Who Do You Believe? Inside the Science of Trust

Find out how hormones, eye contact, and past experience affect who you choose to trust.

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Who Do You Believe? Inside the Science of Trust

Can you imagine life without trust? “Jorge” can. “I could have an amazing day out with my friends and enjoy myself,” he explains pseudonymously on a web forum, “but as soon as one friend says, ‘Thanks, I had a great time,’ I start thinking, There’s no way he really had a great time. He must be saying that to make it look like we’re really friends! I’ll become utterly convinced he hates me, and I’ll be angry at him for deceiving me.”

Jorge happens to suffer from paranoid personality disorder, but other factors-including childhood abuse-can also lead to an unhealthy inability to trust. Whatever the reason, it feels miserable. “Please, someone, tell me what to do,” Jorge pleads into cyberspace. “I am willing to try anything to fix this. I can’t live like this.”

At the other end of the spectrum, people with the rare genetic disorder Williams syndrome have a natural inclination to trust too much. One American mother described on National Public Radio last year the challenge of protecting her nine-year-old, Isabelle, from strangers. “She doesn’t have that twinge of anxiety that other kids do,” said Jessica, who concealed her surname to protect her daughter’s privacy. “She won’t think, Who is this person? What should I do here? Will I be okay?”

Even for the average person, trust is a tricky game. On the one hand, it’s a prerequisite for many worthwhile things: child care, trade, co-operation, sex, friendship-even just eating out. On the other, putting your faith in the wrong place carries a high price. Trust is as risky as it is necessary.

Part 2: Why we want to trust, and can the feeling can be artificially enduced?

Part 3: The incentives helping us choose whether or not to trust.

Part 4: How a split-second impression can colour our decision to trust.

Part 5: Why chance may trump 400 year-old advice.

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Consciously or not, you probably started asking yourself these questions at an early age. Recent findings of the psychology department at Montreal’s Concordia University suggest that children as young as 14 months can differentiate between a credible and a disingenuous person. Sixty toddlers were each introduced to an adult tester holding a plastic container. “What’s in here?” the tester would query, before looking in, smiling and exclaiming, “Wow!” The subjects were then invited to take a peek for themselves. Half of them found a toy, while the other half discovered nothing but an empty container-the tester had faked them out.

Among the infants who had not been tricked, the great majority went on to follow the tester’s lead in learning a new skill. By contrast, only five of the 30 children paired with the “unreliable” adults decided to co-operate with them.

Kids and adults alike have a natural desire to trust because it releases the pleasure hormone oxytocin into the brain. This neuromodulator encourages the herding instinct that leads sheep, gazelles and other species to flock together for safety; in humans, it promotes bonding.

Seven years ago, Nature published a Swiss study that showed that inhaling oxytocin can artificially increase trust. After spraying the hormone up their noses (“three puffs per nostril,” the report specifies), the 29 subjects were willing to lend significantly higher amounts of money to strangers in a game than were their counterparts who inhaled a placebo.

Over the next couple of years, crafty entrepreneurs such as NYC-based Vero Labs started peddling Liquid Trust, an oxytocin body spray that promises to improve your dating and business life by inspiring “a strong feeling of trust” in the people around you. But before coughing up $40 for a two-week supply, take note: A 2010 experiment published in Psychological Science found that while oxytocin can influence people to feel warm and fuzzy towards someone who already appears reliable, it doesn’t make anyone gullible enough to trust someone with a bad track record.

Next: The incentives helping us choose whether or not to trust.

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On the 25th floor of a high-rise in downtown Montreal is a laboratory where computer cubicles line windowless walls. On a winter’s day in 2010, the only noise was the swivelling of chairs and the clicking of keyboards. A group of test subjects were playing a game, each person separated from the others by a curtain that prevented them from communicating through body language or facial expressions.

Upon arriving at the Centre for Interuniversity Research and Analysis of Organizations (CIRANO), the players were divided into two groups: “investors” and “trustees.” Each investor was prompted by their computer to decide whether to lend a sum of virtual money to a trustee. If yes, the money earned interest and the trustee was asked what they’d like to do with it. Ideally, they’d keep some for themselves and give the rest back to the investor along with the original sum, earning each player a small profit.

But they could also choose to pocket the full amount.

Once the trustee made their decision, the computer system told the investor how much they would be getting back-if anything-and the game started again with new pairs, chosen at random. At the end of the session, the virtual funds were converted into real-life cash. “I was quite lucky the first time I participated,” says Cristine Lachapelle, founder of Flat Broke Montreal, a blog about earning a living with odd jobs. “You got a $10 show-up fee just for walking in, which is cool, but I needed a few more bucks to go out for drinks later that night. Happily, I left with close to $40!”

