Sarah Brosnan, Ph.D.

Associate Professor

Department of Psychology
Georgia State University, Atlanta, GA


B.A., Biology, Baylor University, Waco, TX, 1998
Ph.D., Population Biology, Ecology and Evolution, Emory University, Atlanta, GA, 2004
FIRST Postdoctoral Fellow, Emory College of Arts and Sciences, Department of Anthropology, 2004-2007

Research Statement

My main interests are the evolution of social behavior and social cognition, particularly the cognitive processes underlying cooperation and reciprocity and economic behavior. Specifically, I am interested in the proximate mechanisms underlying such behaviors, particularly how animals perceive the value of different commodities in their reciprocal interactions (i.e. goods and services exchanged within a biological market) and how the social environment affects the acquisition and use of such a concept of value. I am currently working on a number of different projects in both humans and nonhuman primates (particularly chimpanzees) in an effort to understand more about the evolution of cooperative and economic behavior across the primate lineage.


Grant Support

Current Funding

Funding Agency: NSF/SES (Division of Social and Economic Sciences)
Project Title: Collaborative Research: Expectations About Reward Outcomes
Project Period: 9/15/2014 - 8/31/2018
Total Award: $394,563
See: Notice of Award

Funding Agency: NSF/SES (Division of Social and Economic Sciences)
Project Title: Collaborative Research: Primate and Human Social Decision-Making
Project Period: 9/15/2011 - 8/15/2016
Total Award: $475,217
See: Notice of Award

Past Funding
Funding Agency: NSF/SES (Division of Social and Economic Sciences)
Project Title: Career: Understanding Responses to Inequitable Outcomes in Non-Human Primates
Project Period: 7/01/2009 - 6/30/2014
Total Award: $677,462
See: Notice of Award



Recent Publications

Beran, M.J., Hopper, L.M., de Waal, F.B., Sayers, K., Brosnan, S.F. (2015) Chimpanzee food preferences, associative learning, and the origins of cooking.  Learn Behav. 2015 Dec 10. [Epub ahead of print]

Morton, F.B., Brosnan, S.F., Prétôt, L., Buchanan-Smith, H.M., O'Sullivan, E., Stocker, M., D'Mello, D., Wilson, V.A. (2016) Using photographs to study animal social cognition and behaviour: Do capuchins' responses to photos reflect reality? Behav Processes. 124:38-46.

Parrish, A.E., Brosnan, S.F., Beran, M.J. (2015)  Do you see what I see? A comparative investigation of the Delboeuf illusion in humans (Homo sapiens), rhesus monkeys (Macaca mulatta), and capuchin monkeys (Cebus apella). J Exp Psychol Anim Learn Cogn. 41:395-405. PMCID: PMC4594174

Brosnan, S.F., Hopper, L.M., Richey, S., Freeman, H.D., Talbot, C.F., Gosling, S.D., Lambeth, S.P., Schapiro, S.J. (2015) Personality influences responses to inequity and contrast in chimpanzees. Anim Behav. 101:75-87. PMCID: PMC4337034

Claidière, N., Whiten, A., Mareno, M.C., Messer, E.J., Brosnan, S.F., Hopper, L.M., Lambeth, S.P., Schapiro, S.J., McGuigan, N. (2015) Selective and contagious prosocial resource donation in capuchin monkeys, chimpanzees and humans. Sci Rep. 5:7631.  PMCID: PMC4284509

Pasquaretta, C., Levé, M., Claidière, N., van de Waal, E., Whiten, A., MacIntosh, A.J., Pelé, M., Bergstrom, M.L., Borgeaud, C., Brosnan, S.F., Crofoot, M.C., Fedigan, L.M., Fichtel, C., Hopper, L.M., Mareno, M.C., Petit, O., Schnoell, A.V., di Sorrentino, E.P., Thierry, B., Tiddi, B., Sueur, C. (2014) Social networks in primates: smart and tolerant species have more efficient networks. Sci Rep. 4:7600. PMCID: PMC4274513

Brosnan, S.F., de Waal, F.B. (2014) Evolution of responses to (un)fairness. Science. 346(6207):1251776. Review.

Lamichhane, B., Adhikari, B.M., Brosnan, S.F., Dhamala, M. (2014) The neural basis of perceived unfairness in economic exchanges. Brain Connect. 4(8):619-30. PMCID: PMC4203022

Hopper, L.M., Lambeth, S.P., Schapiro, S.J., Brosnan, S.F. (2014) Social comparison mediates chimpanzees' responses to loss, not frustration. Anim Cogn. 2014 Nov;17(6):1303-11. doi: 10.1007/s10071-014-0765-9. Epub 2014 Jun 1.

