Using advanced brain-scanning technology, scientists are getting a better view of how the human brain develops than ever before. And what they’ve found is that in most people, the prefrontal cortex and its links to other regions of the brain are not fully formed until age 25—much later than anyone had realized. These areas are the seat of “executive decision making”—the parts of the brain that allow people to think through the likely consequences of an action, weigh the risks and benefits and stop themselves from acting on impulse. In other words, the stuff that makes you a mature person.

If there is an overarching theme to emerge from the science of adolescent brain development, it is that teenagers are less mature than we might have thought. This, in turn, begs the following policy question: If adolescents are less neurobiologically mature than adults, shouldn’t our policies and practices involving young people take this immaturity into account? More specifically, doesn’t the immaturity of the adolescent brain argue for added protections for young people (e.g., for disqualifying young people from exposure to the possibility of a sentence of life without the possibility of parole, or passing more stringent child labor laws) and, as well, for fewer rights (e.g., raising the driving age to 18 or returning the voting age to 21)?