Behavior Genetics

, Volume 26, Issue 2, pp 123–133

Social contact, social attitudes, and twin similarity

  • Samuel F. Posner
  • Laura Baker
  • Andrew Heath
  • Nicholas G. Martin


The nature of the relationship between social contact and attitude similarity between twins was investigated using longitudinal data from a sample of Australian twins. Earlier research has suggested that social attitudes are not explained solely by shared environment; rather there are both genetic and environmental components that explain variance in social attitudes. Using three types of analyses we investigated the magnitude of the relationship and the direction of causation between attitude similarity and social contact. Longitudinal analysis of within-pair variance by level of contact suggests that attitude similarity leads to contact among the females and that similarity is both genetically and environmentally based. Analyses using a crosslag regression model suggest that similarity causes contact among MZ females. Biometrical analyses indicate differences in direction of causation for males and females. Among females, both genetic and shared environmental parameter estimates could be equated across contact groups, suggesting little relationship between contact and similarity. Among males, findings of smaller estimated heritability in the high-contact group suggest that similarity causes contact. However, an increased estimate of the contribution of shared environmental variance in the high-contact males could additionally suggest that contact leads to similarity.

Key Words

Attitudes contact twin similarity 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Akaike, H. (1970). Statistical predictor identification.Ann. Stat. Math. 21:243–247.Google Scholar
  2. Cederlof, R., Friberg, L., Jonsson, E., and Kaij, L. (1961). Studies on similarity diagnosis in twins with the aid of mailed questionnaires.Acta Genet. Stat. Med. 11:338–362.PubMedGoogle Scholar
  3. Eaves, L. J., Eysenck, H. J., and Martin, N. G. (1989).Genes, Culture and Personality, Harcourt Brace Jovanovich, London.Google Scholar
  4. Falconer, D. S. (1989).Introduction to Quantitative Genetics, John Wiley & Sons, New York.Google Scholar
  5. Heath, A. C., and Eaves, L. J., (1985). Resolving the effects of phenotypic and social, background on mate selection.Behav. Genet. 15(1):15–30.CrossRefPubMedGoogle Scholar
  6. Heath, A. C., Cloninger, R. C., and Martin, N. G. (1994). Testing a model for the genetic structure of personality: A comparison of the personality systems of Cloninger and Eysenck.J. Personal. Soc. Psychol. 66(4):762–775.Google Scholar
  7. Kasriel, J., and Eaves, L. J. (1976). A comparison of the accuracy of written questionnaires with blood-typing for diagnosing zygosity in twins.J. Biosoc. Sci. 8:263–226.PubMedGoogle Scholar
  8. Lykken, D. T., McGue, M., Bouchard, T. J., and Tellegen, A. (1990). Does contact lead to similarity or similarity to contact?Behav. Genet. 20(5):547–561.CrossRefPubMedGoogle Scholar
  9. Magnus, P., Berg, K., and Nancy, W. E. (1983). Predicting zygosity in Norwegian twins pairs born 1915–1960.Clin. Genet. 24:103–112.PubMedGoogle Scholar
  10. Martin, N. G., and Martin, P. G., (1975). The inheritance of scholastic abilities in a sample of twins. I. Ascertainment of the sample and diagnosis of zygosity.Ann. Hum. Genet. 39:213–218.PubMedGoogle Scholar
  11. Martin, N. G., Eaves, L. J., Heath, A. C., Jardine, R., Feingold, L. M., and Eysenck, H. J. (1986). Transmission of social attitudes.Proc. Nat. Acad. Sci. 83:4364–4368.PubMedGoogle Scholar
  12. Morris-Yates, A., Andrews, G., Howie, P., and Henderson, S. (1990). Twins: A test of the equal environments assumption.Acta Psychiat. Scand. 81:322–326.PubMedGoogle Scholar
  13. Neale, M. (1991).MX: Statistical Modeling, Department of Human Genetics, Medical College of Virginia, Virginia Commonwealth University, Richmond.Google Scholar
  14. Ooki, S., Yamada, K., Asaka, A., and Hayakawa, K. (1990). Zygosity diagnosis of twins by questionnaire.Acta Genet. Med. Gemellol. (Roma) 39:109–115.Google Scholar
  15. Rose, R., Kaprio, J., Williams, C., Viken, R., and Obremski, K. (1990). Social contact and sibling similarity: Facts, issues and red herrings.Behav. Genet. 20(6):763–778.CrossRefPubMedGoogle Scholar
  16. Truett, K. R., Eaves, L. J., Meyer, J. M., Heath, A. C., and Martin, N. G. (1992). Religion and education as mediators of attitudes: A multivariate analysis.Behav. Genet. 22(1): 43–62.CrossRefPubMedGoogle Scholar
  17. Wilson, G. D., and Patterson, J. R. (1968). A new measure of conservatism.Brit. J. Soc. andClinical Psychology 7:264–269.Google Scholar

Copyright information

© Plenum Publishing Corporation 1996

Authors and Affiliations

  • Samuel F. Posner
    • 1
  • Laura Baker
    • 1
  • Andrew Heath
    • 2
  • Nicholas G. Martin
    • 3
  1. 1.Medical Effectiveness Research CenterUniversity of California, San FranciscoSan Francisco
  2. 2.Department of PsychiatryWashington University School of MedicineSt. Louis
  3. 3.Queensland Institute of Medical ResearchBrisbaneAustralia

Personalised recommendations