Imagine if baseball was taught the way we teach science. Learning to play baseball doesn’t prepare you to be a baseball player — it makes you a baseball player.
How does mastery happen? For most of human history, learning in middle childhood meant apprenticeship, not school. Children learned to master skills informally inside the family, or outside the family, more formally and later. Most people were foragers or farmers, and foraging and farming children learned by helping out— they still do. Children also learned more specialized skills by becoming apprentices to master tradesmen and artisans.
Preschoolers show some of the beginnings of apprenticeship when they imitate the people around them. Anthropologists and cultural psychologists, not to mention parents, see how even very young toddlers are drawn to imitate everything that they see their elders do, from machete handling to pancake making. But while preschoolers are essentially playing at those adult skills, school-age children begin to genuinely master them. It is more work to make pancakes with a two-year-old than to just do it yourself, but by eight or nine, children can honestly contribute to a family’s economy. Apprenticeship is a kind of work as much as it is a kind of play.