The Upside of Stress

How Your Beliefs About Stress Change Its Effects

For years, health psychologist Kelly McGonigal operated under a single directive: stress is toxic. She crusaded against it, telling audiences it kills brain cells and damages DNA. Her advice was always to reduce stress and avoid pressure. But a single scientific discovery forced her to realize this well-intentioned message might have been doing more harm than good. A massive study of thirty thousand adults revealed that while high levels of stress did increase the risk of dying by 43 percent, this was only true for people who believed stress was harming their health. Those who experienced high stress but did not view it as dangerous had the lowest risk of death in the entire study. It was not the stress itself that was the problem; it was the belief that stress is the enemy.

This finding highlights the power of mindset science. A mindset is a core belief that acts like a filter for reality, shaping everything from physical strength to long-term health. By changing a single mindset, we can trigger a chain reaction that alters our biological responses. In one demonstration, McGonigal resisted as psychologist Alia Crum tried to push her arm down; her arm eventually gave out. When Crum asked her to instead imagine reaching for something she cared about, McGonigal felt a surge of strength that made her arm immovable. The shift in focus transformed its physical effect.

The power of these mental filters appears in many contexts. When hotel housekeepers were told their daily labor met the surgeon general’s requirements for exercise, their bodies responded to this new perception without any change in behavior. They lost weight, their blood pressure dropped, and they enjoyed their jobs more. Similarly, when people drank a milkshake they believed was an "indulgent" treat, their levels of ghrelin—the hunger hormone—dropped three times as much as when they thought they were drinking a "sensible" diet shake. Though the shakes were identical, the body’s hormonal response was dictated by the label.

This biological flexibility is especially critical for stress. When we view stress as an opportunity for growth, our bodies produce more DHEA, a neurosteroid that helps the brain grow and recover. This "growth index" predicts better focus and resilience. Our mindsets also have a measurable impact on how long we live. Research shows that people with a positive view of aging live an average of eight years longer than those who hold negative stereotypes. Our relationship with stress follows this same pattern, where perspective dictates the outcome.

The most significant difference between mindsets is how they drive our actions. A "stress-is-harmful" mindset leads to avoidance, where we try to distract ourselves or escape pressure. A "stress-is-enhancing" mindset encourages us to face difficulties head-on, plan strategies, seek help, and look for meaning. This proactive approach turns the belief into a self-fulfilling prophecy. Adopting a new mindset is an "open-label" process where we consciously choose how to relate to our experiences. Stress arises whenever something we care about is at stake; because stress and meaning are linked, a purposeful life will never be pressure-free. The goal is not to eliminate stress, but to get better at it by acknowledging it, connecting it to our values, and using the energy it provides to take action.