Hostname: page-component-78c5997874-j824f Total loading time: 0 Render date: 2024-11-07T21:29:42.575Z Has data issue: false hasContentIssue false

School Achievement, Intelligence, and Personality in Twins

Published online by Cambridge University Press:  01 August 2014

B.T. Telles da Silva
Affiliation:
Department of Genetics, Institute of Biosciences, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
M.R.L. Borges Osorio
Affiliation:
Department of Genetics, Institute of Biosciences, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
F.M. Salzano*
Affiliation:
Department of Genetics, Institute of Biosciences, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
*
Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Caixa Postal 1953, 90000 Porto Alegre, RS, Brazil

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

A sample of 47 MZ and 49 DZ pairs of Brazilian twins was investigated in relation to school achievement in six specific areas of study, as well as performance in the test of Dominoes, the Differential Aptitude Tests (DAT) and Griéger's Characterological Questionnaire. Significant F-ratios (variance within DZ/variance within MZ) were observed for the school grades obtained in five of the six areas considered, as well as for their general average; the same being true for the results on the indicated measure of general intelligence, six of the eight DAT tests, and two of the characterological elements. There is a clear positive relationship between the grades earned by the twins and their performance in the Dominoes test. Achievement in Portuguese and foreign language correlates positively with DAT's Sentences; and achievement in mathematics correlates positively with DAT's Numerical Ability, Abstract Reasoning, and Clerical Speed and Accuracy. The results show an agreement with previous estimates of the genetic determination of these variables, which is to a certain extent surprising if we consider the differences in sample sizes, age, and degree of schooling of the subjects, environmental differences, and the dissimilarities which exist between the homes and school systems of USA, Europe, and Brazil.

Riassunto

RIASSUNTO

È stato studiato un campione di 47 coppie MZ e 49 DZ di gemelli brasiliani in rapporto al rendimento scolastico in sei specifiche aree di studio, cosí come in rapporto al rendimento in un certo numero di test di intelligenza e personalità. Sono stati osservati dei valori significativi di F (rapporto fra varianza nei DZ e varianza nei MZ) nei voti ottenuti in 5 delle 6 aree considerate, come pure nella media generale. Lo stesso vale per la misura dell'intelligenza generale. I risultati concordano con le precedenti stime della determinazione genetica di queste variabili, il che è in certa misura sorprendente quando si considerino le differenze per dimensioni del campione, età e grado di scolarità dei soggetti, differenze ambientali, nonché le differenze esistenti nei sistemi scolastici negli Stati Uniti, in Europa e in Brasile.

Résumé

RÉSUMÉ

Un échantillon de 47 couples MZ et 49 couples DZ de jumeaux brésiliens a été étudié par rapport aux résultats scolaires dans six domaines spécifiques, ainsi que par rapport aux résultats dans un certain nombre de tests d'intelligence et de personnalité. Des valeurs significatives de F (rapport entre variance chez les DZ et variance chez les MZ) ont été observées dans cinq des six domaines d'étude considérés, ainsi que dans l'évaluation de l'intelligence générale. Les résultats sont en accord avec les évaluations précédentes de la détermination génétique de ces variables. Ceci est surprenant si l'on considère les différences par rapport aux dimensions de l'échantillon, l'âge et le niveau scolaire des sujets, les différences de milieu, ainsi que les différences qui existent dans les systèmes scolaires aux Etats Unis, en Europe et au Brésil.

Zusammenfassung

ZUSAMMENFASSUNG

Bei einer Reihe brasilianischer Zwillingspaare (47 EZ und 49 ZZ) wurden die Schulleistungen auf sechs spezifischen Fachgebieten sowie die Ergebnisse einer Reihe von Intelligenz- und Persönlichkeitstests untersucht. Bei 5 der 6 untersuchten Fachgebiete sowie in den allgemeinen Durchschnittsleistungen konnten bemerkenswerte Resultate für F (Verhältnis zwischen der Varianz bei ZZ und der bei EZ) beobachtet werden. Das gleiche gilt für die Messung der allgemeinen Intelligenz. Die Ergebnisse stimmen mit vorhergegangenen Schätzungen der Erbbendingtheit dieser Variablen überein. Dies verwundert etwas, wenn man die Unterschiede bedenkt, die einerseits im Ausmass der Versuchsreihe, im Alter und im Schultyp der Kandidaten, andererseits in den Umweltsbedingungen sowie im Schulsystem zwischen USA, Europa und Brasilien bestehen.

