Here are some striking research findings: Children as young as 14 months can differentiate between a credible person and a deceitful one. And even as we get older, all it takes is 100 milliseconds of exposure to a person’s face for many people to judge trustworthiness or deception.

In the key relationships in our lives, trust influences whether we feel comfortable being our vulnerable, genuine selves or whether we feel defensive and guarded, anticipating harm. Trust is tricky and all-powerful, as it determines how we feel while making all kinds of decisions — accepting a dinner date, riding in a cab, heeding a doctor’s advice, hiring a babysitter, buying a certain product, or signing on with a personal trainer. We can perform these actions with ease and comfort, or with stress, fear, and anxiety — and trust makes all the difference.