Publications and Talks


Zefferman MR. (2023). Constraints on cooperation shape hierarchical vs distributed structure in human groups. Scientific Reports, 13:1160. [link][pdf][preprint][code & data][supplemental]

Zefferman MR, Mathew S. (2021) Combat stress in a small-scale society suggests divergent evolutionary roots for posttraumatic stress disorder symptoms. Proceedings of the National Academy of Sciences. [code][data][preprint][supplemental]. Press coverage: [Science; The Guardian; ASU News]

Zefferman MR, Mathew S. (2020) An evolutionary theory of moral injury with insight from Turkana warriors. Evolution & Human Behavior. 41:341-353. [link][pdf][code][preprint]

Zefferman MR, Smaldino PE. (2020) Integrating models of cognition and culture will require a bit more math [commentary on Veissière et al]. Behavioral and Brain Sciences. 34:e119. [link][pdf]

Zefferman, MR. (2018) Cultural multilevel selection suggests neither large or small cooperative agreements are likely to solve climate change without changing the game. Sustainability Science. 13(1):109–118. [link][pdf]

Zefferman, MR. (2016) Mothers teach daughters because daughters teach granddaughters: evolution of sex-biased transmission. Behavioral Ecology. 27:1172-1181. [link][pdf][supplemental]

Richerson PJ, R Baldini, A Bell, K Demps, K Frost, V Hillis, S Mathew, E Newton, L Newson, C Ross, P Smaldino, T Waring, MR Zefferman. (2016) Cultural group selection plays an essential role in explaining human cooperation: a sketch of the evidence. Behavioral and Brain Sciences 39:e30-49. [target article][link][pdf]

Richerson PJ, R Baldini, A Bell, K Demps, K Frost, V Hillis, S Mathew, E Newton, L Newson, C Ross, P Smaldino, T Waring, MR Zefferman. (2016) Cultural group selection follows Darwin’s classic syllogism for the operation of selection. Behavioral and Brain Sciences 39:e58-851 [authors’ reply][link][pdf]

EA Cover Zefferman

Zefferman, MR and S Mathew. (2015) An evolutionary theory of large-scale human warfare: group-structured cultural selection. Evolutionary Anthropology. 24:50-61. [link][pdf]

Zefferman, MR, R Baldini and S Mathew. (2015) Solving the puzzle of human warfare requires an explanation of battle raids and cultural institutions. Proceedings of the National Academy of Sciences. 112:E2558. [letter][link][pdf][see also]

Zefferman, MR. (2014) When repentance and forgiveness are possible, direct reciprocity does not explain one-shot generosity, even under arbitrarily high levels of uncertainty. Evolution & Human Behavior. 35:548-549. [response] [link][pdf]

Zefferman, MR. (2014) Direct reciprocity under uncertainty does not explain one-shot cooperation, but demonstrates the benefits of a norm psychology. Evolution & Human Behavior. 35:358-367. [link][pdf][supplemental]

Zefferman, MR, and PJ Richerson. (2014). Many important group-level traits are institutions. Behavioral and Brain Sciences. [commentary] [link][pdf]

Zefferman, MR. (2013) Should the consensus be essentialist and adaptationist? A comment on David Sloan Wilson. Cliodynamics. 4:120-122. [link][pdf]

Zimmerman, MR, R. McElreath and PJ Richerson. (2012) The evolution of cooperation. In Encyclopedia of Theoretical Ecology, eds. A. Hastings and L. Gross. University of California Press. pp. 155-162. [link][pdf]

Pimentel, D, M Herz, M Glickstein, M Zimmerman, et. al. (2002). Renewable energy: current and potential issues. Bioscience 52: 1111-1120. [link][pdf]


2022 A New Synthesis for the Science of Science Workshop, Santa Fe Institute, NM [video]

2020 Evolutionary Psychiatry Webinar Series, Section of Evolutionary Psychiatry, World Psychiatric Association [video]

2020 Club EvMed, Virtual Evolutionary Medicin Conversation, ISEMPH [video]

2019 Role of Information in Complex Conflict Working Group, Santa Fe Institute, NM

2018 Minds, Technology, and Society Seminar Series, UC Merced

2018 Behavior, Evolution and Culture Seminar Series, UCLA

2016 Interdisciplinary Perspectives on Modelling Conflict Workshop, University of Essex

2013 Modeling the Dynamics and Norms of Culture Workshop, University of Michigan

2012 NIMBioS Investigative Workshop on Modeling Social Complexity, Knoxville, TN

2009 Santa Fe Institute Workshop on Frontiers in Complex Systems, Beijing, China


2021 Cultural Evolution Society Meeting (virtual)

2021 International Society for Evolutionary Medicine and Public Health Conference (virtual)

2019 Santa Fe Institute Graduate Workshop on Complex Social Systems Alumni Conference, NM

2018 Cultural Evolution Society Meeting, Tempe, AZ

2018 International Society for Evolution, Medicine & Public Health, Park City, UT

2018 California Workshop on Evolutionary Social Science, UC Santa Barbara

2018 PTSD in Evolutionary and Cross-cultural Perspectives Workshop, Arizona State University

2017 Cultural Evolution Society Inaugural Meeting, Yenna, Germany

2017 American Anthropological Association Annual Meeting, Washington DC

2017 Human Behavior and Evolution Society Annual Meeting, Boise

2016 American Anthropological Association Annual Meeting, Minneapolis

2016 Human Behavior and Evolution Society Annual Meeting, Vancouver, BC

2014 International Society for Research on Aggression World Meeting, Atlanta

2014 Ecological Society of America Annual Meeting, Sacramento

2013 Political Networks Conference, University of Indiana

2011 Game Theory and Society Conference, ETH Zürich, Switzerland

2011 Midwest Political Science Association Conference, Chicago, IL

2010 Midwest Political Science Association Conference, Chicago, IL


2019 NetSci, Burlington, VT

2017 Combat PTSD Conference, San Antonio, TX

2014 Mathematics of Social Learning Workshop, UCLA Institute for Pure & Applied Mathematics

2011 Human Behavior and Evolution Society Annual Meeting, Montpelier, France

2009 The Evolution of Human Aggression Conference, University of Utah