Littering Experiment Challenges Popular Theory on Bystander Intervention
A field experiment tested people's willingness to confront a stranger for littering.

Altruistic Punishment Is Unlikely to Bring about Cooperation among Strangers in Daily Life, Says NYU Abu Dhabi Expert

Press Release

A new study published in Nature Communications has shown that altruistic punishment from bystanders upholding social order does not always measure up to the “crime." Altruistic punishment is the disciplinary behavior that humans display toward strangers, when social norms are ignored or violated, independent of laws and penalties imposed by institutions such as governments and police.

Field experiments conducted by researchers from NYU Abu Dhabi, University of Innsbruck, and University of Cologne found that most people are unwilling to increase altruistic punishment if the offense is more serious mainly because they fear some kind of retaliation if they speak up.

The research was carried out at two major train stations in Cologne, Germany. Actors violated a social norm by littering in front of unsuspecting subjects. Two variations were played out: one where a violator tossed an empty coffee cup to the ground (a lesser offense) and another where a violator littered a lunch bag full of trash (a greater offense). These variations played out hundreds of times in front of different subjects while researchers watched to see what they would do.

The outcome was unexpected. The study showed that the likelihood of the bystander confronting the violator was exactly the same no matter how big or small the violation. “The seriousness of the offense increases, but the punishment does not,” said study co-author Nikos Nikiforakis, professor of economics at NYU Abu Dhabi. “Since this important condition is not observed in the field, altruistic punishment is unlikely to account for widespread cooperation among strangers in daily life. We probably need another explanation.”

Surveys conducted after the field experiment found that most subjects felt more upset with the bigger violation — the discarded lunch bag — and thought it deserved more serious punishment but weren’t willing to do it themselves because they feared it would backfire and the violator would retaliate against them. “The greater the severity of the violation, the greater was the fear that the violator might be the type of person to retaliate,” Professor Nikiforakis explained.

The study and survey results provide a potential explanation as to why governments and police have emerged to uphold social order. According to Professor Nikiforakis, these institutions handle extreme cases where bystanders are too reluctant to get involved.


Read the paper: Altruistic punishment does not increase with the severity of norm violations in the field


About NYU Abu Dhabi

NYU Abu Dhabi is the first comprehensive liberal arts and science campus in the Middle East to be operated abroad by a major American research university. NYU Abu Dhabi has integrated a highly-selective liberal arts, engineering and science curriculum with a world center for advanced research and scholarship enabling its students to succeed in an increasingly interdependent world and advance cooperation and progress on humanity’s shared challenges. NYU Abu Dhabi’s high-achieving students have come from 115 nations and speak over 115 languages. Together, NYU's campuses in New York, Abu Dhabi, and Shanghai form the backbone of a unique global university, giving faculty and students opportunities to experience varied learning environments and immersion in other cultures at one or more of the numerous study-abroad sites NYU maintains on six continents.