Twin Studies of Behavior

New and Old Findings
  • Thomas J. BouchardJr


In the age of molecular genetics some commentators have questioned whether twin studies will continue to be a useful tool for studying genetic influences on behavior. Many of us think the answer is yes (Bouchard & Propping, 1993). Work with monozygotic twins reared apart provides an imperfect, but nevertheless powerful window on the direct influence of genes on whole organisms. Extended behavior genetics designs that include twins also provide important information about more complex modes of inheritance that will be very difficult to implement with molecular techniques (Lykken, McGue, Tellegen, & Bouchard, 1992). In this presentation I will attempt to illustrate these points and bring you up-to-date on new findings and new twists on old findings in the field of behavior genetics. In order to illustrate the breath and implications of these findings, first, I will sample the major human individual differences—psychological interests, mental abilities, personality, social attitudes and psychopathology—and illustrate the breath and magnitude of genetic influence in each of these domains. Secondly, I will illustrate the much less well-known fact that measures of the environment that are often purported to be “causal agents” may also be a manifestation of genetic influences rather than causal agents in their own right.


Intraclass Correlation Stressful Life Event Genetic Influence Twin Study Monozygotic Twin 
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  1. Allport, G. W., Vernon, P. E., & Lindzey, G. (1960). Manual for the study of values (3rd ed.). Boston: Houghton Mifflin.Google Scholar
  2. Arvey, R. D., Bouchard, T. J., Jr., Segal, N. L., & Abraham, L. M. (1989). Job satisfaction: environmental and genetic components. Journal of Applied Psychology, 74, 187–192.CrossRefGoogle Scholar
  3. Arvey, R. D., McCall, B., Bouchard, T. J., Jr., & Taubman, P. (1994). Genetic influence on job satisfaction and work values. Personality and Individual Differences, 17, 21–33.CrossRefGoogle Scholar
  4. Barling, J. (1990). Employment, stress and family functioning. New York: Wiley.Google Scholar
  5. Barrett, G. V., & Depinet, R. L. (1991). A reconsideration of testing for competence rather than for intelligence. American Psychologist, 46(10), 1012–1024.PubMedCrossRefGoogle Scholar
  6. Betsworth, D. G., Bouchard, T. J., Jr., Cooper, C. R., Grotevant, H. D., Hansen, J. C., Scarr, S., & Weinberg, R. A. (1993). Genetic and environmental influences on vocational interests assessed using adoptive and biological families and twins reared apart and together. Journal of Vocational Behavior, 44, 263–278.CrossRefGoogle Scholar
  7. Blau, Z. S. (1981). Back children/White children: Competence, socialization, and social structure. New York: Free Press.Google Scholar
  8. Block, J. H., Block, J., & Gjerde, P. S. (1986). The personality of children prior to divorce: A prospective study. Child Development, 57, 827–840.PubMedCrossRefGoogle Scholar
  9. Bouchard, T. J., Jr. (1982). [Review of Identical twins reared apart: A reanalysis]. Contemporary Psychology, 27, 190–191.Google Scholar
  10. Bouchard, T. J., Jr. (1983). Do environmental similarities explain the similarity in intelligence of identical twins reared apart? Intelligence, 7, 175–184.CrossRefGoogle Scholar
  11. Bouchard, T. J., Jr. (1994). Genes, environment and personality. Science, 264, 1700–1701.PubMedCrossRefGoogle Scholar
