A little over 50 years ago, the endocrinologist Hans Selye (1956) published The Stress of Life, summarizing his research on the physiological consequences of stress.1 Because he was working with laboratory animals, Selye conceptualized stress (or stressors) as exposures to noxious environmental stimuli, such as extreme temperatures, electric shocks, or food deprivation. He identified three stages of physiological reactions to noxious events: the alarm, resistance, and exhaustion stages. Further, he linked the exhaustion stage, i.e., the depletion of bodily defenses against stress, to subsequent risks of high blood pressure, heart disease, and other diseases of adaptation. This cascade of physiological reactions to stressors and their harmful consequences for physical health were later confirmed in human subjects. But population studies of the impacts of stressful experiences did not take off until psychiatrists Thomas Holmes and Richard created the