I'm going to sound like an old codger here, which is a strange experience for a 28 year old, let me tell you. Bear with me, I'm not going to tell anyone to get

I'm going to sound like an old codger here, which is a strange experience for a 28 year old, let me tell you. Bear with me, I'm not going to tell anyone to get off my lawn... No, biologically people are adults at puberty. That marks a sea change where, among all sorts of other changes, people stop maturing based on time and so, from then on, primarily mature based on experience. What we're seeing here is the steady march of a feedback loop that began when the terms 'teenager' and 'adolescent' appeared. Those terms represent a meme that has changed where the dividing line between someone being a 'child' and an 'adult' lies. Before, people aged 11-19 were adults. Young, inexperienced adults, but adults nonetheless. Then teenager-hood was invented as a phase of life and the line began creeping upwards. They were no longer adults; now they were old children: not yet responsible for themselves and their actions. The feedback loop comes from removing opportunities to gain life experience: treating someone aged X like a child means that they will gain less experience and therefore mature less by age X+1. If this happens to a whole cohort, it means that people aged X+1 will start looking more like children, which will cause older generations to treat them as children. Then the cycle repeats at age X+2 in a new cohort. Apparently today, we're seeing the line creep into the early 20s.