Emeritus of educational psychology at the University of California, Berkeley. Jensen is known for his work in psychometrics and differential psychology, which is concerned with how and why individuals differ behaviorally from one another.He is a major proponent...
and others routinely confuse the first principal component (PC1) with g
General intelligence factor
The g factor, where g stands for general intelligence, is a statistic used in psychometrics to model the mental ability underlying results of various tests of cognitive ability...
as Charles Spearman
Charles Spearman
Charles Edward Spearman, FRS was an English psychologist known for work in statistics, as a pioneer of factor analysis, and for Spearman's rank correlation coefficient...
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.
Schönemann died on April 7, 2010.
Education
- 1953–56 University of Munich (Vordiplom)
- 1956–59 University of Göttingen (Diplom)
- 1960–64 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 problemOrthogonal Procrustes problem
The orthogonal Procrustes problem is a matrix approximation problem in linear algebra. In its classical form, one is given two matrices A and B and asked to find an orthogonal matrix R which most closely maps A to B...
. Other Schönemann papers include "A generalized solution of the orthogonal Procrustes problem", "The minimum average correlation between equivalent sets of uncorrelated factors", and "Some new results on factor
Factor analysis
Factor analysis is a statistical method used to describe variability among observed, correlated variables in terms of a potentially lower number of unobserved, uncorrelated variables called factors. In other words, it is possible, for example, that variations in three or four observed variables...
indeterminacy
Indeterminacy
Indeterminacy or underdeterminacy may refer to:* Indeterminacy in computation * aleatoric music and indeterminacy in music.* Statically indeterminate*Indeterminacy a literary term...
" co-authored with M.M. Wang. Schönemann wrote also numerous book chapters, including the "Psychometrics of Intelligence
Intelligence
Intelligence has been defined in different ways, including the abilities for abstract thought, understanding, communication, reasoning, learning, planning, emotional intelligence and problem solving....
" chapter in Encyclopedia of Social Measurement and the “Heritability” chapter in Encyclopedia of Human Intelligence.
g theory
Schönemann argued for the non-existence of psychometric gGeneral intelligence factor
The g factor, where g stands for general intelligence, is a statistic used in psychometrics to model the mental ability underlying results of various tests of cognitive ability...
. He wrote that there is a fundamental difference between g, first defined by Charles Spearman
Charles Spearman
Charles Edward Spearman, FRS was an English psychologist known for work in statistics, as a pioneer of factor analysis, and for Spearman's rank correlation coefficient...
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. 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 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.
Twin studies
In a number of publications, Schönemann argued that the statistical heritabilityHeritability
The Heritability of a population is the proportion of observable differences between individuals that is due to genetic differences. Factors including genetics, environment and random chance can all contribute to the variation between individuals in their observable characteristics...
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. He argued that this was true for the monozygotic twins
TWINS
Two Wide-Angle Imaging Neutral-Atom Spectrometers are a pair of NASA instruments aboard two United States National Reconnaissance Office satellites in Molniya orbits. TWINS was designed to provide stereo images of the Earth's ring current. The first instrument, TWINS-1, was launched aboard USA-184...
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. For example, the narrow heritabilities 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.