Social networks and cooperation in hunter-gatherers.
Open accessAbstract
Social networks show striking structural regularities, and both theory and evidence suggest that networks may have facilitated the development of large-scale cooperation in humans. Here, we characterize the social networks of the Hadza, a population of hunter-gatherers in Tanzania. We show that Hadza networks have important properties also seen in modernized social networks, including a skewed degree distribution, degree assortativity, transitivity, reciprocity, geographic decay and homophily. We demonstrate that Hadza camps exhibit high between-group and low within-group variation in public goods game donations. Network ties are also more likely between people who give the same amount, and the similarity in cooperative behaviour extends up to two degrees of separation. Social distance appears to be as important as genetic relatedness and physical proximity in explaining assortativity in cooperation. Our results suggest that certain elements of social network structure may have been present at an early point in human history. Also, early humans may have formed ties with both kin and non-kin, based in part on their tendency to cooperate. Social networks may thus have contributed to the emergence of cooperation.
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Brain size reduction occurred in traditional hunter-gatherer human populations that never adopted sedentary agricultural practices, but have complex social networks.
“Brain size reduction occurred in traditional hunter-gatherer human populations (Wiercinski, 1979) that never adopted sedentary agricultural practices, but have complex social networks (Apicella et al., 2012).”
From When and Why Did Human Brains Decrease in Size? A New Change-Point Analysis and Insights From Brain Evolution in Ants (2021) · cites this paper as Apicella et al., 2012
For most of our evolutionary past, individual H. sapiens may have maintained meaningful social contacts with, at most, hundreds of others and often far fewer.
“For most of our evolutionary past, individual H. sapiens may have maintained meaningful social contacts with, at most, hundreds of others and often far fewer”
From Stewardship of global collective behavior (2021) · cites this paper as [69]
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Cites
Emergence of Scaling in Random Networks
Barabási, A.-L., & Albert, R. (1999) · Science · doi:10.1126/science.286.5439.509 · Cited by 36,135 · see citing works
Longitudinal data analysis using generalized linear models
LIANG, K.-Y., & ZEGER, S. L. (1986) · Biometrika · doi:10.1093/biomet/73.1.13 · Cited by 18,550 · see citing works
Five Rules for the Evolution of Cooperation
Nowak, M. A. (2006) · Science · doi:10.1126/science.1133755 · Cited by 5,894 · see citing works
Fehr, E., & Fischbacher, U. (2003) · Nature · doi:10.1038/nature02043 · Cited by 3,475 · cited 1× · see citing works
“Hadza networks also resemble modernized human networks insofar as they too differ from random networks with respect to reciprocit”
BackgroundIn Search of Homo Economicus: Behavioral Experiments in 15 Small-Scale Societies
Henrich, J., Boyd, R. T., Bowles, S., Camerer, C., Fehr, E., Gintis, H. M., & McElreath, R. L. (2001) · American Economic Review · doi:10.1257/aer.91.2.73 · Cited by 2,619 · see citing works
A simple rule for the evolution of cooperation on graphs and social networks
Ohtsuki, H., Hauert, C., Lieberman, E., & Nowak, M. A. (2006) · Nature · doi:10.1038/nature04605 · Cited by 2,208 · see citing works
Structure and tie strengths in mobile communication networks
Onnela, J.-P. “., Saramäki, J., Hyvönen, J., Szabó, G., Lazer, D., Kaski, K. K., Kertész, J., & Barabási, A.-Ĺ. (2007) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0610245104 · Cited by 1,937 · see citing works
Nowak, M. A., Tarnita, C. E., & Wilson, E. O. (2010) · Nature · doi:10.1038/nature09205 · Cited by 1,483 · see citing works
Moral Sentiments and Material Interests
(2005) · The MIT Press eBooks · doi:10.7551/mitpress/4771.001.0001 · Cited by 937 · see citing works
Co-Residence Patterns in Hunter-Gatherer Societies Show Unique Human Social Structure
Hill, K. R., Walker, R. S., Božičević, M., Eder, J., Headland, T., Hewlett, B., Hurtado, A. M., Marlowe, F., Wiessner, P., & Wood, B. (2011) · Science · doi:10.1126/science.1199071 · Cited by 863 · see citing works
