Quote Originally Posted by Thorne View Post
So our culture has decided that it's better to restrict alcohol to those who are old enough to metabolize it more readily, which we have defined legally as 21 years old.
Which shows another reason this distinction is arbitrary. Your "we" is the USA: here in the UK that limit is set as 18, and in other countries lower still. Similarly, there is no global agreement, even within the Western world, on the legal age for sex. In my and thir's countries sex is legal at 16, and sex between younger teens (as illustrated by the original article) is officially ignored unless older people are involved or there is evidence of coercion or bullying. So far, this has not led to the fall of civilisation.