We may think that not wanting to live around relatives is a modern trait, but our closest anthropological relatives, modern day hunter-gatherers, choose to not live among family members as much as we think. That goes for when males and females have the choice.

Hunter-gatherer populations have large numbers of unrelated individuals but it seems like they live with kin. Do couples always move? M. Dyble and colleagues developed a model of behavior to study it - running two versions, one where both the husband and wife in a hunter-gatherer couple could have equal influence over where their household would reside, and another where only one sex had influence. The model showed that when both men and women had say over their living situation, with both husband and wife striving to maximize numbers of kin in their camp, communities were much less closely related than when only men or only women could choose. For calibration, they found data from two contemporary hunter-gatherer societies in Africa and the Philippines that matched the model closely.

Sexual equality seems to reduce relatedness of the people in a camp at any one time, the researchers say, but, critically, it increases the number of camps where an individual has one or more kin living, paving the way for cooperation and information exchange among groups without the need for more complex drivers, like wealth or war.

Citation: "Sex equality can explain the unique social structure of hunter-gatherer bands," by M. Dyble; G.D. Salali; N. Chaudhary; A. Page; D. Smith; J. Thompson; L. Vinicius; R. Mace; A.B. Migliano at University College London (UCL) in London, UK.