Evolutionary History of Hunter-Gatherer Marriage Practices

Robert Walker’s article starts out “Marriage is a human universal that unites males and females in socially recognized reproductive units.” Marriage goes beyond reproductive significance as a principle form of economic, social and kinship ties. By framing marriage in this manner he hopes to figure out if reciprocal marriage is the original form of marriage, or whether it is a more recent phenomenon

In a comparative study of 190 hunter-gatherer socities, 85% had arranged marriages. 80% of the total sample employed a bride price, and less than 17% of marriages are polygynous. The common forms of marriage across hunter-gatherer cultures suggests an underlying structure for marriage.

Combining mitochondrial genetics and phylogenic reconstructions show interesting relationships about the evolution of marriage. There are low levels of polygyny in early humans, with the exception of Australian aborigines. The practice of brideprice seems to be a common state for all early humans. Determining the role of courtship versus arranged marriages is more difficult to determine. Three of four African hunter-gatherer groups employ courtship rituals, making ancestral determination a mix of both.

Statistical associations between types of marriages indicate that polygyny is more likely to occur in larger families when the kin, and not the parents, arrange the marriages. When hunter-gatherers with arranged marriages are related the ecological variables used by Binford to construct his hunter gatherer database, no associations can be seen. It more likely that marriage traits change slowly through time, and only rapidly change when pressure is put on by outside cultures.

There are a few problems with the methods employed by Walker in this article. He created a basic phylogeny structure by using studies that have tracked mitochondrial DNA to create branches from a common African ancestor. These mitochondrial studies have suffered from many inaccuracies and different studies will create different human population offshoots.

On to this phylogenic tree he overlays known marriage practices of hunter-gatherer groups onto the ends of the branches. Then treating arranged and courtship marriages like genetic traits, he plots back cultural inheritance back to a common African ancestral group, despite the fact that cultural transmission does not follow genetic pathways. This leads him to have to put in “equivocal” nodes when it leads to both courtship and arranged marriages.

It seems like he puts in an obligatory section on how modern hunter-gatherers are not simple relics from the Pleistocene to cover how modern hunter-gatherers don’t create a straight phylogeny. But in the next sentence he disempowers hunter-gatherers by stating how marginal habitats, pressure from agricultural neighbors, and acculturation have all affected HG life-ways to destabilize their marriage practices. In sum, the concept of tracing marriage practices through time is novel, but the methods employed leave a lot to be desired. I remain skeptical about the conclusions of this article until further methodology and analysis can confirm.

Walker RS, Hill KR, Flinn MV, Ellsworth RM (2011) Evolutionary History of Hunter-Gatherer Marriage Practices. PLoS ONE 6(4): e19066