The quality of relationships and the social organization of a society, influence the transfer of valuable resources not only in humans but also in other primates. Researchers at the German Primate Center (DPZ) – Leibniz Institute for Primate Research in Göttingen have discovered this using the example of Guinea baboons (Papio papio), which distribute meat according to patterns similar to those of human hunter-gatherer groups. The team analyzed 109 meat-eating events and combined these records with behavioral data from nearly a decade of field research. The closer the relationship between two animals, the more likely and peaceful the transfer of meat was. In contrast, theft occurred among less closely related group members (iScience).
The sharing of a valuable resource, such as meat, is considered a key driver for the development of complex, multi-level societies among humans. The varying success of hunting, combined with the high nutritional value of hunted animals, led early humans to develop networks between households to ensure a regular supply of meat. In human hunter-gatherer societies, meat is an essential food source that is rarely available and is widely shared according to the community structure, first within households and then within camps. However, the distribution of essential goods within human social structures is accompanied by culturally determined social norms and traditions. To better understand how a multi-level social organization influences the sharing of resources within a society, it is of great value to study other multi-level social systems among our closest relatives.
Tolerant sharing at the base of the society
To address this question, researchers from the Cognitive Ethology Laboratory at the German Primate Center spent nine years observing Guinea baboons in Senegal. These animals live in a multi-level social system. The smallest social unit is the “unit,” consisting of one male, one to several associated females, and their offspring. Three to four “units” together form a “party,” which is connected by long-term bonds between males often underpinned by kinship. Finally, the two to three parties together form the third level – the “gang.” Relationships between individuals tend to be stronger at lower levels of the society.
At the DPZ field station in Simenti, the scientists analyzed a total of 320 instances of meat transfers, mostly by male baboons with females in their units or with other males in the same party. The stronger the relationship between two animals, the greater the chance of meat transferring between them. Tolerant transfers, in which animals took pieces of meat without conflict (“passive sharing”), occurred almost exclusively within the closest social units. Further up in the hierarchy of social levels—between different units or within the gang—the transfers became less frequent and less tolerant.
“We were able to show that Guinea baboons pass meat along their social bonds,” explains William J. O'Hearn, lead author of the study. “This form of tolerant sharing is reminiscent of the behavior of human hunter-gatherer groups, where meat is first distributed within the family and only then reaches more distant acquaintances or neighbors.”
Social relationship strength determines who gets what
For their analysis, the researchers combined direct behavioral observations with statistical models to calculate the strength of the relationships between the animals. The results showed that the probability of getting a piece of meat increased significantly with the strength of individuals’ relationships to the “owner.”
Interestingly, Guinea baboons do not actively share their meat—they do not deliberately offer pieces of meat to others. Instead, meat is usually passed on “passively”: one animal eats, leaves the carcass behind, and the next socially proximal animal takes over. This observation suggests that social tolerance is a crucial prerequisite for the exchange of meat among baboons.
Significance for understanding social evolution
The study provides important evidence that complex social structures—i.e., societies with nested multiple levels—can have similar effects on the exchange of resources, regardless of the species. “This suggests that certain social patterns may have developed independently in humans and non-human primates, but in comparable ways,” says Julia Fischer, head of the Cognitive Ethology Laboratory at the DPZ.