Adolescent mental health refers to the psychological well-being of individuals typically aged 12-18. In The Anxious Generation, Haidt explores the rising mental health issues among adolescents, including increased rates of anxiety and depression. This term is central to the book’s examination of how modern digital environments, particularly social media, contribute to these problems.

This term, coined by developmental psychologist Alison Gopnik, describes a highly structured approach to child-rearing, where parents attempt to mold their children into specific shapes, similar to how a carpenter works with wood. Gopnik contrasts this method with gardener parenting, suggesting that the carpenter approach contributes to overprotection and limits children’s ability to develop independence and resilience.

A collective action problem occurs when individuals would all benefit from a certain action, but it has associated costs that make it unlikely for any one person to perform alone. Haidt uses this concept to explain why it is difficult for parents to limit their children’s smartphone use or encourage more free play—without broader societal support, these measures feel punitive rather than beneficial.