title: Networks of Food Sharing Reveal the Functional Significance of Multilevel Sociality in Two Hunter-Gatherer Groups.
abstract: Like many other mammalian and primate societies [1-4], humans are said to live in multilevel social groups, with individuals situated in a series of hierarchically structured sub-groups [5, 6]. Although this multilevel social organization has been described among contemporary hunter-gatherers [5], questions remain as to the benefits that individuals derive from living in such groups. Here, we show that food sharing among two populations of contemporary hunter-gatherers-the Palanan Agta (Philippines) and Mbendjele BaYaka (Republic of Congo)-reveals similar multilevel social structures, with individuals situated in households, within sharing clusters of 3-4 households, within the wider residential camps, which vary in size. We suggest that these groupings serve to facilitate inter-sexual provisioning, kin provisioning, and risk reduction reciprocity, three levels of cooperation argued to be fundamental in human societies [7, 8]. Humans have a suite of derived life history characteristics including a long childhood and short inter-birth intervals that make offspring energetically demanding [9] and have moved to a dietary niche that often involves the exploitation of difficult to acquire foods with highly variable return rates [10-12]. This means that human foragers face both day-to-day and more long-term energetic deficits that conspire to make humans energetically interdependent. We suggest that a multilevel social organization allows individuals access to both the food sharing partners required to buffer themselves against energetic shortfalls and the cooperative partners required for skill-based tasks such as cooperative foraging.
authors.affiliation: Anthropology, University College London, London WC1E 6BT, UK. Electronic address: mark.dyble.12@ucl.ac.uk.
authors.forename: Mark
authors.initials: M
authors.lastname: Dyble
authors.affiliation: Anthropology, University College London, London WC1E 6BT, UK.
authors.forename: James
authors.initials: J
authors.lastname: Thompson
authors.affiliation: Anthropology, University College London, London WC1E 6BT, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Smith
authors.affiliation: Anthropology, University College London, London WC1E 6BT, UK.
authors.forename: Gul Deniz
authors.initials: GD
authors.lastname: Salali
authors.affiliation: Anthropology, University College London, London WC1E 6BT, UK.
authors.forename: Nikhil
authors.initials: N
authors.lastname: Chaudhary
authors.affiliation: Anthropology, University College London, London WC1E 6BT, UK.
authors.forename: Abigail E
authors.initials: AE
authors.lastname: Page
authors.affiliation: Anthropology, University College London, London WC1E 6BT, UK.
authors.forename: Lucio
authors.initials: L
authors.lastname: Vinicuis
authors.affiliation: Anthropology, University College London, London WC1E 6BT, UK.
authors.forename: Ruth
authors.initials: R
authors.lastname: Mace
authors.affiliation: Anthropology, University College London, London WC1E 6BT, UK.
authors.forename: Andrea Bamberg
authors.initials: AB
authors.lastname: Migliano
mesh_terms: D003223:Congo; D003299:Cooperative Behavior; D005260:Female; D005502:Food; D006801:Humans; D008297:Male; D010679:Philippines