Self-citationAnalyzing Animal Societies: Quantitative Methods for Vertebrate Social Analysis
Whitehead, H. (2008) · University of Chicago Press eBooks · doi:10.7208/chicago/9780226895246.001.0001 · Cited by 809 · see citing works
Cooperative behavior cascades in human social networks
Fowler, J. H., & Christakis, N. A. (2010) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0913149107 · Cited by 767 · see citing works
Self-citationThe evolution of reciprocity in sizable groups
Boyd, R. T., & Richerson, P. J. (1988) · Journal of Theoretical Biology · doi:10.1016/s0022-5193(88)80219-4 · Cited by 714 · see citing works
The evolution of strong reciprocity: cooperation in heterogeneous populations
Bowles, S., & Gintis, H. M. (2003) · Theoretical Population Biology · doi:10.1016/j.tpb.2003.07.001 · Cited by 707 · see citing works
Krebs, D. L. (1975) · Journal of Personality and Social Psychology · doi:10.1037//0022-3514.32.6.1134 · Cited by 653 · see citing works
Dynamic social networks promote cooperation in experiments with humans
Rand, D. G., Arbesman, S., & Christakis, N. A. (2011) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1108243108 · Cited by 653 · see citing works
Self-citationWhy Culture Is Common, but Cultural Evolution Is Rare
Boyd, R. T., & Richerson, P. J. (2005) · doi:10.1093/oso/9780195165241.003.0004 · Cited by 608 · see citing works
Group Competition, Reproductive Leveling, and the Evolution of Human Altruism
Bowles, S. (2006) · Science · doi:10.1126/science.1134829 · Cited by 604 · see citing works
Analyzing animal societies: quantitative methods for vertebrate social analysis
(2009) · Choice Reviews Online · doi:10.5860/choice.46-5619 · Cited by 601 · see citing works
The Hadza: hunter-gatherers of Tanzania
(2011) · Choice Reviews Online · doi:10.5860/choice.48-2768 · Cited by 559 · see citing works
Name generators in surveys of personal networks
Campbell, K. E., & Lee, B. A. (1991) · Social Networks · doi:10.1016/0378-8733(91)90006-f · Cited by 423 · see citing works
Krebs, D. (1975) · Journal of Personality and Social Psychology · doi:10.1037/0022-3514.32.6.1134 · Cited by 417 · see citing works
The evolution of indirect reciprocity
Boyd, R., & Richerson, P. J. (1989) · Social Networks · doi:10.1016/0378-8733(89)90003-8 · Cited by 398 · see citing works
The complex structure of hunter–gatherer social networks
Hamilton, M., Milne, B., Walker, R. S., Burger, O. F., & Brown, J. H. (2007) · Proceedings of the Royal Society of London. Biological Sciences · doi:10.1098/rspb.2007.0564 · Cited by 357 · see citing works
Geographic Constraints on Social Network Groups
Onnela, J.-P. “., Samuel Arbesman, C., González, M. C., Barabási, A.-Ĺ., & Christakis, N. A. (2011) · PLoS ONE · doi:10.1371/journal.pone.0016939 · Cited by 351 · see citing works
Self-citationDavis, J. A. (1970) · American Sociological Review · doi:10.2307/2093295 · Cited by 329 · see citing works
Hawkes, K., O’Connell, J., & Jones, N. G. B. (2001) · Evolution and Human Behavior · doi:10.1016/s1090-5138(00)00066-0 · Cited by 285 · see citing works
Assortment of encounters and evolution of cooperativeness
Eshel, I., & Cavalli-Sforza, L. L. (1982) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.79.4.1331 · Cited by 274 · see citing works
FriendshipDevelopment, Ecology, and Evolution of a Relationship
Hruschka, D. (2010) · doi:10.1525/california/9780520265462.001.0001 · Cited by 273 · see citing works
Kaplan, H. S., & Gurven, M. (2005) · The MIT Press eBooks · doi:10.7551/mitpress/4771.003.0007 · Cited by 259 · see citing works
Model of genetic variation in human social networks
Fowler, J. H., Dawes, C. T., & Christakis, N. A. (2009) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0806746106 · Cited by 245 · see citing works
Self-citationCorrelated genotypes in friendship networks
Fowler, J. H., Settle, J. E., & Christakis, N. A. (2011) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1011687108 · Cited by 188 · see citing works
Self-citationWealth Transmission and Inequality among Hunter‐Gatherers
Smith, E. A., Hill, K. R., Marlowe, F. W., Nolin, D. A., Wiessner, P., Gurven, M., Bowles, S., Mulder, M. B., Hertz, T., & Bell, A. (2010) · Current Anthropology · doi:10.1086/648530 · Cited by 171 · see citing works
Self-citationSocial network analysis in the study of nonhuman primates: A historical perspective
Brent, L. J. N., Lehmann, J., & Ramos‐Fernández, G. (2011) · American Journal of Primatology · doi:10.1002/ajp.20949 · Cited by 133 · see citing works
