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Humans are surprisingly honest when it comes to returning lost wallets

Altruism is alive and well. So is the desire to protect one’s self-image.

ByKatherine J. WuNOVA NextNOVA Next

It turns out humans are more honest about lost wallets than their peers expect them to be. Image Credit: Pawel Gaul, iStock

Ah, the lost wallet. Few inanimate objects are capable of sowing more internal conflict.

Stumble upon a forsaken folio, and your brain will quickly find itself on an ethical seesaw: While keeping the wallet comes with a clear payoff, there’s also a serious moral cost to pocketing the prize.

It’s hard to predict what someone will do when these two impulses clash, and countless extenuating circumstances can sway the outcome. But what happens when the amount of money in the wallet increases? You might think that the average human would be more tempted to keep a fatter pocketbook.

If that’s what your gut is telling you, congratulations: You’d be in agreement with the majority of people, including most professional economists.

You’d also be wrong.

At least, that’s what a new study suggests. In an unprecedented global experiment, a team of international researchers has discovered that as the amount of cash in a lost wallet increases, so does a person’s likelihood of contacting the owner. The findings, published today in the journal Science, fly in the face of economic theories that predict the predominance of self-interest, and contradict the assumptions of researchers and non-researchers alike. Nonetheless, they hold true in 38 out of 40 countries tested around the world, capturing what appears to be a nearly universal, albeit unexpected, trend.

“What this study [found] delightfully counterintuitive,” says Valerie Reyna, a psychologist and expert in human decision making at Cornell University who was not involved in the study. “It goes against what many would assume, and the logic of...many powerful economic theories. Whenever you have something like that, it’s exciting for science.”

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In the study, a globetrotting team of economists, psychologists, and 13 very intrepid research assistants planted 17,303 “lost” wallets in 355 metropolitan hubs around the world. In each case, an undercover scientist approached an employee at a bank, theatre, police station, post office, hotel, or other public institution and hurriedly handed over a wallet, claiming to have found it on the street. The researcher then hastily exited stage left, saddling their unwitting study subject with a difficult choice.

Every wallet in the study was transparent, and was stuffed with a key, a grocery list, and three business cards with a (fictitious) male name and email address, giving the employee ample opportunity to return the wallet. Some wallets came with each country’s equivalent of $13.45 in United States currency, while others had no money at all. In the United States, United Kingdom, and Poland, the researchers also distributed a third set of wallets containing $94.15—a hefty sum they nicknamed “Big Money.”


An example wallet. Each wallet belonged to a (fictitious) male software developer with a country-specific name (in this case, the United States), listed on a business card with an email address. Also in the wallet were a key, a grocery list, and cash and coins. Image Credit: Courtesy of Alain Cohn, University of Michigan

When the team looked at how often people in each country tried to reach out to the wallets’ rightful “owners” over email, stark differences emerged: While only 10 or 15 percent of wallet recipients came clean in China and Morocco, for instance, the numbers jumped close to 70 percent in Switzerland and several Nordic countries. (In the United States, citizens landed in the absolute middle of the pack, contacting the researchers about 50 percent of the time.)

While it’s not completely clear what underlies these differences, there were a few hints of what kinds of societies might encourage or discourage financial integrity. A country’s tendency to keep mum about a lost wallet is actually a decent proxy for other measures of nationwide “dishonesty,” like public corruption, smuggling, and even filing inaccurate tax forms, says study author Michel Maréchal, an economist at the University of Zürich in Switzerland.

On the other hand, people in countries that were wealthier, educated, and more politically egalitarian—as well as those that placed more cultural emphasis on individual culpability—were more likely to speak up about the wallet.

From the outset, however, the researchers were more interested in a related, but separate, question probing the data within each country: whether or not a larger sum of cash would deter people from emailing the wallet’s owner.

In situations like these, economic dogma dictates that there’s a certain point at which greed wins out. In other words, guilt has a probable price tag—and from a self-interested perspective, the more money the wallet contains, the less likely someone should be to speak up.

That’s what Cohn and his economist colleagues went in thinking. And when surveyed, most people in a pool of 279 experts and 299 members of the general public predicted the same.

