He explored the statistical interrelations of scores on various tests and concluded that a positive correlation between any two mental functions must be attributed to the gfactor, since s factors have low correlations among them. The science of mental ability human evolution, behavior, and intelligence 9780275961039. His work on the classical test theory, factor analysis, and the g theory of intelligence continues to in. Multigroup covariance and mean structure modeling of the. It can serve as a long, good, but a bit dated introduction to the subject. It is a variable that summarizes positive correlations among different cognitive tasks, reflecting the fact that an individuals performance on one type of cognitive task tends to be. Precast concrete is our only business, and our 50 years of expertise reflects that singular concentration. In this paper i derive a riskadjusted measure of portfolio performance now known as jensen s alpha that estimates how much a managers forecasting ability contributes to the funds returns. Charles spearman william revelle northwestern university charles spearman 18631945 was the leading psychometrician of the early 20th century. Because all cognitive tests, from the simplest to the most complex, regardless of their informational content, are g. Charles spearman, gave this theory of g factor using factor analysis, which was later revised to two factor theory g factor and s factor.
Some of us are taller, betterlooking, darker, lighter, more. Jensen effects refer to the tendency for the tests g. The book deals with the intellectual history of the discovery of g and various models of how to conceptualize intelligence, and with the biological correlates of g, its heritability. The results are of theoretical interest in the light of the ankneyrushton paradox, and the role of g in educational attainment.
The science of mental ability 1998 is a book on the general intelligence factor g. Oct 22, 2012 arthur robert jensen was born august 24, 1923, in san diego, california, the son of linda mary nee schachtmayer and arthur alfred jensen, who operated and owned a lumber and building materials company. In factor analyses of any and every large and diverse collection of measures of mental abilities, however varied the content of knowledge. The g factor has been found to be largely invariant across different factor analytic methods and in different racial and cultural groups. Jensen argues that orthogonal rotation is not appropriate for substantially positively correlated variables such as mental abilities. Jensen of the university of california at berkeley and john b.
How to reference and link to summary or text g can be derived as the principal factor from cognitive test scores using the method of principal components analysis or factor analysis. Charles spearman first described the existence of general intelligence in 1904. When looking at the subtests of an iq battery these subtests range from high complexity high loadings on the g factor of intelligence to low complexity low loadings on the g factor. The measure is based on the theory of the pricing of capital assets by sharpe 1964, lintner 1965a and treynor undated. Indeed, much of the oppo sition to iqtesting and heritability would probably disappear if it were not for the stubborn and unwelcome fact that, despite extensive wellfunded programs of intervention, the blackwhite difference refuses to go quietly into the. Jensen accepts spearmans idea of a general factor in human intelligence, and his own theory divides intelligence into two distinct sets of abilities. The general despite some popular assertions, a single. In the spring of 1996, a new book about intelligence and education, the g factor, created shock waves in britain by tracing educational failure largely to genetic deficiency in mental speed. The g factor general mental abilityis the major construct for understanding both individual differences and the average differences between groups race and sex in educational and occupational attainment. He virtually singlehandedly resurrected the scientific study of intelligence, and he has been at the center of many breakthroughs in this field.
The science of mental ability 1998 is considered by supporters to be jensen s magnum opus on the general intelligence factor g. The memory factor could not emerge because the digit span subtest was not. The performance of mutual funds in the period 19451964 by. Arthur jensens research on the biological basis of mental ability has culminated in his encyclopedic new work the g factor 1998 which massively confirms. We are forced to infer that g is of considerable importance in real life by the fact that g constitutes the largest component of total variance in all standard tests of intelligence or iq, and the very. We give a series of necessary conditions for hamiltonicity which converges to hamiltonicity. The science of mental ability, examines the historical evolution of the g factor as well as many of the modernday implications of this development for psychologists. Introduced at the turn of the century by british psychologist charles spearman, factor analysis determines the minimum number of underlying dimen. He believed that theres one general intelligence which include mental operations that are primary in natur. Thus, a possible role of the factor v leiden mutation in the pathogenesis of infectious disease remains unclear.
