Dyble, M., Salali, G., Chaudhary, N., Page, A. E, Thompson, J., Smith, D., Vinicius, L., Mace, R., and Migliano, A. (2015) Sex equality can explain the unique social structure of hunter-gatherer bands. Science, 348(6236): 796-8.
The social organization of mobile hunter-gatherers has several derived features, including low within-camp relatedness and fluid meta-groups. Although these features have been proposed to have provided the selective context for the evolution of human hypercooperation and cumulative culture, how such a distinctive social system may have emerged remains unclear. We present an agent-based model suggesting that, even if all individuals in a community seek to live with as many kin as possible, within-camp relatedness is reduced if men and women have equal influence in selecting camp members. Our model closely approximates observed patterns of co-residence among Agta and Mbendjele BaYaka hunter-gatherers. Our results suggest that pair-bonding and increased sex egalitarianism in human evolutionary history may have had a transformative effect on human social organization.