  12. Bouchard, T. J., Jr. (1996a). Behavior Genetic Studies of Intelligence, Yesterday and Today: The Long Journey from Plausibility to Proof. In C. N. G. Mascie-Taylor & C. R. Brand (Eds.), Biological and social aspects of intelligence London: Macmillan.Google Scholar
  13. Bouchard, T. J., Jr. (1996b). The genetics of personality. In K. Blum & E. P. Noble (Eds.), Handbook of psychoeurogenetics Boca Raton, FL: CRC Press.Google Scholar
  14. Bouchard, T. J., Jr., Arvey, R. D., Keller, L. M., & Segal, N. L. (1992). Genetic influences on Job Satisfaction: A reply to Cropanzano and James. Journal of Applied Psychology, 77, 89–93.CrossRefGoogle Scholar
  15. Bouchard, T. J., Jr., Lykken, D. T., McGue, M., Segal, N. L., & Tellegen, A. (1990). Sources of human psychological differences: The Minnesota study of twins reared apart. Science, 250, 223–228.PubMedCrossRefGoogle Scholar
  16. Bouchard, T. J., Jr., Lykken, D. T., Tellegen, A. T., & McGue, M. (1996). Genes, drives, environment and experience: EPD theory — Revised. In C. P. Benbow & D. Lubinski (Eds.), Psychometrics and social issues concerning intellectual talent. Baltimore: John Hopkins University Press.Google Scholar
  17. Bouchard, T. J., Jr., & McGue, M. (1981). Familial studies of intelligence: A review. Science, 212, 1055–1059.PubMedCrossRefGoogle Scholar
  18. Bouchard, T. J., Jr., & Propping, P. (Ed.). (1993). Twins as a tool of behavior genetics. Chichester, England: Wiley & Sons, Ltd.Google Scholar
  19. Bouchard, T. J. J. (1996c). IQ similarity in twins reared apart: Findings and response to critics. In R. J. Sternberg & E. L. Grigorenko (Eds.), Intelligence: Heredity and environment (pp. ***-***). New York: Cambridge University Press.Google Scholar
  20. Bouchard, T. J. J. (under review). Exprience producing drive theory: How genes drive exprience and shape personality. Acta Paediatrica, Paper presented as part of the Nobel Symposium on Genetic vs. Environmental Determination of Human Behavior and Health, Stockholm Sweden, January 22–24, 1996.Google Scholar
  21. Brooks-Gunn, J., & Klebanov, P. K. (1996). Ethnic differences in children’s intelligence test scores: Role of economic deprivation, home environment, and maternal characteristics. Child Development, 67, 396–408.PubMedCrossRefGoogle Scholar
  22. Burks, B. S. (1928a). Chapter X. The relative influence of nature and nurture upon mental development: A comparative study of foster parent-offspring child resemblance and true parent-true child resemblance. Yearbook of the National Society for the Study of Education, 27, 219–316.Google Scholar
  23. Burks, B. S. (Ed.). (1928b). Statistical hazards in nature-nurture investigations. Blomington, Il: Public School Publishing Company.Google Scholar
  24. Burks, B. S. (1938). On the relative contributions of nature and nurture to average group differences in intelligence. Proceedings of the National Academy of Sciences, 24, 276–282.CrossRefGoogle Scholar
  25. Buss, D. M. (1993). Strategic individual differences: The evolutionary psychology of selection, evocation, and manipulation. In T. J. Bouchard, Jr. & P. Propping (Eds.), Twins as a tool of behavioral genetics Chichester: Wiley.Google Scholar
  26. Campbell, D. P. (1966). Stability of interests within an occupation over thirty years. Journal of Applied Psychology, 50, 51–56.PubMedCrossRefGoogle Scholar
  27. Campbell, D. P. (1995). The psychological test profiles of Brigadier Generals: Warmongers or decisive warriors? In D. Lubinski & R. V. Dawis (Eds.), Assessing individual differences in human behavior (pp. 145–175). Palo Alto, CA: Davies-Black.Google Scholar
