Title
Hierarchical social modularity in gorillas
Author(s)
Morrison, Robin E.;Groenenberg, Milou;Breuer, Thomas;Manguette, Marie L.;Walsh, Peter D.
Published
2019
Publisher
Proceedings of the Royal Society B: Biological Sciences
Abstract
Modern human societies show hierarchical social modularity (HSM) in which lower-order social units like nuclear families are nested inside increasingly larger units. It has been argued that this HSM evolved independently and after the chimpanzee –human split due to greater recognition of, and bonding between, dispersed kin. We used network modularity analysis and hierarchical clustering to quantify community structure within two western lowland gorilla populations. In both communities, we detected two hierarchically nested tiers of social structure which have not been previously quantified. Both tiers map closely to human social tiers. Genetic data from one population suggested that, as in humans, social unit membership was kin structured. The sizes of gorilla social units also showed the kind of consistent scaling ratio between social tiers observed in humans, baboons, toothed whales, and elephants. These results indicate that the hierarchical social organization observed in humans may have evolved far earlier than previously asserted and may not be a product of the social brain evolution unique to the hominin lineage.
Keywords
Gorilla;social structure;hierarchical,;modularity;community;multi-level
Access Full Text
A full-text copy of this article may be available. Please email the WCS Library to request.
![]()
Back
PUB24839