But the exact opposite turned out to be true. The sweeter the pot, the more likely recipients were to try to contact the owner, topping out at an attempted return rate of 72 percent in the “Big Money” condition. This trend, which bucked economic expectation, was observed in 38 out of 40 countries tested.

“We were really surprised by how robust the effect was across countries,” says study author Alain Cohn, an economist at the University of Michigan. “It’s remarkable to observe such a consistent result.”

Of course, not all wallets were homeward bound. Post office employees, for instance, were particularly unlikely to reach out, possibly because of the demands of their hectic schedules, says study author David Tannenbaum, a behavioral scientist at the University of Utah. Wallets turned into the Vatican and a couple anti-corruption bureaus also mysteriously went off the grid.

There were also two countries—Mexico and Peru—in which cash didn’t boost wallet reporting. But even here, the patterns didn’t completely reverse: Money or no, people attempted to return the wallets at roughly the same rate.

Explaining the trend was another matter entirely. The trend couldn’t be chalked up to self-consciousness, fear of penalty, or even the expectation of a bigger finder’s fee. It was even clear that participants weren’t returning the wallets after skimming off some of the cash: In the Czech Republic and Switzerland, research assistants kept up the ruse long enough to reunite with nearly 200 wallets, and found 98 to 99 percent of the money intact. (In all other cases, after being contacted over email, the researchers—still impersonating the wallet’s owner—thanked the study’s good Samaritans and told them they didn’t need the contents.)


The share of wallets in each country reported to their "owners" in each of two conditions: US $0 (No Money, orange) and US $13.45 (Money, red). Image Credit: Cohn et al. Science, 2019

One thing that did seem to make a difference, however, was pure and simple altruism. When the researchers repeated their experiment in a subset of countries with some of the wallets’ contents removed, they noticed that the presence of a key upped the number of concerned emails they received. Taking a key from a lost wallet is pointless. Returning it to the owner, however, benefits the other party exclusively—a hint that the bump in reporting reflected magnanimity.

“People are surprisingly caring about others,” Reyna says. “More caring than you would think when there’s nothing in it for them.”

It’s also noteworthy, Tannenbaum says, that this tendency toward benevolence transcended so many cultural and geographical boundaries. “This might suggest that this [impulse] is just a very basic human motivation,” he says. “We may come into this world with a prepackaged moral psychology.”

The inclination to rehome a lost wallet, however, wasn’t entirely charitable. Through a series of follow-up surveys, the team discovered another major motivation behind this seemingly selfless act: a strong aversion to coming off as a thief—one that increased with the amount of money packed into the wallet.

There’s a little bit of irony in this, Reyna points out. Strictly speaking, she says, “a thief is a thief for $10, and a thief for $1000.” Nonetheless, the more money the wallet contained, the more crooked people felt about pocketing it.


To test the limits of human integrity, researchers planted more than 17,000 "lost" wallets in 40 countries around the world. Image Credit: spukkato, iStock

Compared to altruism, preserving a positive self-image is probably a more subtle driving force—one that might not often occur to people when they’re attributing intention to others, explains Uma Karmarkar, a decision neuroscientist at the University of California San Diego who was not involved in the study. “It’s easier to focus on other people’s desires...and more difficult to imagine the social pressures they might face,” she says. This, she adds, could help explain why the predictions made by study participants were so off base.

Not wanting to sully your identity doesn’t sound quite as noble as worrying about someone else’s wellbeing. But the study’s findings aren’t necessarily cynical, Tannenbaum says. “It feels more positive if it’s all driven by altruism...But if we still have these concerns where we don’t want to see ourselves as bad people, that’s still a positive. We’re better off with people having those motivations than not.”

There’s no guarantee the implications of these results will translate into other ethically fraught scenarios—or even to a slightly altered (and more experimentally challenging) situation in which wallets were dropped on sidewalks, rather than entrusted to employees in a professional setting, Karmarkar points out. But there’s no denying the importance of a field study, conducted outside the artificial environment of a research laboratory. It is, after all, a unique opportunity to observe humans in the wild, behaving as they otherwise would. Even if vanity sneaks its way in, when push comes to shove, people often will do the right thing. And sometimes, that’s enough.

“I think there’s a lot of room for optimism,” Karmarkar says. “The study shows that the social norms we have decided are important for our society hold up reasonably well under duress. And that’s reassuring.”

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