Alloparenting and Child Health Outcomes among the Comca'ac

Abstract

Alloparenting has played a pivotal role in every society throughout human history in ensuring the survival and healthy development of children. A large amount of theory (e.g. kin-selection) and evidence exists to support this claim, and though alloparenting is certainly not unique to humans, it is difficult to suggest that any other species benefits from it more, and certainly not one as ubiquitous as Homo sapiens. However, there is a surprising dearth of empirical research examining the causes of individual variation in the amount and type of alloparental behavior that a child receives, and what effect this variation has on previously validated measures of child well-being. We propose how different measures of familial relatedness and the spatial distribution of relatives might be used to predict the amount and type of alloparental care a child receives, and how these variables may interact to affect a child’s health. We employed a variety of different methods; genealogical modeling, genetic analysis, geospatial mapping, ethological behavioral observations, and anthropometric measurements in order to generate objective data to test these predictions. As members of a relatively isolated native people in Sonora, Mexico, our study population (the Comca'ac) is uniquely suited to help us test our hypotheses. From just this pilot study, we have made many methodological developments and found strong support for many of our hypotheses. There are many new questions to answer as well, which together suggest the future directions for an intensive study of a broader sample of this population, and alloparental behavior in humans in general.