The ACE survey, created by researchers Vincent Felitti and Robert Anda, measures a range of traumatic events that children may encounter, including physical, emotional, or sexual abuse, neglect, household dysfunction (such as substance abuse or domestic violence), or parental separation. These experiences can have profound and long-lasting effects on children’s physical health, mental well-being, and future life outcomes. In How Children Succeed, Tough explores the impact of ACEs on children’s development and argues that addressing the stress caused by these early adversities is essential for promoting resilience and success later in life.

This term, introduced by Bruce McEwen, a neuroendocrinologist at Rockefeller University, refers to the cumulative physiological burden on the body resulting from chronic exposure to stressors. When individuals encounter stress, their bodies activate the stress response system, including the release of stress hormones like cortisol, to help cope with the perceived threat. However, repeated or prolonged stress can lead to dysregulation of the body’s stress response mechanisms, contributing to allostatic load. Tough explores how chronic stress and high allostatic load, often stemming from adverse childhood experiences and toxic stress environments, can impair children’s physical health, cognitive development, and socioemotional well-being.