Lefevre, C.E., Wilson, V.A., Morton, F.B., Brosnan, S.F., Paukner, A., Bates, T.C. (2014) Facial width-to-height ratio relates to alpha status and assertive personality in capuchin monkeys. PLoS One. 9(4):e93369. PMCID: PMC3976278

Proctor, D., Williamson, R.A., Latzman, R. A., and Brosnan, S.F. (2014) Gambling primates: Reactions to a modified Iowa gambling task in humans, chimpanzees and capuchin monkeys. Animal Cognition, 17:983-95. PMCID: PMC4137781

Proctor, D., Williamson,, R.A, de Waal, F.B., Brosnan, S.F. (2013) Reply to Henrich and Silk: Toward a unified explanation for apes and humans. Proc Natl Acad Sci U S A. 110:E3050. PMCID: PMC3746903

Freeman, H.D., Sullivan, J., Hopper, L.M., Talbot, C.F., Holmes, A.N., Schultz-Darken, N., Williams, L.E., Brosnan, S.F. (2013) Different responses to reward comparisons by three primate species. PLoS One. 8:e76297. PMCID: PMC3794049

Hopper, L.M., Lambeth, S.P., Schapiro, S.J., Brosnan, S.F. (2013) When given the opportunity, chimpanzees maximize personal gain rather than "level the playing field".  PeerJ. 1:e165. PMCID: PMC3792176

Drayton, L.A., Brosnan, S.F., Carrigan, J., Stoinski, T.S. (2013) Endowment Effects in Gorillas (Gorilla gorilla).  J Comp Psychol. 127:365-9.

Brosnan, S.F., Beran, M.J., Parrish, A.E., Price, S.A., Wilson, B.J. (2013) Comparative approaches to studying strategy: towards an evolutionary account of primate decision making.  Evol Psychol. 11:606-627.

Proctor, D., Williamson, R.A., de Waal, F.B., Brosnan, S.F. (2013) Reply to Jensen et al.: Equitable offers are not rationally maximizing. Proc Natl Acad Sci USA;110(20):E1838. PMCID: PMC3657811

Brosnan, S.F. (2013) Justice- and fairness-related behaviors in nonhuman primates. Proc Natl Acad Sci U S A. 110 Suppl 2:10416-23. PMCID: PMC3690609

Freeman, H.D., Brosnan, S.F., Hopper, L.M., Lambeth, S.P., Schapiro, S.J., Gosling, S.D. (2013) Developing a comprehensive and comparative questionnaire for measuring personality in chimpanzees using a simultaneous top-down/bottom-up design. Am J Primatol. 75:1042-53.

Proctor, D., Brosnan, S.F., de Waal, F.B. (2013) How fairly do chimpanzees play the ultimatum game? Commun Integr Biol.; 6:e23819. PMCID: PMC3656016

Morton, F.B., Lee, P.C., Buchanan-Smith, H.M., Brosnan, S.F., Thierry, B., Paukner, A., de Waal, F.B., Widness, J., Essler, J.L., Weiss, A. (2013) Personality structure in brown capuchin monkeys (Sapajus apella): comparisons with chimpanzees (Pan troglodytes), orangutans (Pongo spp.), and rhesus macaques (Macaca mulatta). J Comp Psychol.;127(3):282-98. PMCID: PMC3744614

Proctor, D., Williamson, R.A., de Waal, F.B.M., & Brosnan, S.F. (2013) Chimpanzees play the ultimatum game. Proc Nat Acad Sci;110(6):2070-5. PMCID: PMC3568338

Brosnan, S.F., Wilson, B.J., Beran, M.J. (2012) Old World monkeys are more similar to humans than New World monkeys when playing a coordination game.  Proc Biol Sci. 279(1733):1522-30.

Brosnan, S.F. (2011) Property in nonhuman primates.  New Dir Child Adolesc Dev. 2011(132):9-22.

Brosnan, S.F., Flemming, T., Talbot, C.F., Mayo, L., Stoinski, T. (2011) Orangutans (Pongo pygmaeus) do not form expectations based on their partner's outcomes.  Folia Primatol (Basel). 82(1):56-70.