Gottfredson school of education university of delaware g is a highly general capability for processing complex information of any type. The jensen effect and the spearmanjensen hypothesis of. Jensen explains how the general mental ability factor, g, is derived from factor analyses of large and diverse sets of mental tests, and why g provides a useful operational definition of intelligence. The jensen effect and the spearmanjensen hypothesis of black. General ability, defined as psychometric g, arises from the empirical fact that scores on various cognitive tests are positively correlated in the population. Jensen, jensenism, and the sociology of intelligence.
A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Rapid communication distributed brain sites for the gfactor of intelligence roberto colom,a rex e. But, as spearman observed, a general factor does emerge from analysis of mental ability tests, and leading psychologists, such as arthur r. Jensen fully and clearly explains the psychometric, statistical, genetic, and physiological basis of g, as well as the major theoretical challenges. Jensen precast is among the largest independently owned precast concrete companies in the united states. Publication date 1998 topics general factor psychology, intellect, nature and nurture. The general intelligence factor university of toronto.
The science of mental ability is a 1998 book by psychologist arthur jensen. Charles spearman originally suggested in 1927 that the varying magnitude of the mean difference between black and white populations on a variety of mental tests is directly related to the size of the tests loading on g, the general factor common to. Arthur jensens research on the biological basis of mental ability has culminated in his encyclopedic new work the g factor 1998 which massively confirms spearmans 1927 hypothesis that blackwhite iq differences vary systematically as a function of each tests g loading. Spearman reasoned that since the gfactor runs through all mental abilities and. The g factor arthur jensen clear language, clear mind. The jensen effect and the spearmanjensen hypothesis. In factor analyses of any and every large and diverse collection of measures of mental abilities, however varied the content of knowledge and skills. Jensen s the g factor all the issues jensen raised in 1969 are still with us today. However, the examination of jewish success has often focused. Spearman reasoned that since the gfactor runs through all mental abilities and predicts an individuals performance, it would be of no use to measure specific s factors, since each one. I definitely recommend reading it if one is interested in psychometrics. Because all cognitive tests, from the simplest to the most complex, regardless of their informational content, are gloaded to varying degrees, g cannot be described in terms of the tests content. Jensen to investigate the role of g in the relationship between iq subtest scores and other variables such as sex, race, scholastic achievement or educational attain.
General intelligence factor psychology wiki fandom. Perhaps the most important has been to turn the fields attention back to spearmans g, the general intelligence factor. The g factor also known as general intelligence, general mental ability or general intelligence factor is a construct developed in psychometric investigations of cognitive abilities and human intelligence. Psychometricians are generally agreed that a population difference in average test score is not, by itself, evidence of biased sampling of test items such as to favor or disfavor a particular cultural group. Whether we like it or not, we are all born with different characteristics, abilities and potentials. Many results of this chapter deal with generalizations of tournaments. Because all cognitive tests, from the simplest to the most complex, regardless of their. Jensen, the g factor, praeger publishers, 1998, 648 pp. Personality and individual differences vol 31, issue 8. Distributed brain sites for the gfactor of intelligence. The book deals with the intellectual history of g and various models of how to conceptualize intelligence, and with the biological correlates of g. An extensive exposition of g and its structure, heritability, biology, and correlates has been presented by jensen 1998 in his book the g factor. Horizontal and vertical aspects of g arthur jensen has reinvigorated and redirected the study of human intelligence in major ways.
A working definition of intelligence, then, is that it is the g factor of an indefinitely large and varied battery of mental tests. The implications of his findings for school psychologists are discussed, as are suggestions for future research. Jensens famous article on the heritability of iq and how difficult it is to raise. By submitting a comment you agree to abide by our terms and community guidelines. The science of mental ability 1998 by arthur robert jensen pdf, 51. The secular increase in test scores is a jensen effect. It does not draw back from its most controversial conclusionsthat the average differences in iq found between blacks and. The reader will see that several of these much larger classes of digraphs share various nice properties with tournaments. The jensen effect results from the correlation between the g factor and a huge number of psychological and biological variables. These specific factors refer to separate, single and specific activities and abilities. A life history perspective 2nd unabridged edition 1997 by john philippe rushton pdf, 27.
