Review of Behavioral Economics > Vol 11 > Issue 1

Assume a Chimpanzee: The Default Model of Economic Choice

Arthur O’Sullivan, Department of Economics, Lewis & Clark College, USA,
Suggested Citation
Arthur O’Sullivan (2024), "Assume a Chimpanzee: The Default Model of Economic Choice", Review of Behavioral Economics: Vol. 11: No. 1, pp 43-71.

Publication Date: 22 Feb 2024
© 2024 A. O’Sullivan
Economic theory
JEL Codes: A00, A11, A20, D90
Economic choicerationalitysocial norms


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In this article:
1. Introduction 
2. Collaboration and Sharing 
3. Incurring a Cost to Enforce a Social Norm 
4. Respecting Ownership 
5. Conformity and Imitation 
6. Benefits from Imitation: Social Learning 
7. Summary 


The default model of economic choice – used in economics instruction and in the bulk of scholarship in microeconomics – assumes that decision makers are selfish. As shown by behavioral scientists, this assumption is consistent with chimpanzee behavior, but inconsistent with human behavior. Unlike chimpanzees, humans share the rewards of collaboration, engage in third-party punishment of norm violators, and respect ownership. In addition, the choice model implicitly rules out conformity and over-imitation (copying irrelevant steps in a process), two common human behaviors that are rare in chimpanzees. Humans violate the assumptions of the economic choice model in ways that help explain our success as a species in many environments. The extension (not demolition) of the model to selectively incorporate the distinguishing features of human behavior – sharing rewards, punishing norm violators, respecting ownership, and conforming – could enrich economics analysis and make economics more compelling for students.