Behavior Genetics

, Volume 6, Issue 1, pp 17–30 | Cite as

Heritability of personality traits in adult male twins

  • Joseph M. Horn
  • Robert Plomin
  • Ray Rosenman


Personality test data from the California Psychological Inventory were collected on 99 pairs of identical and 99 pairs of fraternal adult male twins. Heritabilities were computed for all 18 scales and compared to the heritabilities for “pure” scales with overlapping items omitted. Two of the pure scales. Responsibility and Femininity, had zero heritabilities, whereas all of the full scales had moderate to high heritabilities. It was concluded that item overlap has contributed significantly to previous failures to find evidence for the differential heritability of personality traits as measured by the CPI. CPI items were classified into genetic or environmental categories and separate factor analyses of items in these categories revealed more differences than similarities in factor structure. The genetic personality factors included Conversational Poise, Compulsiveness, and Social Ease. Environmental factors included Confidence in Leadership, Impulse Control, Philosophical Attitudes, Intellectual Interest, and Exhibitionism. Compared to the genetic factors, each of the environmental factors accounted for only a very small percentage of the variance.

Key Words

CPI twins heritability genetic factors 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Bruun, K. T., Markanen, T., and Partanen, J. (1966).Inheritance of Drinking Behavior: A Study of Adult Twins mFinnish Foundation for Alcohol Research, Helsinki.Google Scholar
  2. Falconer, D. S. (1960).Introduction to Quantitative Genetics. Oliver and Boyd, London.Google Scholar
  3. Goldberg, I. R., and Rorer, I. G. (1964). Test Retest Item Statistics for the California Psychological Inventory. Oregon Research Institute Monograph, Vol. 4. No. 1.Google Scholar
  4. Gottesman, I. I. (1965). Personality and natural selection. In Vandenberg, S. (ed.),Methods and goals in Human Behavior Genetics, Academic Press, New York.Google Scholar
  5. Gottesman, I. I. (1966). Genetic variance in adaptive personality traits.J. Child Psychol. Psychiat. 7:199–208.Google Scholar
  6. Gough, H. (1969).Manual for the California Psychological Inventory, rev. ed., Consulting Psychologists Press, Palo Alto, Calif.Google Scholar
  7. Jablon, S., Neel, J. V., Gershowitz, H., and Atkinson, G. F. (1967). The NRS-NRC twinpanel: The panel, zygosity diagnosis, and proposed use.Am. J. Hum. Genet. 19:145–160.Google Scholar
  8. Klein, T. W., DeFries, J. C., and Finkbeiner, C. T. (1973). Heritability and genetic correlation: Standard errors of estimates and sample size.Behav. Genet. 3:355–364.Google Scholar
  9. Lochlin, J. (1965). A heredity environment analysis of personality inventory data. In Vandenberg, S. (ed.),Methods and Goals in Human Behavior Genetics. Academic Press, New York.Google Scholar
  10. Nichols, R. C. (1966). The resemblance of twins in personality and interests.National Merit Scholarship Corp. Res. Rep. 2:1–23.Google Scholar
  11. Nichols, R. C., and Schnell, R. R. (1963). Factor scales for the California Psychological Inventory.J. Consult. Psychol. 27:228–235.Google Scholar
  12. Nie, N. H., Bent, D. H., and Huss, C. H. (1970).Statistical Package for the Social Sciences, McGraw-Hill, New York.Google Scholar
  13. Plomin, R., Willerman, L., and Loehlin, J. C. (1976). Resemblance in appearance and the equal environments assumption in twin studies of personality traits.Behav. Genet. 6:43–52.Google Scholar
  14. Scarr, S. (1969). Social introversion extraversion as a heritable response.Child Develop. 40:823–832.Google Scholar
  15. Schoenfeldt, L. F. (1968). Hereditary environmental components of the Project Talent twoday battery. Paper read at XVIth Congress of Applied Psychology, Amsterdam, August 22.Google Scholar
  16. Vandenberg, S. G. (1962). The hereditary abilities study: Hereditary components in a psychological test battery.Am. J. Hum. Genet. 19:220–237.Google Scholar

Copyright information

© Plenum Publishing Corporation 1976

Authors and Affiliations

  • Joseph M. Horn
    • 1
  • Robert Plomin
    • 1
  • Ray Rosenman
    • 2
  1. 1.University of Texas at AustinAustin
  2. 2.Mount Zion Hospital and Medical CenterSan Francisco

Personalised recommendations