Submitting... The loyalist Jamie Bryson, who is studying for a law degree. Ben Lowry says that republicans have for decades known the importance of law, and are using it to secure political, even constitutional, change It is why you cannot do things such as smoke until you are 16, vote until 18, or, in the US, drink until 21. It is why safety experts say that young drivers are more likely than older to be reckless until their mid 20s, when the part of the brain that understands of risk fully develops. When I was a teenager I was keen to get behind the wheel, and I recall being depressed to find that some insurers would not cover drivers under 30 for faster cars (which then appealed to me, but has long since not done).