Disparate social structures are underpinned by distinct social rules across a primate radiation

J Jacob A. Feder (Institute of Human Origins, Arizona State University) S Susan C. Alberts (Department of Biology, Duke University) E Elizabeth A. Archie (Department of Biological Sciences, University of Notre Dame) M Małgorzata E. Arlet (Institute of Human Biology and Evolution, Faculty of Biology, Adam Mickiewicz University in Poznań) A Alice Baniel (Institut Des Sciences de L’Evolution de Montpellier UMR5554, Centre National de la Recherche Scientifique, Institut de Recherche pour le développement, Université de Montpellier) J Jacinta C. Beehner (Department of Anthropology, University of Michigan) T Thore J. Bergman (Department of Psychology, University of Michigan) A Alecia J. Carter (Department of Anthropology, University College London) M Marie J. E. Charpentier (Institut Des Sciences de L’Evolution de Montpellier UMR5554, Centre National de la Recherche Scientifique, Institut de Recherche pour le développement, Université de Montpellier) K Kenneth L. Chiou (Department of Biology, University of Alabama at Birmingham, Birmingham, AL, USA.) C Catherine Crockford G Guy Cowlishaw (Gobabeb Namib Research Institute) F Federica Dal Pesco (Cognitive Ethology Laboratory, German Primate Center) D David Fernández (Department of Anthropology and Archaeology, University of Calgary) J Julia Fischer (Institut für Anorganische und Analytische Chemie and Freiburg Materials Research Center FMF, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany) J James P. Higham (Department of Anthropology, New York University, New York, NY, USA.) E Elise Huchard (Anthropologie Evolutive, Institut des Sciences de L’Evolution de Montpellier, Université de Montpellier, CNRS, Institut de Recherche pour le Développement) A Auriane Le Floch (The Ape Social Mind Laboratory, Institut des Sciences Cognitives, UMR5229 Centre National de la Recherche Scientifique/Université de Lyon 1) J Julia Lehmann (School of Human and Life Sciences, University of Roehampton) A Amy Lu (Department of Anthropology, Stony Brook University) G Gráinne M. McCabe (Wilder Institute) A Alexander Mielke L Liza R. Moscovice (Psychophysiology Working Group, Research Institute for Farm Animal Biology) B Benjamin Mubemba (Department of Wildlife Sciences, School of Natural Resources, Copperbelt University) M Megan Petersdorf (Department of Anthropology, Tulane University) C Caroline Ross (School of Human and Life Sciences, University of Roehampton) I India A. Schneider-Crease (School of Human Evolution and Social Change, Arizona State University) R Robert M. Seyfarth (Department of Psychology, University of Pennsylvania) N Noah Snyder-Mackler (School of Life Sciences, Arizona State University, Tempe, AZ, USA.) L Larissa Swedell (Department of Anthropology, Queens College and Graduate Center, City University of New York) F Franziska Trede (Cognitive Ethology Laboratory, German Primate Center) J Jenny Tung (Department of Biology, Duke University) A Anna H. Weyher (Department of Anthropology, University of Massachusetts Amherst) R Roman M. Wittig J Jason M. Kamilar (Department of Anthropology, University of Massachusetts Amherst) J Joan B. Silk (School of Human Evolution and Social Change, Arizona State University)

Abstract

Over six decades of research on wild baboons and their close relatives (collectively, the African papionins) have uncovered substantial variation in their behavior and social systems. While most papionins form discrete social groups (single-level societies), a few others form small social units that are nested within larger supergroups (multi-level societies). These two systems are generally thought to be qualitatively distinct, but data from wild populations increasingly suggest that there may be areas of overlap. To quantify this potential gradient in social structure, a more systematic, comparative analysis is needed. Here, we constructed a database of behavioral and demographic records spanning 135 group-years, 28 social groups, 13 long-term field studies, and 11 species to quantify variation in grooming network structure and identify the individual and dyadic properties (e.g., kinship and social status effects) that underlie this variation. Consistent with accumulating field observations, the single-level species could be divided into two categories: cohesive and cliquish . Cohesive single-level networks were dense, kin-biased, and moderately rank-structured, while cliquish single-level networks were more differentiated, slightly more kin-biased, and strongly rank-structured. As expected, multi-level networks were very modular and shaped by females’ ties to specific dominant males but varied in their kin biases. Taken together, these data suggest that in the African papionins i) kin and rank biases are widespread but vary in their strength; ii) male-centered subgroups are exclusive to multi-level systems; and iii) increases in network modularity can emerge in response to heightened nepotism and male-centered clustering.

