In the summer of 2009, shortly after the birth of his son Ellington, Paul Tough found himself in a pre-kindergarten classroom at Red Bank Primary School in New Jersey, visiting as a journalist. What struck him was the remarkable calm and orderliness of the children, despite the teacher's lack of explicit efforts to maintain discipline. These children were part of a program called Tools of the Mind, which focused not on traditional academic skills but on self-regulation—teaching children to stay focused, manage their emotions, and organize their thoughts.

This approach stood in stark contrast to the prevailing culture in preschool education at the time, characterized by a belief Tough refers to as the “cognitive hypothesis.” This hypothesis, born out of concerns raised by a 1994 report from the Carnegie Corporation, emphasized the importance of cognitive stimulation in early childhood development. It led to a proliferation of products and programs aimed at boosting children’s cognitive skills, driven by the belief that success depended primarily on intellectual abilities.

However, a growing body of evidence from economists, educators, psychologists, and neuroscientists began to challenge this hypothesis. They argued that qualities like persistence, self-control, curiosity, and grit—often referred to as