Hostname: page-component-8448b6f56d-jr42d Total loading time: 0 Render date: 2024-04-23T14:05:29.045Z Has data issue: false hasContentIssue false

Null Sex Differences in General Intelligence: Evidence from the WAIS-III

Published online by Cambridge University Press:  10 April 2014

Roberto Colom*
Affiliation:
Autonomous University of Madrid
Luis F. García
Affiliation:
Autonomous University of Madrid
Manuel Juan-Espinosa
Affiliation:
Autonomous University of Madrid
Francisco J. Abad
Affiliation:
Autonomous University of Madrid
*
Correspondence concerning this article should be addressed to Roberto Colom, Facultad de Psicología.Universiad Autónoma de Madrid. Ciudad Universitaria de Cantoblanco. 28049 Madrid (Spain). E-mail: roberto.colom@uam.es

Abstract

There is an increasing number of studies claiming that the sex differences in general intelligence are “real.” The empirical evidence is based on the summation of the standardized sex differences in several cognitive batteries. However, the scientific construct of general ability rests on the correlations among test scores, rather than on their summation. The latter (ability in general) is an arbitrary variable, not a scientific construct. General ability is not a function of any particular cognitive test, but a source of variance evidenced by the correlation between several diverse tests, each of which reflects general ability (g) to some extent, but also group factors and test specificity. Because there are important educational, economic, and social consequences of a group difference in general ability, it is especially germane to evaluate the possibility of an average sex difference in its proxy measures, such as IQ. The Spanish standardization of the WAIS-III is analyzed in the present study. The sample was made up of 703 females and 666 males, aged 15-94, drawn as a representative sample of the population in terms of educational level and geographical location. Although a male advantage of 3.6 IQ points is observed, the difference is in “ability in general,” not in “general ability” (g). Given that the main ingredient of the strong association between IQ and a broad range of social correlates is g, and given that there is no sex difference in g, then the average IQ sex-difference favoring males must be attributed to specific group factors and test specificity.

Un número creciente de estudios sostiene que “existen” diferencias entre los sexos en inteligencia general. Las pruebas empíricas se basan en la suma de las diferencias estandarizadas entre los sexos en diversas baterías cognitivas. Sin embargo, el constructo científico de inteligencia general se basa en la correlación entre las puntuaciones obtenidas en los tests, no en su suma. La suma de puntuaciones (inteligencia en general) constituye una variable arbitraria, no un constructo científico. La inteligencia general no es función de un determinado test, sino que constituye una fuente de varianza puesta de manifiesto por la correlación entre diversos tests, cada uno de los cuales refleja inteligencia general (g), factores de grupo y especificidad del propio test. Puesto que existen importantes consecuencias educativas, económicas y sociales de las diferencias de grupo en inteligencia general, resulta especialmente pertinente valorar la posibilidad de que exista una diferencia promedio entre sexos en medidas como el CI. En este estudio se emplea la adaptación española del WAIS-III. La muestra está formada por 703 mujeres y 666 varones de entre 15 y 94 años de edad, representativa de la población en nivel educativo y localización geográfica. Aunque se observa una ventaja promedio de los varones de 3.6 puntos de CI, la diferencia se debe a la “inteligencia en general”, no a la “inteligencia general” (g). Dado que el principal ingrediente de la fuerte asociación que existe entre el CI y un amplio conjunto de correlatos sociales es g, y que no existe una diferencia según el sexo en g, entonces la diferencia promedio de CI que favorece a los varones debe atribuirse a los factores de grupo y a la especificidad de los tests.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2002