  28. Carnap, R. (1950). Logical foundations of probability. Chicago: University of Chicago Press.Google Scholar
  29. Castell, A. (1935). A college logic. New York: Macmillan.Google Scholar
  30. Cohen, S., Kessler, R. C., & Gordon, L. U. (1995). Measuring stress: A guide for health and social scientists. New York: Oxford University Press.Google Scholar
  31. Cooper, C. L., & Kirkcaldy, B. D. (1994). A model of job stress and physical health: The role of individual differences. Personality and Individual Differences, 16, 653–657.CrossRefGoogle Scholar
  32. Dahlstrom, W. G., Welsh, G. S., & Dahlstrom, L. E. (1975). An MMPI handbook, Volume II: Research Applications. Minneapolis: University of Minnesota Press.Google Scholar
  33. Diener, E., & Diener, C. (1996). Most people are happy. Psychological Science, 7, 181–185.CrossRefGoogle Scholar
  34. DiLalla, D. L., Carey, G., Gottesman, I. I., & Bouchard, T. J., Jr. (in press). Personality indicators of psychopathology via MMPI in twins reared apart. Journal of Abnormal Psychology.Google Scholar
  35. Dorfman, D. D. (1995). Soft Science with a neoconservative agenda. Review of “The Bell Curve.” Contemporary Psychology, 40, 418–421.Google Scholar
  36. Eaves, L. J., Eysenck, H. J., & Martin, N. G. (1989). Genes, culture and personality: An empirical approach. New York: Academic Press.Google Scholar
  37. Fancher, R. E. (1995). The Bell Curve on separated twins. The Alberta Journal of Educational Research, 41, 265–270.Google Scholar
  38. Feather, N. (1978). Family resemblance in conservatism: Are daughters more similar to parents than sons? Journal of Personality, 46, 260–278.CrossRefGoogle Scholar
  39. Finkel, D., Pedersen, N. L., McGue, M., & McClearn, G. E. (1995). Heritability of cognitive abilities in adult twins: Comparison of Minnesota and Swedish Data. Behavior Genetics, 25, 421–431.PubMedCrossRefGoogle Scholar
  40. Freeman, F. N., Holzinger, K. J., & Mitchell, B. C. (1928). The influence of environment on the intelligence, school achievement and conduct of foster children. In G. M. Whipple (Eds.), Nature and nurture: Their influence on intelligence (The 27th yearbook of the National Society for the Study of Education, Pt. 1) Bloomington, Ill: Public School Publishing.Google Scholar
  41. Galton, F. (1869/1914). Hereditary genius: An inquiry into its laws and consequences. London: Macmillan.Google Scholar
  42. Gati, I. (1991). The structure of vocational interests. Psychological Bulletin, 109, 309–324.CrossRefGoogle Scholar
  43. Gibson, J., & Light, P. (1967). Intelligence among university scientists. Nature, ?, 441–443.Google Scholar
  44. Gibson, J. B. (1973). Social mobility and the genetic structure of populations. Journal of Biosocial Science, 5(251–259).PubMedCrossRefGoogle Scholar
  45. Gottfredson, L. S. (1994, Tuesday, December 3, 1994). Mainstream science on intelligence. Wall Street Journal, p.Google Scholar
  46. Hansen, J. C. (1982). Hansen combined form scales for the SII. In Minneapolis: University of Minnesota Center for Interest Measurement Research.Google Scholar
  47. Hansen, J. C., & Campbell, D. P. (1985). Manual for the SVIB-SCII (4th en.). Stanford, CA: Stanford University Press.Google Scholar
  48. Hayes, K. J. (1962). Genes, drives, and intellect. Psychological Reports, 10, 299–342.CrossRefGoogle Scholar
  49. Hayes, W. L. (1973). Statistics for the social sciences (2 ed.). New York: Holt, Rinehart & Winston.Google Scholar
  50. Herrnstein, R. J., & Murray, C. (1994). The bell curve: Intelligence and class structure in American life. New York: Free Press.Google Scholar
