Edgy teen here. When humans reach certain stages of development, specific things become expected of them. Child--behave, go to school, begin to think about how you'll benefit society as an adult. Teen--behave, go to school, think more critically about how you'll benefit--or are already benefiting--society. Adult--Continue schooling and benefit society or you'll be associated with laziness and unproductiveness.
I believe this is due to the way society has developed, not how humans have evolved. Learning what to do in society is separate from evolution, as evolution is for the fittest species to reproduce, and growth of a civilization is what people as individuals have put together during their lifetimes, and then passed on to others who then further their ideals.
I believe being taught as an individual is different from a species developing an instinct.