We Trust Strangers, Even When It Doesn’t Make Sense to Do So

Relationships, businesses, governments—almost every interaction people have is built on trust. eBay can’t survive without it. But why do we put so much faith in others? What makes us so sure that the person who puts a mint condition baby carriage up for sale a) Actually owns the carriage, b) Isn’t lying when he says it’s in mint condition, and c) will send the said carriage when you pay him?

David Dunning, a psychology professor at Cornell University and his colleagues, say that all rational behavior theories predict that people shouldn’t trust complete strangers. We have no way of knowing that the other person will do what he promises in any transaction, because we know nothing about that person. Any rational model of behavior predicts that the other person will renege on any promise as soon as it’s in his best interest to do so. Survival of the fittest and all.

But in a series of trust experiments with 645 undergraduates, the scientists found that 62% would give away a small sum of money even if their two options were that the other person would keep it all, or, if the person decided to return it, that both would get back a larger amount. If the students were actually calculating the odds of getting their money back or increasing it, only 20% would have taken the gamble.

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What does that tell us about ourselves? That we’re more of a society than we thought. Most of the participants talked about politeness and rudeness as motivating them to trust their fellow study subject, even if it meant potentially getting exploited by them. “Their behavior was a comment on the other person’s character,” says Dunning. By not giving up the money, in other words, the volunteers were concerned that they would be implying that the other subject was untrustworthy and a crook, because by keeping the money, they had decided it wasn’t going to be returned. “People feel a social duty to respect the other person,” says Dunning.

How does he know that the first person wasn’t simply acting out of greed over potentially quadrupling their payoff? Through other variations of this game, in which participants chose between trusting a stranger to return the money or a coin flip that would decide, people did not take such gambles on getting their money back if they were told the coin flip would determine whether they got their money back. “That tells us that people are responding to issues in the other person’s character,” says Dunning. “The signal they are sending is that ‘I respect your character.’ As soon as you take out that issue, people gamble at the rate that would be consistent with greed.”

You can interpret that as either being a sign of solidarity, an inexplicable sense of belonging to and being a member of a community in which everyone treats everyone with respect, or you can view it in a slightly more cynical way – that people trust others because they think they have to, and are guilted into acting in the more magnanimous way. Different people may justify their behavior in different ways, says Dunning. That’s because although most people will act in the more generous, way that shows respect and trust for their fellow man, that doesn’t mean that they believe internally that everyone is trustworthy. “The situation causes internal conflict,” he says. “We get 30% to 40% of people saying something like the odds are that I am going to get screwed, or not get the money back, but they still give up the $5 to the other person.”

That strength of community norms, or an obligation to act in ways that may be counter to their internal beliefs, is something that Dunning hopes to explore further. Does it come from an even deeper faith in the goodness of the world and an optimism that people are good and nice to each other? Perhaps. For now, it’s enough to know that even strangers tend to trust one another – even if it’s driven by a sense of obligation.