What Papua New Guinea Teaches Us About Fairness
In the highlands of Papua New Guinea, an economic game reveals a surprising truth about human nature.
For decades, traditional economics was built on a simple, powerful assumption: humans are fundamentally selfish. The hypothetical Homo economicus always acts to maximize his own gain. Yet, from the bustling markets of global capitals to the remote villages of Papua New Guinea, real human behavior tells a more complex and fascinating story. Why do we leave tips at restaurants we'll never revisit? Why do we donate to charity? Why do we often choose fairness, even at a personal cost?
This article explores these questions through the lens of experimental economics, a field that tests economic principles in real-world settings. By taking simple economic games to the island of Papua New Guinea (PNG), researchers have uncovered profound insights into the forces that shape our sense of fairness, trust, and cooperation, challenging the very foundations of what we thought we knew about self-interest 6 .
Humans demonstrate concern for others' outcomes, not just their own
Fairness norms vary across societies, challenging universal models
To study complex social behaviors, scientists use standardized experimental games that create microcosms of economic decision-making. These games measure how people act when faced with choices about sharing resources and trusting others.
Three key games have been central to this research, and were notably deployed in a 2018 study on Ahus Island, PNG 2 :
This game involves two players. Player A is given a sum of money and can choose to send any portion of it to an anonymous Player B. The amount sent is tripled by the experimenter. Player B then decides how much of this now-larger sum to send back to Player A.
The amount Player A sends is considered a measure of trust, while the amount Player B returns measures trustworthiness 2 4 .
In this classic game, one player (the proposer) is given a sum of money and offers a split to another player (the responder). If the responder accepts the split, both players get the money as divided.
If the responder rejects it, both players get nothing. A rejection is a costly punishment of an offer deemed unfair, demonstrating a preference for fairness over pure self-interest 6 .
This game involves a group of players. Each can contribute money to a communal pot, which is then multiplied and distributed equally among all players, regardless of who contributed.
The game measures the tension between cooperation (contributing for the group's benefit) and free-riding (profiting from others' contributions without contributing oneself) 2 .
| Aspect of the Game | Prediction of Pure Self-Interest | Typical Observed Behavior |
|---|---|---|
| Proposer's Offer | The minimum possible amount (e.g., 1%) | A fair split, often 40-50% |
| Responder's Action | Accept any offer, as something is better than nothing | Frequently reject low offers (e.g., below 20%) |
If natural selection favors traits that enhance individual survival, why would a preference for fairness ever evolve? Biologists and economists have proposed several compelling theories to explain this paradox.
Proposed by Robert Trivers, this theory suggests that helping others is an investment in future help in return—"I'll scratch your back if you scratch mine" 3 . This "tit-for-tat" strategy can be evolutionarily stable.
This theory, advanced by researchers like Boyd and Richerson, argues that groups with more cooperative and altruistic members outcompete less cooperative groups 7 .
1971 - Robert Trivers
Helping others as investment in future reciprocity
1980s - Boyd & Richerson
Groups with cooperative norms outcompete others
1990s - Various Researchers
Prosocial values passed through social learning
Papua New Guinea provides a uniquely valuable backdrop for this research. With its immense cultural diversity—home to over 800 languages—and communities with varying degrees of integration into the global market economy, it acts as a living laboratory for studying human sociality 5 .
2018 Study by Dr. Cristian Rojas and Professor Joshua Cinner 2
The "lab-in-the-field" approach:
What does it take to run these sophisticated experiments in a remote field location? The following table details the key "reagents" in an experimental economist's toolkit.
| Research Tool | Function & Importance |
|---|---|
| Standardized Game Protocols | Pre-written, carefully translated instructions for each game (Trust, Ultimatum, Public Goods) to ensure consistency and comparability across different cultures and studies. |
| Anonymous Decision-Making Setup | Physical or digital means for players to make choices without knowing the other player's identity (e.g., private booths, numbered tokens). This prevents coercion and social shaming. |
| Real Monetary Stakes | Funds to provide participants with meaningful payouts based on their in-game decisions. This is the core of incentive-compatibility, ensuring choices have real consequences. |
| Data Collection Tools | Tablets, laptops, or paper forms to meticulously record every decision made by each player, creating the dataset for subsequent statistical analysis 2 . |
| Local Collaborators | Partnerships with local institutions and research assistants. They are essential for building trust, ensuring cultural sensitivity, and accurately translating economic concepts 5 . |
Field experiments require balancing scientific rigor with cultural sensitivity. The most successful studies adapt global research methods to local contexts without compromising experimental integrity.
These methodological innovations have allowed researchers to test economic theories across diverse societies, revealing both universal patterns and important cultural variations in human sociality.
The economic experiments conducted in places like Papua New Guinea have fundamentally reshaped our understanding of human nature. They have dethroned Homo economicus and revealed a more nuanced creature: Homo socialis—a social human driven by a complex mix of self-interest, a desire for fairness, and a capacity for trust and cooperation.
These findings are not just academic; they have real-world implications for designing policies, institutions, and businesses that foster collaboration and well-being. They remind us that our ability to cooperate—to build trust, punish unfairness, and contribute to the common good—is not a thin veneer over a selfish core, but rather a cornerstone of our humanity, forged by millions of years of genetic and cultural evolution.
The next time you witness an act of kindness or choose fairness over a small personal gain, remember that you are observing one of the most powerful and defining traits of our species.
A fundamental human trait
Deeply ingrained in human psychology
The foundation of human societies