Type
Research Article
Copyright
Copyright © The International Society for Twin Studies 1975

References

REFERENCES

Anstey, E. 1967. Teste de Dominos. Buenos Aires: Ed. Paidós.Google Scholar
Bennett, G.K., Seashore, H.G., Wesman, A.G. 1959. Manual do D.A.T. Rio de Janeiro: Centro Editor de Psicologia Aplicada.Google Scholar
Bock, R.D., Vandenberg, S.G. 1968. Components of heritable variation in mental test scores. In Vandenberg, S.G. (ed.): Progress in Human Behavior Genetics [pp. 233260]. Baltimore: The Johns Hopkins Press.Google Scholar
Breland, N.S., Nichols, R.C. 1973. Genetic and environmental components of human trait variation as determined by twin studies. (Manuscript).Google Scholar
Burt, C. 1958. The inheritance of mental ability. Am. Psychol., 13: 115.CrossRefGoogle Scholar
Burt, C. 1966. The genetic determination of differences in intelligence: a study of monozygotic twins reared together and apart. Br. J. Psychol., 57: 137153.Google Scholar
Callegari, S.M., Salzano, F.M., Peña, H.F. 1972 a. ABO saliva and plasma agglutinins in twins. Acta Genet. Med. Gemellol. (Roma), 21: 287296.CrossRefGoogle ScholarPubMed
Callegari, S.M., Salzano, F.M., Peña, H.F. 1972 b. ABH salivary secretion in twins. Acta Genet. Med. Gemellol. (Roma), 21: 297304.CrossRefGoogle ScholarPubMed
Cavalli-Sforza, L.L., Bodmer, W.F. 1971. The Genetics of Human Populations. San Francisco: W.H. Freeman.Google Scholar
Da Rocha, F.J., Salzano, F.M., Peña, H.F., Callegari, S.M. 1972. New studies on the heritability of anthropometric characteriastics as ascertained from twins. Acta Genet. Med. Gemellol. (Roma), 21: 125134.CrossRefGoogle Scholar
Erlenmeyer-Kimling, L., Jarvik, L.F. 1963. Genetics and intelligence: a review. Science, 142:14771479.Google Scholar
Eysenck, H.J. 1953. The Structure of Human Personality. London: Methuen.Google Scholar
Griéger, P. 1952. Le Diagnostic Caractérologique. Paris: Ed. Ligel.Google Scholar
Holzinger, K.J. 1929. The relative effect of nature and nurture influences on twin differences. J. Educat. Psychol., 20: 245248.CrossRefGoogle Scholar
Husén, T. 1959. Psychological Twin Research. A Methodological Study. Stockholm: Almqvist and Wiksell.Google Scholar
Layzer, D. 1974. Heritability analyses of IQ scores: science or numerology? Science, 183: 12591266.CrossRefGoogle ScholarPubMed
Maynard-Smith, S., Penrose, L.S., Smith, C.A.B. 1961. Mathematical Tables for Research Workers in Human Genetics. London: J.A. Churchill.Google Scholar
Newman, H.H., Freeman, F.N., Holzinger, K.J. 1937. Twins: A Study of Heredity and Environment. Chicago: University of Chicago Press.Google Scholar
Nichols, R.C. 1965. The inheritance of general and specific ability. National Merit Scholarship Corporation Research Reports, 1: 116.Google Scholar
Peña, H.F., Salzano, F.M., Callegari, S.M. 1973. Dermatoglyphics in twins. Acta Genet. Med. Gemellol. (Roma), 22: 9198.CrossRefGoogle ScholarPubMed
Shields, J. 1962. Monozygotic Twins Brought up Apart and Brought up Together. Oxford: Oxford University Press.Google Scholar
Stocks, P., Karn, M.N. 1933. A biometric investigation of twins and their brothers and sisters. Ann. Eugen., 5: 155.CrossRefGoogle Scholar
Thorndike, E.L. 1905. The Measurement of Twins. New York: Science Press.Google Scholar
Vandeberg, S.G. 1967 a. Hereditary factors in normal personality traits (as measured by inventories). In Wortis, J. (ed.). Recent Advances in Biological Psychiatry [Vol. 9, pp. 65104]. New York: Plenum Press.CrossRefGoogle Scholar
Vandenberg, S.G. 1967 b. Hereditary factors in psychological variables in man, with a special emphasis on cognition. In Spuhler, J.N. (ed.). Genetic Diversity and Human Behavior [pp. 99133]. Chicago: Aldine.Google Scholar
Vandenberg, S.G. 1969. Human behavior genetics: present status and suggestions for future research. Merrill-Palmer Quart. Behav. Developm., 15: 121154.Google Scholar