While Lachapelle’s gains were the result of chance, investors in another version of the game had access to computer-generated statistics about the trustees’ past behaviour. Most of them decided to base their decisions on that data.

This strategy is logical but not foolproof, as the character known as the lieutenant colonel learns in the Dostoevsky classic The Brothers Karamazov. Responsible for safekeeping 4,500 rubles’ worth of army funds, he would illegally lend it to his friend Trifonov, who would “go to the fair, do a profitable business with the money and return the whole sum to the lieutenant colonel, bringing with it a present from the fair, as well as interest on the loan,” as Dostoevsky writes.

Everything goes smoothly until the lieutenant colonel loses his job and Trifonov brings nothing back from the fair. “Where’s the money?” asks the nervous army man, who needs to put his books in order before he turns them over to his successor.

Trifonov replies slyly, “I’ve never received any money from you, and couldn’t possibly have received any.”

This story inspired social scientist Russell Hardin to come up with a new understanding of trust. “The minimal core of a trust relationship is that there is a clear, fairly well-defined interest at stake in the continuation of the relationship,” he writes in his 2002 book Trust and Trustworthiness.

In other words, Hardin thinks it makes sense to trust someone who needs to stay on your good side indefinitely, whether it’s your significant other, your children or your work colleagues. Once the relationship ends, however, much of the other person’s incentive to behave in a trustworthy fashion is gone.

At CIRANO, the test subjects are sometimes told exactly how many rounds of Investors and Trustees they’re going to play. The reason, according to a 2011 research paper by Concordia University economist Huan Xie and her colleagues, is to see whether the investors’ trust will decrease during the last round.

So far, it hasn’t.

Next: How a split-second impression can colour our decision to trust strangers.

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Trusting someone based on your relationship or their reputation is straightforward enough. But what if you’re dealing with strangers? Taxi drivers know all about this dilemma: They have one of the most dangerous civilian jobs in Canada, with an above-average risk of being murdered, cheated, robbed or assaulted at work. They must make quick trust decisions, which isn’t as difficult as you might think.

According to researchers, 100 milliseconds of exposure to a person’s face is enough time to judge his or her trustworthiness. When you feel uneasy about someone, your amygdala fires up. Located deep within the temporal lobes, this almond-shaped set of neuron clusters appears to be connected with your memories of fearful or emotional events. But your gut reaction may not be accurate: In lab experiments, few people do more than guess whether someone is lying or not. “However, we know that a small number of people have an uncanny ability to ‘read’ deception in a complex combination of facial features,” write Oxford University social scientists Diego Gambetta and Heather Hamill in their 2005 book Streetwise, a case study about cabbies and trust. “We can’t rule out the possibility that some taxi drivers have developed special skills in this regard.” 

“The trust thing is like a ritual,” said one of the New York City drivers Gambetta and Hamill interviewed. “There’s this brief moment of eye contact between the driver and the passenger. It’s subconscious and automatic-a checking each other out. ‘I’m comfortable. You comfortable?’ And if that doesn’t work, then bang, you’re thinking, What’s this guy up to?”

To explore how trustworthy the average stranger might be, Ottawa journalist Andrea Tomkins decided to try out the “If you found a wallet on the street with cash and an ID card, what would you do?” experiment. The wallet she left at her favourite coffee shop contained a $10 bill and a note explaining that it was left there deliberately. “At the end of the experiment, the money will be donated to the Children’s Hospital of Eastern Ontario,” read the note.

The wallet didn’t last three full days, and Tomkins wasn’t sure what kind of conclusions to draw. “The problem is that this was a very unscientific study,” she wrote on her blog, A Peek Inside the Fishbowl. “We don’t know how many people saw the wallet. And all it takes is one person to ruin the outcome.”

Urged on by her readers, Tomkins repeated the experiment. This time, the wallet was still there after a week, along with plenty of thoughtful messages from those who stumbled across it, plus over $50 of extra cash donations for the hospital. “The longer the wallet remains unstolen, the more my faith is restored in humanity,” Tomkins blogged. The second wallet was stolen on day 11, with more than $100 inside.

Next: Why chance may trump 400 year-old advice.

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In spite of everything science and economics have revealed about the nature of trust and trustworthiness, there’s still no foolproof strategy for making the right decisions. Arguably the best advice was already in print some 400 years ago, in Shakespeare’s All’s Well That Ends Well: “Love all, trust a few, do wrong to none.” But a storybook ending isn’t guaranteed. As with any interesting game, trust has an element of chance.

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