In a groundbreaking experiment spanning 125 countries, researchers asked a simple question to more than 100,000 people: Would you forgo personal gain to help fight climate change? The answer—delivered across 92% of the world's adult population—challenges our deepest assumptions about human nature. Nearly seven in ten chose cooperation.
The study, "Homo cooperans: Understanding the nature of human cooperation," published in Science, is the first to measure willingness to cooperate on a globally representative scale. The researchers, led by Prof. Dr. Armin Falk at the University of Bonn, set up identical decision experiments in each country. Participants faced a choice: take a guaranteed $100 for yourself, or accept $70 but trigger a $400 donation to combat climate change—but only if another anonymous stranger from your country made the same choice independently.
This is not a theoretical exercise. The design captures a genuine social dilemma that mirrors real-world challenges: functioning institutions, clean air, public safety, and a stable climate all depend on people willing to prioritize the common good over private advantage. "Cooperation is a fundamental prerequisite for societal well-being," the researchers note. Yet the factors driving human cooperation have remained poorly understood—until now.
The headline result is striking: 69% of participants chose cooperation. But beneath that global figure lies something equally important. The study reveals that individual traits predict cooperation with remarkable consistency. Those who believe others will cooperate are far more likely to cooperate themselves. Altruism, patience, and risk-taking appetite all boost the impulse to contribute. Higher education correlates with greater willingness to cooperate. Surprisingly, the researchers found no meaningful difference between men and women, and age had no effect—suggesting cooperation transcends the demographic divides that often fragment societies.
Yet culture matters profoundly. The same behavioral model explains cooperation across all 125 countries, but the strength of each factor varies widely. In Finland, people's beliefs about others' cooperation heavily influence their own choices. In Egypt, that influence is much smaller. These differences, the researchers argue, are rooted in historical contexts and cultural values—cooperation is not merely an individual trait but something shaped by where and how we live.
Perhaps most telling is what the data reveal about our blind spots. While 69% of people actually chose to cooperate, respondents estimated far lower levels of cooperation among their fellow citizens. We live surrounded by cooperators yet convinced we are surrounded by selfish actors. This pessimism—a systematic underestimation of others' goodwill—has real consequences. It can dampen our own willingness to contribute when we wrongly believe others won't.
The implications ripple outward. If cooperation is indeed this widespread, the barriers to tackling shared challenges may be less about human nature and more about signaling and visibility. When people see evidence that others cooperate, they cooperate more readily. The study suggests that societies underestimating their own capacity for collective action may be missing a crucial wellspring of potential—one that spans continents and cultures, waiting to be activated by clarity and trust.