Our Little Lambs Grow at Night

The Boston Herald

I've long suspected that children grow when you're not looking. Years ago when mine were small, I would tuck them into bed at night and tell them to stay little. “No growing in your sleep,'' I would say when they were babies and toddlers and preschoolers, when they were young and sweet and not in a hurry to grow up.

And they would promise, each of them, “I won't grow, Mommy.'' But they did. Despite all my “stay littles,'' they grew anyway. 

I watched them all day, every day, so I knew they didn't do their growing then. Not at the kitchen table when they were eating; not in the back yard when they were playing; not at the beach or at the movies or the mall. Not anywhere I could see. Come night, every night, they seemed to be the exact size they had been in the morning. I checked: same little fingers. Same little toes. Same little arms hugging me tight.

So when did they grow up? How to explain the 9-month sleeper that was suddenly too tight? The 2-toddler snowsuit that was suddenly too short? The 6X back-to-school sweater that was never worn because somebody grew so fast one summer that she skipped over 6X? How did all three of my children leap from childhood to adolescence to full-fledged adult without my ever seeing even a bit of the process?

They grew when I wasn't looking. This was confirmed last week by scientists at the University of Wisconsin's School of Veterinary Medicine, who proved that children really do grow at night. That you put them to bed one size and they wake up a different size, like Shrinky Dinks in reverse. Scientists came to this conclusion by placing sensors on the leg bones of baby lambs and discovering that lambs do 90 percent of their growing when they are lying down.

“Almost no growth occurs when the lambs are standing or moving around,'' the study's author Norman Wilsman said. The lambs do their growing in their sleep.

As do children. 

Wilsman explained the biology behind this: The soft cartilage at the ends of bones becomes compressed when walking or standing; but when lying down, the pressure is off and the bones are free to elongate.”

So I didn't imagine this after all.

“Stay little,'' I say to my grandchildren these days. They are babies still, the boy 10 months, the girl 20 months. Neither knows what ``stay little'' means. But they like the sound of it. And the ritual.

I do, too. The words don't stop the growing, of course. But they make me notice the growth. I still don't see the actual process, only the results: the outgrown onesies; the suddenly too small socks; the blue knit sweater that doesn't fit over Adam's head anymore; the ruffled tights that used to fit Lucy perfectly and now don’t.

Children grow when we're not looking. Nature made it this way because if we saw, we'd yell, “Stop.'' We'd keep them little longer, an extra few months, an extra few years.