Tools of the Mind is an early childhood curriculum based on the principles of cultural-historical psychology. The program was originally developed and pilot tested in Denver, Colorado, in the 1990s and since then has expanded to many other states and is currently serving over 30,000 children ages 3–6. The main goal of the program is to help children learn how to become – in Vygotsky’s words – ... [Show full abstract] “masters of their own behavior.” To accomplish this, Tools of the Mind engages young children in activities that promote their social, emotional, and cognitive self-regulation. Mature intentional make-believe play is one of the hallmarks of the program, and special instructional strategies are employed to scaffold play in children who enter preschool or kindergarten lacking mature play skills. In addition to supporting play, Tools teachers engage children in a variety of other activities and games that have children acquire early academic skills while at the same time practicing other-regulation and self-regulation.