When are you actually an adult?

Most countries recognize 18 as the start of adulthood by granting various freedoms and privileges. Yet there's no exact age or moment in development that we can point to as having reached full maturity. If there's no consensus on exactly when we reach maturity, when do we actually become adults? Shannon Odell shares how scientists define adulthood using stages of brain development. [Directed by Biljana Labović, narrated by Alexandra Panzer, Gen Parton-Shin, May Yoshioka, music by Weston Fonger, Samuel Bellingham].