 The study provides a precise charting, multi-assessment investigation, and replication of executive function development from adolescents to adulthood using for independent datasets with 23 measures from 17 tasks. Executive functions follow a canonical non-linear trajectory, with rapid and statistically significant development in late childhood to mid-adolescence, 10 to 15 years old, before stabilizing to adult levels in late adolescence, 18 to 20 years old. Age effects are well captured by domain general processes that generate reproducible developmental templates across assessments and datasets. The results provide a canonical trajectory of executive function maturation that demarcates the boundaries of adolescence and can be integrated into future studies. This article was authored by Brendan Turver Clemens, Finnegan J Calabro, Ashley Seepar, and others.