Article Details

Volume / Issue Vol. 123, Issue 20
Published May 19, 2026
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (36)

J

Jacob A. Feder

Institute of Human Origins, Arizona State University

S

Susan C. Alberts

Department of Biology, Duke University

E

Elizabeth A. Archie

Department of Biological Sciences, University of Notre Dame

M

Małgorzata E. Arlet

Institute of Human Biology and Evolution, Faculty of Biology, Adam Mickiewicz University in Poznań

A

Alice Baniel

Institut Des Sciences de L’Evolution de Montpellier UMR5554, Centre National de la Recherche Scientifique, Institut de Recherche pour le développement, Université de Montpellier

J

Jacinta C. Beehner

Department of Anthropology, University of Michigan

T

Thore J. Bergman

Department of Psychology, University of Michigan

A

Alecia J. Carter

Department of Anthropology, University College London

M

Marie J. E. Charpentier

Institut Des Sciences de L’Evolution de Montpellier UMR5554, Centre National de la Recherche Scientifique, Institut de Recherche pour le développement, Université de Montpellier

K

Kenneth L. Chiou

Department of Biology, University of Alabama at Birmingham, Birmingham, AL, USA.

C

Catherine Crockford

G

Guy Cowlishaw

Gobabeb Namib Research Institute

F

Federica Dal Pesco

Cognitive Ethology Laboratory, German Primate Center

D

David Fernández

Department of Anthropology and Archaeology, University of Calgary

J

Julia Fischer

Institut für Anorganische und Analytische Chemie and Freiburg Materials Research Center FMF, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany

J

James P. Higham

Department of Anthropology, New York University, New York, NY, USA.

E

Elise Huchard

Anthropologie Evolutive, Institut des Sciences de L’Evolution de Montpellier, Université de Montpellier, CNRS, Institut de Recherche pour le Développement

A

Auriane Le Floch

The Ape Social Mind Laboratory, Institut des Sciences Cognitives, UMR5229 Centre National de la Recherche Scientifique/Université de Lyon 1

J

Julia Lehmann

School of Human and Life Sciences, University of Roehampton

A

Amy Lu

Department of Anthropology, Stony Brook University

G

Gráinne M. McCabe

Wilder Institute

A

Alexander Mielke

L

Liza R. Moscovice

Psychophysiology Working Group, Research Institute for Farm Animal Biology

B

Benjamin Mubemba

Department of Wildlife Sciences, School of Natural Resources, Copperbelt University

M

Megan Petersdorf

Department of Anthropology, Tulane University

C

Caroline Ross

School of Human and Life Sciences, University of Roehampton

I

India A. Schneider-Crease

School of Human Evolution and Social Change, Arizona State University

R

Robert M. Seyfarth

Department of Psychology, University of Pennsylvania

N

Noah Snyder-Mackler

School of Life Sciences, Arizona State University, Tempe, AZ, USA.

L

Larissa Swedell

Department of Anthropology, Queens College and Graduate Center, City University of New York

F

Franziska Trede

Cognitive Ethology Laboratory, German Primate Center

J

Jenny Tung

Department of Biology, Duke University

A

Anna H. Weyher

Department of Anthropology, University of Massachusetts Amherst

R

Roman M. Wittig

J

Jason M. Kamilar

Department of Anthropology, University of Massachusetts Amherst

J

Joan B. Silk

School of Human Evolution and Social Change, Arizona State University