Begun as a summer teaching project to help inner-city youth, Breakthrough Greater Boston has blossomed into a year-round, tuition-free program that serves hundreds of kids. The program, launched by Duckworth and a colleague, was a labor of love, not for its intrinsic interest but for the difference it could make in the lives of young people who lack educational resources. The success of the project, which required long hours of tedium merely to launch, is a tribute to its value as a calling.

Codeveloped by Aaron Beck and Albert Ellis, cognitive therapy trains depressive patients to use reason and common sense to counter black-and-white thinking about their problems. Situations that seem hopelessly grim can be reframed as temporary, solvable problems; mistakes cease to be seen as devastating commentaries on a patient’s incompetence and instead are viewed as natural occurrences that everyone undergoes and everyone can handle. Cognitive therapy goes hand-in-hand with grit, since it leads to the understanding that most limitations can be overcome with effort.

Developed by researcher Brent Roberts, the corresponsive principle states that people with good work habits tend to receive good feedback that reinforces the good habits, while those with poor habits have worse experiences that induce sullenness and reinforce bad habits.