Parent-Offspring Conflict: Reproductive Effort of Karo Batak Mothers in Rural North Sumatra

Geoffrey C Kushnick, University of Washington

Parental investment theory is a robust framework for explaining variation amongst individuals in parenting and fertility, and other types of reproductive effort. Despite this, its parental-optimum modeling approach may fall short of predicting outcomes when the inclusive fitness interests of parents and their offspring diverge, and offspring have a means for demanding resources in excess of those their parents are willing to give. Here, I test hypotheses based on parent-offspring conflict theory with data on inter-birth intervals, breastfeeding, and household economy collected in 2003-2004 amongst a stratified-random sample of 240 Karo Batak women from 2 highland villages in North Sumatra, Indonesia. This study is part of a larger project that assesses the power of this model for explaining human reproductive effort and offspring outcomes, and has implications for meshing theory and methods in demography, anthropology, and biology.