Human Nature

, Volume 8, Issue 2, pp 139–151 | Cite as

Matrilateral biases in the investment of aunts and uncles

A consequence and measure of paternity uncertainty
  • Steven J. C. GaulinEmail author
  • Donald H. McBurney
  • Stephanie L. Brakeman-Wartell


In a study of the kin investment of aunts and uncles we show that the laterality effect expected as a result of paternity uncertainty is statistically reliable but somewhat smaller than the sex effect. Matrilateral aunts invest significantly more than patrilateral aunts, and the same is true for uncles. Regardless of laterality, however, aunts invest significantly more than uncles. Multivariate controls show that the matrilateral bias is fully independent of any age or distance confounds that might result from sex differences in age at marriage or dispersal. We discuss our results in relation to recent findings on the kin investment of grandparents (Euler and Weitzel 1996). In addition, we propose a simple method for estimating the level of paternity uncertainty from kin investment data; application of this method to our data on aunts and uncles suggests that between 13% and 20% of children are not the offspring of their putative father. Our parallel analyses of Euler and Weitzel’s (1996) data on grandparental investment suggest a similar estimate, that paternity uncertainty lies between 9% and 17%.

Key words

Kin investment Matrilateral bias Paternity uncertainty 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Alexander, R. D. 1979 Darwinism and Human Affairs. Seattle: University of Washington Press.Google Scholar
  2. Baker, R. R., and M. A. Bellis 1995 Human Sperm Competition. London: Chapman and Hall.Google Scholar
  3. Christenfeld, N. J. S., and E. A. Hill 1995 Whose Baby Are You? Nature 378:669.CrossRefGoogle Scholar
  4. Daly, M., and M. Wilson 1982 Whom Are Newborn Babies Said to Resemble? Ethology and Sociobiology 3:69–78.CrossRefGoogle Scholar
  5. Euler, H., and B. Weitzel 1996 Discriminative Grandparental Solicitude as Reproductive Strategy. Human Nature 7:39–59.Google Scholar
  6. Hartung, J. 1985 Matrilineal Inheritance: New Theory and Analysis. The Behavioral and Brain Sciences 8:661–688.CrossRefGoogle Scholar
  7. Hawkes, K., A. R. Rogers, and E. L. Charnov 1995 The Male’s Dilemma: Increased Offspring Production Is More Paternity to Steal. Evolutionary Ecology 9:662–677.CrossRefGoogle Scholar
  8. Hrdy, S. 1980 The Langurs of Abu: Female and Male Strategies of Reproduction. Cambridge MA: Harvard University Press.Google Scholar
  9. Kurland, J. A. 1979 Paternity, Mother’s Brother and Human Sociality. In Evolutionary Biology and Human Social Behavior, N. A. Chagnon and W. Irons, eds. Pp. 145–180. North Scituate, Massachusetts: Duxbury Press.Google Scholar
  10. Nesse, R. M, A. Silverman, and A. Bortz 1990 Sex differences in ability to recognize family resemblance. Ethology and Sociobiology 11:12–21.CrossRefGoogle Scholar
  11. Regalski, J. M., and S. J. C. Gaulin 1993 Whom Are Mexican Infants Said to Resemble? Monitoring and Fostering Paternal Confidence in the Yucatan. Ethology and Sociobiology 14:97–113.CrossRefGoogle Scholar

Copyright information

© Walter de Gruyter, Inc 1997

Authors and Affiliations

  • Steven J. C. Gaulin
    • 1
    Email author
  • Donald H. McBurney
    • 1
  • Stephanie L. Brakeman-Wartell
    • 1
  1. 1.Department of AnthropologyUniversity of PittsburghPittsburgh

Personalised recommendations