  51. Holmes, T. H., & Rahe, R. M. (1967). The social readjustment rating scale. Journal of Psychosomatic Medicine, 11, 213–218.CrossRefGoogle Scholar
  52. Houston, A. C. (Fall 1995), Children in poverty and public policy. Developmental Psychology Newsletter, American Psychological Association, p. 1–8.Google Scholar
  53. Hudgens, R. W. (1974). Personal catastrophe and depression: A consideration of the subject with respect to medically ill adolescents, and a requiem for retrospective life-event studies. In B. S. Dohrenwend & B. P. Dohrenwend (Eds.), Stressful life events: Their nature and effects (pp. 119–134). New York: Wiley.Google Scholar
  54. Jackson, D. J. (1977). Jackson vocational interest survey manual. Port Huron, MI: Research Psychologists Press.Google Scholar
  55. Jensen, A. R. (1969). How much can we boost IQ and scholastic achievement? Harvard Educational Review, 39, 1–123.Google Scholar
  56. Jensen, A. R. (1973). Equating for socioeconomic variables. In A. R. Jensen (Eds.), Educability and group differences New York: Harper and Row.Google Scholar
  57. Juel-Nielsen, N. (1980). Individual and Environment: Monozygotic twins reared apart (revised edition of 1965 monograph). New York: International Universities Press.Google Scholar
  58. Keller, L. M., Arvey, R. D., Bouchard, T. J., Jr., Segal, N. L., & Dawis, R. V. (1992). Work values: Genetic and environmental influences. Journal of Applied Psychology, 77, 79–88.CrossRefGoogle Scholar
  59. Kendler, K. S., Neale, M., Kessler, R., Heath, A., & Eaves, L. (1993). A twin study of recent life events and difficulties. Archives of General Psychiatry, 50, 789–796.PubMedGoogle Scholar
  60. Lewontin, R. C., Rose, S., & Kamin, L. J. (1984). Not in our genes: Biology ideology, and human nature. Pantheon: New York.Google Scholar
  61. Lichtenstein, P., Hersberger, S. L., & Pedersen, N. L. (1995). Dimensions of occupations: Genetic and environmental influences. Journal of Biosocial Science, 27, 193–206.PubMedGoogle Scholar
  62. Lichtenstein, P., & Pedersen, N. L. (1995). Social relationships, stressful life events, and self-reported physical health: Genetic and environmental influences. Psychology and Health, 10, 295–319.Google Scholar
  63. Livesley, W. J., Jang, K. L., Jackson, D. N., & Vernon, P. A. (1993). Genetic and environmental contributions to dimensions of personality disorders. American Journal of Psychiatry, 150, 1826–1831.PubMedGoogle Scholar
  64. Loehlin, J. C. (1992). Genes and environment in personality development. Newbury Park, CA: Sage Publications.Google Scholar
  65. Loehlin, J. C., Horn, J. M., & Willerman, L. (1996). Heredity, environment and IQ in the Texas adoption study. In R. J. Sternberg & E. L. Grigorenko (Eds.), Heredity, environment and intelligence (pp. ***-***). New York: Cambridge University Press.Google Scholar
  66. Lykken, D., & Tellegen, A. (1996). Happiness is a stocastic phenomenon. Psychological Science, 7, 186–189.CrossRefGoogle Scholar
  67. Lykken, D. T., Bouchard, T. J., Jr., McGue, M., & Tellegen, A. (1990). The Minnesota twin family registry: Some initial findings. Acta Geneticae Medicae et Gemellogiae, 39, 35–70.Google Scholar
  68. Lykken, D. T., Bouchard, T. J., Jr., McGue, M., & Tellegen, A. (1993). Heritability of interests: A twin study. Journal of Applied Psychology, 78, 649–661.PubMedCrossRefGoogle Scholar
  69. Lykken, D. T., McGue, M., Tellegen, A., & Bouchard, T. J., Jr. (1992). Emergenesis: Genetic traits that may not run in families. American Psychologist, 47, 1565–1577.PubMedCrossRefGoogle Scholar
