Behavioral Ecology and Sociobiology

, Volume 38, Issue 2, pp 75–81

Biased parental investment and reproductive success in Gabbra pastoralists

  • Ruth Mace

DOI: 10.1007/s002650050219

Cite this article as:
Mace, R. Behav Ecol Sociobiol (1996) 38: 75. doi:10.1007/s002650050219


Demographic data from 848 Gabbra households are used to examine the relationships between herd size and reproductive success in relation to sex, in a traditional, pastoralist population. The number of camels in the household herd has a significant positive effect on the reproductive success of both men and women, although the effect of wealth is greater for men, as predicted from evolutionary theory. The greater the number of elder brothers a man has, the lower his reproductive success, as a result of a smaller initial herd and a later age at marriage. This is not true for women –number of elder sisters does not have a measurable effect on a woman’s fertility, although it does have a small, negative effect on the size of her dowry. These results are interpreted as competition between same-sex siblings for parental investment, in the form of their father’s herd, which is more intense between sons than daughters as parental investments are greatest in males.

Key words GabbraWealthReproductive successBirth orderParental investment

Copyright information

© Springer-Verlag Berlin Heidelberg 1996

Authors and Affiliations

  • Ruth Mace
    • 1
  1. 1.Department of Anthropology, University College London, London WC1E 6BT, UKGB