You’ve been looking forward to a special treat all morning. As an adult, your off-site break might include a latte and scone. However, if it turns out the coffee shop is closed, you might feel deflated but able to move on with your day. To contrast with a different stage of development, imagine you are a five-year-old in Room 7 who is anticipating being first in line, a heady accomplishment promoting powerful feelings of self-efficacy. When the time comes to line up, you make your way across...

Babies learning to walk don’t compare themselves to others or say, “I’m taking way more steps than anyone else my age.” Their first steps, tentatively letting go of solid surfaces, take great courage. But with a little practice, they waddle along like small boats on a rocky sea with single-minded focus: the determination to move forward. Soon their walking turns into running. Anyone who has ever seen the pure exhilaration of a toddler running away from a parent can’t help but smile before...

“Someone pushed me, and I didn’t push back, I found a teacher,” a four-and-a-half-year-old boy proudly announces to his father at the end of the day. His excitement indicates his sense that this was a huge step forward in his development. Stopping and getting help mid-dispute demonstrates what we call self-regulation, the ability to manage feelings and respond rather than react. In a few years, he and his classmate will have learned to resolve a heated argument themselves with words....