In a study of how people in 40 countries decided to return (or not) "lost" wallets, researchers were surprised to find that - in contrast to classic economic logic - people returned the wallets holding the greater amounts of money more often. Across the globe, in 38 of the countries studied, honesty in this way increased as the incentive to cheat (higher wallet value) went up.

Honesty is important for economic development as relates to contracts and taxes for example, and for how society functions in relationships more generally. Yet, it often is in conflict with individual self-interest. Alain Cohn et al. wanted to more rigorously evaluate trade-offs between honesty and self-interest, teasing apart the motivations for the former among people handling "missing" property.

In a global field study, Cohn and an international team turned in 17,303 "lost" wallets - containing no money or the equivalent of US $13.45, or in some cases US $94.15 - to public and private institutions in 355 cities across 40 countries. Though the researchers went into the experiment expecting to find a dollar value at which participants would be inclined to keep the money, they found that in 38 of 40 countries, citizens overwhelmingly were more likely to report lost wallets with money than without. Overall across the globe, 51% of those who were handed a wallet with the smaller amount of money reported it. When the wallet contained a large sum of money, the rate of return increased to 72%.

The results, a measure of overall rates of civic honesty across the globe, offer a demonstration of how people's inclinations to show concern for others can be greater than their preferences for self, though that's not the whole story, the researchers say. People also returned the wallets with greater values because of concern for self-image. "The psychological forces--an aversion to not viewing oneself as a thief--can be stronger than the financial ones," said co-author Michel André Maréchal.

This was explored in follow-up surveys designed to better understand why honesty matters to people more than the money. As well, several additional experiments in the field - including adding a key to the wallet, which increased wallet return - confirmed that wallet returners gave wallets back both because they care about the person who lost the wallet and also because they care about their self-image.

The results, say the authors, were a surprise to both the public, who predicted returning would go down as money increased, and to professional economists. In a Perspective, Shaul Shalvi discusses how the finding rejects the classic economic logic suggesting only self-interest drives behavior. "Instead," says Shalvi, "it shows the psychological considerations of acting altruistically and wishing to do the right thing predicts people's behavior."