  70. Macintosh, N. J. (Ed.). (1995). Cyril Burt: Fraud or framed. Oxford: Oxford University Press.Google Scholar
  71. Martin, N. G., Eaves, L. J., Heath, A. C., Jardine, R., Feingold, L. M., & Eysenck, H. J. (1986). Transmission of social attitudes. Proceedings of the National Academy of Sciences USA, 83, 4364–4368.CrossRefGoogle Scholar
  72. McGue, M., Bouchard, T. J., Jr., Iacono, W. G., & Lykken, D. T. (1993). Behavior genetics of cognitive ability: A life-span perspective. In R. Plomin & G. E. McClearn (Eds.), Nature, nurture and psychology (pp. 59–76). Washington, D. C.: American Psychological Association.CrossRefGoogle Scholar
  73. McGue, M., & Lykken, D. T. (1992). Genetic influence on risk of divorce. PS, 3, 368–372.Google Scholar
  74. Meehl, P. E. (1970). Nuisance variables and the ex post facto design. In M. Radner & S. Winokur (Eds.), Minnesota Studies in the Philosophy of Science IV Minneapolis: University of Minnesota Press.Google Scholar
  75. Moloney, D. P., Bouchard, T. J., Jr., & Segal, N. L. (1991). A genetic and environmental analysis of the vocational interests of monozygotic and dizygotic twins reared apart. Journal of Vocational Behavior, 39, 76–109.CrossRefGoogle Scholar
  76. Moster, M. (1991) Stressful life events: Genetic and environmental components and their relationship to affective symptomatology. Ph.D. Dissertation, University of Minnesota.Google Scholar
  77. Neale, M. C. (1995). MX: Statistical modeling. Richmond, VA: Department of Human Genetics, Box 3 MCV.Google Scholar
  78. Neale, M. C., & Cardon, L. R. (Ed.). (1992). Methodology for genetic studies of twins and families. Dordrecht: Kluwer Academic Publishers.Google Scholar
  79. Neisser, U., Boodoo, G., Bouchard, T. J., Jr., Boykin, A. W., Brody, N., Ceci, S. J., Halpern, D. F., Loehlin, J. C., Perloff, R., Sternberg, R. J., & Urbina, S. (1996). Intelligence: Knowns and unknows. American Psychologist, 51, 77–101.CrossRefGoogle Scholar
  80. Newman, H. H., Freeman, F. N., & Holzinger, K. J. (1937). Twins: A study of heredity and environment. Chicago: University of Chicago Press.Google Scholar
  81. Pearlstone, A., Russell, R. J. H., & Wells, P. A. (1994). A re-examination of the stress/illness relationship: How useful is the concept of stress. Personality and Individual Differences,17, 577–580.CrossRefGoogle Scholar
  82. Pedersen, N., L., Plomin, R., Nesselroade, J. R., & McClearn, G. E. (1992). A quantitative genetic analysis of cognitive abilities during the second half of the life span. Psychological Science, 3, 346–353.CrossRefGoogle Scholar
  83. Plomin, R. (1994a). Genetics and experience: The interplay between nature and nurture. Thousand Oaks, CA: Sage.Google Scholar
  84. Plomin, R. (1994b). The nature of nurture: The environment beyond the family. In R. Plomin (Eds.), Genetics and experience: The interplay between nature and nurture (pp. 82–101). Thousand Oaks: Sage.Google Scholar
  85. Plomin, R., Lichtenstein, P., Pedersen, N. L., McClearn, G. E., & Nesselroade, J. R. (1990). Genetic influences on life events during the last half of the life span. Psychology and Aging, 5, 25–30.PubMedCrossRefGoogle Scholar
  86. Plomin, R., Pedersen, N. L., Lichtenstein, P., & McClearn, G. E. (1994). Variability and stability in cognitive abilities are largely genetic later in life. Behavior Genetics, 24, 207–215.PubMedCrossRefGoogle Scholar
  87. Robinson, J. P., & Shaver, P. R. (1969). Measures of social psychological attitudes. Ann Arbor, MI: Publications Division, Institute for Social Research.Google Scholar
  88. Rohe, D. (1980) Change in vocational interests after disability. Ph.D., Minnesota.Google Scholar
