Are some kids burning out, peaking early by the time they get into college?

The Harvard blogger I referenced is a big advocate of “specializing” in high school by finding one thing that you do very well and do a deep dive into mastering it. There used to be a time not long ago where HS students were encouraged to try different things and be well-rounded academically, in the arts, athletically, and socially. I worry about what kind of 13-17yo kids we are mass producing where if they don’t specialize (e.g. excel in computer programming) by the time they graduate from HS, they are perceived as being several steps behind their peers?