Sex Differences in Food Preferences of Hadza Hunter-Gatherers
Berbesque, J. C., & Marlowe, F. W. (2009) · Evolutionary Psychology · doi:10.1177/147470490900700409 · Cited by 90 · see citing works
Self-citationCole, T., & Teboul, J. B. (2004) · Personal Relationships · doi:10.1111/j.1475-6811.2004.00075.x · Cited by 84 · see citing works
From Forest to Reservation: Transitions in Food-Sharing Behavior among the Ache of Paraguay
Gurven, M., Hill, K. R., & Kaplan, H. S. (2002) · Journal of Anthropological Research · doi:10.1086/jar.58.1.3631070 · Cited by 79 · see citing works
The impact of network clustering and assortativity on epidemic behaviour
Badham, J., & Stocker, R. (2009) · Theoretical Population Biology · doi:10.1016/j.tpb.2009.11.003 · Cited by 78 · see citing works
Schildcrout, J. S. (2005) · Biostatistics · doi:10.1093/biostatistics/kxi033 · Cited by 70 · see citing works
Cooperation in Heterogeneous Populations
Sigmund, K., & Nowak, M. A. (1994) · Recent research in psychology · doi:10.1007/978-1-4612-4308-3_17 · Cited by 7 · see citing works
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Bond, R. M., Fariss, C. J., Jones, J. J., Kramer, A. D. I., Marlow, C., Settle, J. E., & Fowler, J. H. (2012) · Nature · doi:10.1038/nature11421 · Cited by 2,575 · see citing works
Self-citationSocial contagion theory: examining dynamic social networks and human behavior
Christakis, N. A., & Fowler, J. H. (2013) · Statistics in Medicine · doi:10.1002/sim.5408 · Cited by 1,303 · see citing works
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Muchnik, L., Aral, S., & Taylor, S. J. (2013) · Science · doi:10.1126/science.1240466 · Cited by 871 · see citing works
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Parkinson, C., Kleinbaum, A. M., & Wheatley, T. (2018) · Nature Communications · doi:10.1038/s41467-017-02722-7 · Cited by 388 · see citing works
Kim, D. A., Hwong, A. R., Stafford, D., Hughes, D. A., O'Malley, A. J., Fowler, J. H., & Christakis, N. A. (2015) · The Lancet · doi:10.1016/s0140-6736(15)60095-2 · Cited by 350 · see citing works
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“Brain size reduction occurred in traditional hunter-gatherer human populations (Wiercinski, 1979) that never adopted sedentary agricultural practices, but have complex social networks (Apicella et al., 2012).”
BackgroundLi, N. P., & Kanazawa, S. (2016) · British Journal of Psychology · doi:10.1111/bjop.12181 · Cited by 85 · see citing works
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- Authors
- Apicella, C. L., Marlowe, F. W., Fowler, J. H., & Christakis, N. A.
- Affiliations
- Harvard University (US)
- University of Cambridge (GB)
- University of California San Diego (US)
- Corresponding author
- Christakis, Nicholas A.
- Venue
- Nature
- Published
- 2012-01
- Volume
- 481
- Issue
- 7382
- Pages
- 497-501
- ISSN
- 0028-0836 (ISSN-L)
- 1476-4687
- PMC
- PMC3340565
- OpenAlex
- W1966344422
- Cited by
- 698
- References
- 40
- Citations by year
- 2026: 18 · 2025: 27 · 2024: 36 · 2023: 41 · 2022: 54 · 2021: 54 · 2020: 50 · 2019: 81 · 2018: 56 · 2017: 52 · 2016: 44 · 2015: 69 · 2014: 55 · 2013: 38 · 2012: 23
- FWCI
- 193.97
- Type
- journal article
- Language
- en
- Open access
- green
- www.ncbi.nlm.nih.gov
- Licence
- www.springer.com/tdm (tdm)
- Locations
- Nature (publishedVersion)
- PubMed (publishedVersion)
- PubMed Central (acceptedVersion)
- RePEc: Research Papers in Economics (submittedVersion)
- eScholarship (California Digital Library) (submittedVersion)
- Funders
- National Institute on Aging (P01AG031093)
- National Institute of General Medical Sciences (P41GM103504)
- Topics
- Social Sciences › Sociology and Political Science › Evolutionary Game Theory and Cooperation
- Social Sciences › Cultural Studies › Language and cultural evolution
- Physical Sciences › Physics and Astronomy › Statistical and Nonlinear Physics › Complex Network Analysis Techniques
- Keywords
- social networks, cooperation, Hadza, hunter-gatherers, emergence of cooperation, public goods game, homophily, assortativity, transitivity, reciprocity, degree distribution, social distance, kinship, early human evolution, network structure
- MeSH terms
- Anthropology, Cooperative Behavior, Biological Evolution, Game Theory, Humans, Probability, Rural Population, Social Support, Tanzania, Wilderness
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