When my mother was my age, she opened a kindergarten. I don't know much about her motivation or her reasons but I can see and feel that little children are energizing to be around. We know the effect that a baby has but there is a strong effect from toddlers and Pre-kindergarteners, too. When I see little children at play, I see them running, starting to run and just ending some running. I can often see elementary school students waiting for their school bus to arrive. They jiggle, they sit, they stand, they walk over there and over there and back here.
High school students have an earlier bus. Research says that is a tough hour for them. Those teens arrive at the bus stop and stand in a line. They don't talk, walk, jest or jiggle. If I walk past them, most don't look my way. If I say "Good morning", one or two may greet me back.
Inner and bodily quiet is helpful for thought and enjoyment of life but for little kids, it is not going to happen. I looked up "Why do little kids run?" and one answer is that it is part of their development process. Americans are often interested in getting ahead so there are various movements and organizations trying to show children how to meditate. The practice of sitting still and observing the mind seems easier and more valuable for older people and I think it fits them well. I say if you are older and seeking quiet perspective and reflection, get hold of "Stillness Speaks" by Eckhart Tolle. But if you are a young child, run over there and jump up and down. Then, run back and jiggle.