  89. Scarr, S. (1992). Developmental theories for the 1990’s: Development and individual differences. Child Development, 63, 1–19.PubMedCrossRefGoogle Scholar
  90. Scarr, S., & Weinberg, R. A. (1978). The influence of family background on intellectual attainment. American Sociological Review, 43, 674–692.CrossRefGoogle Scholar
  91. Scarr, S., Weinberg, R. A., & Waldman, I. D. (1993). IQ correlations in transracial adoptive families. Intelligence, 17, 541–555.CrossRefGoogle Scholar
  92. Schmidt, F. L., & Hunter, J. E. (1996). Measurement error in psychological research: Lessons from 26 research scenarios. Psychological Methods, 1, 199–223.CrossRefGoogle Scholar
  93. Shaw, M. E., & Wright, J. M. (1967). Scales for the measurement of attitudes. New York: McGraw-Hill.Google Scholar
  94. Shields, J. (1962). Monozygotic twins: Brought up apart and brought up together. London: Oxford University Press.Google Scholar
  95. Snyderman, M., & Rothman, S. (1988). The IQ controversy: The media and public policy. New Brunswick, NJ: Transaction Books.Google Scholar
  96. Staples, B. (1994, Friday, October 28, 1994). The’ scientific’ war on the poor. New York Times: Editorial, p. A18.Google Scholar
  97. Staw, B. M., Bell, N. E., & Clausen, J. A. (1986). The dispositional approach to job attitudes: A lifetime longitudinal test. American Science Quarterly, 31, 56–77.CrossRefGoogle Scholar
  98. Staw, B. M., & Ross, J. (1985). Stability in the midst of change: A dispositional approach to job attitudes. Journal of Applied Psychology, 70, 469–480.CrossRefGoogle Scholar
  99. Taylor, H. F. (1980). The IQ game: A methodological inquiry into the heredity environment controversy. New Brunswick, N. J.: Rutgers University Press.Google Scholar
  100. Tesser, A. (1993). The importance of heritability in psychological research: The case of attitudes. Psychological Review, 100, 129–142.PubMedCrossRefGoogle Scholar
  101. Waller, J. H. (1971). Achievement and social mobility: Relationships among IQ score, education, and occupation in two generations. Social Biology, 18, 252–259.PubMedGoogle Scholar
  102. Waller, N. G., Kojetin, B. A., Bouchard, T. J., Jr., Lykken, D. T., & Tellegen, A. (1990). Genetic and environmental influences on religious interests, attitudes, and values: A study of twins reared apart and together. Psychological Science, 1(2), 1–5.CrossRefGoogle Scholar
  103. Waller, N. G., Lykken, D. T., & Tellegen, A. (1995). Occupational interests, leisure time interests, and personality: Three domains or one? Findings from the Minnesota Twin Registry. In R. Dawis & D. Lubinski (Eds.), Assessing individual differences in human behavior: New concepts, methods, and findings (pp. 233–259). Palo Alto: Davies-Black.Google Scholar
  104. Weiner, H. (1992). Perturbing the organism: The biology of stressful experience. Chicago: University of Chicago Press.Google Scholar
  105. White, R. K. (1982). The relation between socioeconomic status and academic achievement. Psychological Bulletin, 91, 461–481.CrossRefGoogle Scholar
  106. Zahn-Waxler, C. (1995). Introduction to special section: Parental depression and distress: Implications for development infancy, childhood, and adolescence. Developmental Psychology, 31, 347–348.CrossRefGoogle Scholar

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© Kluwer Academic Publishers 1996

Authors and Affiliations

  • Thomas J. BouchardJr
    • 1
  1. 1.Department of Psychology and Institute of Human GeneticsUniversity of MinnesotaMinneapolis

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