It's one of those days in Ms. Mya's classroom, when things just aren't clicking: Jamilla is jumping. Ruth is running. And Reese is roaring like a great big lion for no reason at all. But Ms. Mya knows what to do. She gathers up the children, and together they begin a conversation about expectations. An expectation is something we can rely on, something we know is going to happen, says Ms. Mya. When adults guide children in a positive, proactive...