Today, kindergarten is the new first grade with much more of the school day spent on reading readiness and learning how to add and subtract. When did play become a dirty word? "Play is important because it helps to build skills that everyone's looking for in 21st-century learning. It doesn't take away from their learning," says Kathy Hirsh-Pasek, professor of psychology at Temple. "It's more consistent with how the human brain works."