The definitive word on intelligence american renaissance. Blackwhite differences on the g factor in south africa. Berkeley is one of the greatest social scientists of our time. The analysis revealed the typical factor structure of the wisca large. We tested the hypothesis that the factor v leiden mutation influenced susceptibility to and mortality from infectious diseases. Conference on the g factor in employment testing 297. He looked at gender difference which found relatively little differences, heritability some evidence suggesting this, job performance highly predictive, etc. Secular gains in iq not related to the g factor and inbreding depression unlike blackwhite differences. Without a doubt the best about intelligence that i hav read so far.
Personality and individual differences, 34, 177183. The nature of the blackwhite difference on various. Jensen provides a comprehensive treatment of one of the major constructs of behavioral science. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate. The g factor is highly stable across different factor analytic algorithms, across different test batteries and across different populations. Jensen concluded from his research that level i abilities. Influence of the factor v leiden mutation on infectious. An examination of culture bias in the wonderlic personnel test. In factor analyses of any and every large and diverse collection of measures of mental abilities, however varied the. The g factor, the science of mental ability arthur r.
Level i abilities account for memory functions and simple associative learning, and level ii abilities comprise abstract reasoning and conceptual thought. Jensen has systematically researched and extended charles spearmans 1927 seminal concept of g, the general factor of intelligence. Jensen school of education, university of california, berkeley, california 94720, usa 1. A sketch of arthur jensen s contributions to the study of g philip a. General intelligence, also known as g factor, refers to the existence of a broad mental capacity that influences performance on cognitive ability measures. The book, by an edinburgh university academic, appeared after years in which educationalists and the media had played down to vanishing point the importance of. The jensen s measure is a riskadjusted performance measure that represents the average return on a portfolio or investment above or below that predicted by the capital asset. The correlations used for this factor analysis, all from one study, can be found in refs. Are cognitive g and academic achievement g one and the. In future, when a significant correlation occurs between gfactor loadings and variable x, the result might usefully be called a jensen effect for that x variable, because otherwise there is no name for it, only a long explanation of how the effect was achieved. And the sociology of intelligence 293 terns of evidence sooner and more clearly, and to suggest hypotheses that startled or unset tled the less prepared but that eventually became mainstream. The book is about the topic of the general factor of human mental. The g factor is a comprehensive analysis conducted by jensen look at the general intelligence across a wide range of factors and their implications. Received 8 january 2011 received in revised form 11 february 2011 accepted 11 march 2011 available online xxxx.
The g factor arthur r jensen bok 9780275961039 bokus. The g factor is about individual differences in mental abilities. The science of mental ability, arthur r jensen, politics and the life sciences, sept 1998 flynn effect links to loads of research examining the effect, or this. The g factor is an awesome and monumental exposition of the case for the reality of g. Following jensen 2003, the f ratio of g factor eigenvalues low abilityhigh ability was used to test for group differences in g variance. Jan 07, 2018 the g factor is only the latest of the many publications that resulted from what can now be seen as a watershed event. The only exception is when one uses orthogonal rotation which precludes the appearance of a g factor. The abstraction of g stems from the observation that scores on all forms of cognitive tests correlate positively with one another. Africanwhite iq differences from zimbabwe on the wechsler intelligence scale for childrenrevised are mainly on the g factor. The statistical extraction of g is performed by a technique called factor analysis. The book deals with the intellectual history of g and various models of how to conceptualize intelligence, and with the biological correlates of g, its heritability, and its practical predictive power. Spearman reasoned that since the g factor runs through all mental abilities and predicts an individuals performance, it would be of no use to measure specific s factors, since each one.
Jensen the g factor the science of mental ability arthur r. A commentary on interracial peace volume 8 issue 2 panos d. It does not draw back from its most controversial conclusionsthat the average differences in iq found between blacks and whites. Naming it the jensen effect would honor one of the greatest. It is also germane to social issues of national importance. He also contends that g cannot be described in terms of the information content or item characteristics of tests, and likens it to a computers cpu. Personality and individual differences, 26, 3889 proposed that the secular. This explains its great value in predicting job performance. Jensen provides a comprehensive treatment of one of the major constructs of behavioral sciencegeneral mental abilitylabeled the g factor by its discoverer, charles spearman. Gottfredson n the world of the american public school, few subjects are more controversial than intelligence. Nov 15, 2005 however, factor v leiden has been associated with increased morbidity in childhood meningococcal disease. Jensen argues that g is normally distributed in any population.
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