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Aluja, A., Colom, R., Abad, F.J., & Juan-Espinosa, M. (2000). Sex differences in general intelligence defined as g among young adolescents. Personality and Individual Differences, 28, 813820.CrossRefGoogle Scholar
Ankey, C. (1992). Sex differences in relative brain size: The mismeasure of woman, too? Intelligence, 16, 329336.Google Scholar
Ankey, C. (1995). Sex differences in brain size and mental abilities: Comments on R. Lynn and D. Kimura. Personality and Individual Differences, 18, 423424.CrossRefGoogle Scholar
Brody, N. (1992). Intelligence (2nd ed.). San Diego, CA: Academic Press.Google Scholar
Carroll, J.B. (1993). Human cognitive abilities. A survey of factor analytic studies. Cambridge, MA: Cambridge University Press.CrossRefGoogle Scholar
Carroll, J.B. (1997). Psychometrics, intelligence, and public perception. Intelligence, 24, 2552.CrossRefGoogle Scholar
Cattell, R.B. (1978). The scientific use of factor analysis. New York: Plenum.CrossRefGoogle Scholar
Colom, R. (1998). Psicología de las diferencias individuales. Teoría y práctica. Madrid: Pirámide.Google Scholar
Colom, R., Juan-Espinosa, M., Abad, F.J., & García, L.F. (2000). Negligible sex differences in general intelligence. Intelligence, 28, 5768.CrossRefGoogle Scholar
Gordon, R.A. (1997). Everyday life as an intelligence test: Effects of intelligence and intelligence context. Intelligence, 24, 203320.CrossRefGoogle Scholar
Gottfredson, L. (Ed.) (1986). The g factor in employment [Special Issue]. Journal of Vocational Behavior, 29 (3).CrossRefGoogle Scholar
Gottfredson, L. (1997a). Why g matters: The complexity of everyday life. Intelligence, 24, 79132.CrossRefGoogle Scholar
Gottfredson, L. (1997b). Foreword to “Intelligence and Social Policy.” Intelligence, 24, 112.CrossRefGoogle Scholar
Halpern, D. (1992). Sex differences in cognitive abilities. Hillsdale, NJ: Erlbaum.Google Scholar
Hattori, K., & Lynn, R. (1997). Male-female differences on the Japanese WAIS-R. Personality and Individual Differences, 23, 531533.Google Scholar
Herrnstein, R., & Murray, Ch. (1994). The bell curve. Intelligence and class structure in American life. New York: Free Press.Google Scholar
Hunt, E. (1995). Will be we smart enough? A cognitive analysis of the coming workforce. New York: Russell Sage Foundation.Google Scholar
Hunter, J.E. (1983). Overview of validity generalization for the U.S. Employment Service (USES Test Research Report N° 43). Washington, DC: U.S. Department of Labor, Employment and Training Administration.Google Scholar
Hunter, J.E. (1986). Cognitive ability, cognitive aptitudes, job knowledge, and job performance. Journal of Vocational Behavior, 29, 340362.CrossRefGoogle Scholar
Hunter, J.E., & Hunter, R.F. (1984). Validity and utility of alternative predictors of job performance. Psychological Bulletin, 96, 7298.CrossRefGoogle Scholar
Hunter, J., & Schmidt, F. (1990). Methods of meta-analysis: Correcting error and bias in research finding. Newbury Park, CA: Sage.Google Scholar
Jensen, A. (1980). Bias in mental testing. London: Methuen.Google Scholar
Jensen, A. (1992). Vehicles of g. Psychological Science, 3, 275277.CrossRefGoogle Scholar
Jensen, A. (1998). The g factor. London: Praeger.Google Scholar
Juan-Espinosa, M. (1997). Geografía de la inteligencia humana. Madrid: Pirámide.Google Scholar
Loehlin, J.C. (1992). Latent variable models: An introduction to factor, path, and structural analysis (2nd ed.). Hillsdale, NJ: Erlbaum.Google Scholar
Lynn, R. (1994). Sex differences in intelligence and brain size: A paradox resolved. Personality and Individual Differences, 17, 257271.CrossRefGoogle Scholar
Lynn, R. (1998). Sex differences in intelligence: Data from a Scottish standardization of the WAIS-R. Personality and Individual Differences, 24, 289290.CrossRefGoogle Scholar
Lynn, R. (1999). Sex differences in intelligence and brain size: A developmental theory. Intelligence, 27, 112.CrossRefGoogle Scholar
Mackintosh, N.J. (1998). IQ and human intelligence. Oxford, UK: Oxford University Press.Google Scholar
McHenry, J.J., Hough, L.M., Toquam, J.L., Hanson, M.A., & Ashworth, S. (1990). Project A validity results: The relationship between predictor and criterion domains. Personnel Psychology, 43, 335354.CrossRefGoogle Scholar
Neisser, U., Boodoo, G., Bouchard, T., Boykin, A., Brody, N., Ceci, S., Halpern, D., Loehlin, J., Perloff, R., Sternberg, R., & Urbina, S. (1996). Intelligence: Knowns and unkowns. American Psychologist, 51, 77101.CrossRefGoogle Scholar
Ree, M.J., & Earles, J.A. (1991). Predicting training success: Not much more than g. Personnel Psychology, 44, 321332.CrossRefGoogle Scholar
Rushton, J.P. (1992). Cranial capacity related to sex, rank, and race in a stratified sample of 6,325 U.S. military personnel. Intelligence, 16, 401414.CrossRefGoogle Scholar
Rushton, J.P. & Ankey, C.D. (1996). Brain size and cognitive ability: Correlations with age, sex, social class, and race. Psychonomic Bulletin and Review, 3, 2136.CrossRefGoogle ScholarPubMed
Schmidt, F.L., Hunter, J.E., Outerbridge, A.N., & Goff, S. (1988). Joint relation of experience and ability with job performance: Test of three hypotheses. Journal of Applied Psychology, 73, 4657.CrossRefGoogle Scholar
Schmid, J., & Leiman, J.M. (1957). The development of hierarchical factor solutions. Psychometrika, 22, 5361.CrossRefGoogle Scholar
Wechsler, D. (1997). Wechsler Adult Intelligence Scale (3rd ed.). San Antonio, TX: The Psychological Corporation. (Spanish adaptation: WAIS-III: Escala Wechsler para adultos. Madrid: TEA, 1998).Google Scholar