Proctor, D.P., Lambeth, S.P., Schapiro, S.J., Brosnan, S.F. (2011) Male chimpanzees' grooming rates vary by female age, parity, and fertility status.  Am J Primatol. 73(10):989-96. PMCID: PMC3166388

Brosnan, S.F. (2011) A Hypothesis of the Co-evolution of Cooperation and Responses to Inequity.  Front Neurosci. 5:43.  PMCID: PMC3077916

Talbot, C.F., Freeman, H.D., Williams, L.E., Brosnan, S.F. (2011) Squirrel monkeys' response to inequitable outcomes indicates a behavioural convergence within the primates.  Biol Lett. 7(5):680-2. PMCID: PMC3169057

Brosnan, S.F., Parrish, A., Beran, M.J, Flemming, T., Heimbauer, L., Talbot, C.F., Lambeth, S.P., Schapiro, S.J., Wilson, B.J.  (2011) Responses to the Assurance game in monkeys, apes, and humans using equivalent procedures. Proc Natl Acad Sci U S A. 108(8):3442-7. PMCID: PMC3044417

Brosnan, S.F., Salwiczek, L., Bshary, R. (2010) The interplay of cognition and cooperation. Philos Trans R Soc Lond B Biol Sci. 365(1553):2699-710.

Brosnan, S.F., Bshary, R. (2010) Cooperation and deception: from evolution to mechanisms.
Philos Trans R Soc Lond B Biol Sci. 365(1553):2593-8.

Brosnan, S.F. (2010) Behavioral development: timing is everything. Curr Biol. 20(3):R98-R100.

Brosnan, S.F., Newton-Fisher, N.E., Vugt, M.V. (2009) A Melding of the Minds: When Primatology Meets Personality and Social Psychology. Pers Soc Psychol Rev. 13(2):129-47.

Brosnan, S.F., Silk, J.B., Henrich, J., Mareno, M.C., Lambeth, S.P., Schapiro, S.J. (2009) Chimpanzees (Pan troglodytes) do not develop contingent reciprocity in an experimental task. Anim Cogn. 12(4):587-97.

Brosnan, S.F.  (2009) Animal behavior: the right tool for the job. Curr Biol. 19(3):R124-5. Review.

Brosnan, S.F., Grady, M.F., Lambeth, S.P., Schapiro, S.J., Beran, M.J. (2008) Chimpanzee autarky. PLoS ONE.  3(1):e1518.

Brosnan SF. (2008) How primates (including us!) respond to inequity. Adv Health Econ Health Serv Res. 20:99-124.

Brosnan, S.F. (2007) Our social roots. Nature. 450(7173):1160-1161.

Silk, J. B., Brosnan, S. F., Vonk, J., Henrich, J., Povinelli, D., Richardson, L., Susan, A., Mascaro, Jenny, and Shapiro, Steve. (2006) Animal Behavior: Chimpanzee choice and prosociality (Reply). Nature 440: E6.

Brosnan, S. F. (2006) An exploration of culture: Review of “The cultured Chimpanzee: Reflections on cultural primatology” by William McGrew. American Journal of Primatology 68: 425-427.

Silk, J. B., Brosnan, S. F., Vonk, J., Henrich, J., Povinelli, D., Richardson, L., Susan, A., Mascaro, J., and Shapiro, S. (2005) Chimpanzees are indifferent to the welfare of unrelated group members. Nature 437: 1357-1359.

Chapters, Reviews and Commentaries

Brosnan, S. F. (2007) Fairness and Other-regarding Preferences in Nonhuman Primates. In: MORAL MARKETS: THE CRITICAL ROLE OF VALUES IN THE ECONOMY, Paul J. Zak, ed., Princeton University Press, Available at SSRN:

de Waal, F. B. M. and Brosnan, S. F. (2006) Simple and complex social reciprocity in monkeys and apes. In: Cooperation in Primates and Humans: Mechanisms and Evolution. ed. Peter Kappeler & Carel van Schaik. Springer Press.


Georgia State University
Department of Psychology
Language Research Center
P.O. Box 5010
Atlanta, GA 30302-5010
Tel: 404.413.6301 or 404.241.8164
Fax: 404.413.6207
Lab webpage:
Personal webpage:


Emory University School of Medicine
Department of Physiology
Atlanta, GA 30322-3110
(404) 727-7410 Office ~ (404) 727-2648 FAX

For questions or comments, contact the webmaster at