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Updated: Aug 7, 2026
06:48
The HoneyComb Paradigm for Research on Collective Human Behavior
Published on: January 19, 2019
Experiments investigating cooperative types in humans: a complement to evolutionary theory and simulations
Robert Kurzban1, Daniel Houser
1Department of Psychology, University of Pennsylvania, 3720 Walnut Street, Philadelphia, PA 19104, USA. kurzban@psych.upenn.edu
Summary
Humans exhibit unique large-scale cooperation, explained by a stable mix of distinct behavioral types. Laboratory experiments reveal reciprocal individuals are most common, alongside cooperators and free-riders, maintaining population balance.
Area of Science:
- Evolutionary biology
- Behavioral economics
- Social psychology
Background:
- Human cooperation in large, non-kin groups is an evolutionary puzzle.
- Theoretical models suggest population polymorphism, not homogeneity, may explain cooperation.
- Individual differences are increasingly recognized in behavioral studies.
Purpose of the Study:
- To experimentally investigate the types of individuals contributing to human cooperation.
- To determine the stability and predictive power of identified individual types.
- To test the hypothesis of a stable, polymorphic equilibrium in human cooperative behavior.
Main Methods:
- Laboratory experiments involving decision-making in social dilemmas.
- Classification of participants into distinct behavioral types based on contributions.
- Analysis of type composition and its effect on group cooperative outcomes.
- Statistical comparison of earnings across different types.
Main Results:
- Human subjects consistently sorted into three stable types: reciprocal, cooperator, and free-rider.
- Reciprocal types, responding to others' contributions, formed the majority (63%).
- Group outcomes were predictable based on the proportion of each type.
- Despite behavioral variance, average earnings were statistically equivalent across types.
Conclusions:
- Human populations maintain a stable polymorphic equilibrium of distinct cooperative types.
- This finding supports evolutionary models predicting diversity rather than uniformity.
- Understanding individual differences is crucial for explaining large-scale human cooperation.
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