The Truth about Trust: How It Determines Success in Life, Love, Learning, and More
by David DeSteno
Hudson Street Press, 2014

When a person proposes marriage, she or he takes a leap of faith. Trust, writes psychologist DeSteno, is essential to all relationships. It bonds family and friends and guides important decisions. When a friend or partner turns out to be disloyal, the stakes can be high. So how do we know when to trust someone?

DeSteno reveals that two key traits help to determine trustworthiness: competence, whether a person appears informed and experienced, and reliability, whether a person will remain honest and dependable over time. Studies exploring competence show that children instinctively tend to prefer a knowledgeable teacher over a friendly one, and adults often elect officials who appear in control.

Reliability is harder to gauge because trust also involves predicting someone's motives or future actions. We tend to believe that future circumstances will mirror present ones, and we find it difficult to envision the circumstances that can dramatically alter behavior. This challenge comes up in every long-term relationship, including the one we have with ourselves. We believe we can stick to a diet, for example, but underestimate how easily we will give in to temptation after a difficult day. To plan for tough times, DeSteno advocates being realistic, honest, and forgiving with yourself and others.

What about trusting strangers? DeSteno believes that an innate trust barometer kicks in. His research shows that subtle, nonverbal cues, such as crossing arms, leaning away or touching your face, can signal whether a person is deceitful.

Unfortunately, DeSteno does not present brain-level explanations of trust; he asserts instead that neuroscience is not yet sophisticated enough to tell us anything meaningful about the trait. Yet he does an excellent job presenting evidence and deriving practical conclusions for how trust works in everyday life.

Trust may be a gamble, but what is worse than being disappointed is closing ourselves off to potentially meaningful relationships. That, he says, is not a risk worth taking.