Some 20 years ago, a researcher (Michelle Lampl) discovered that children sometimes actually, literally, do grow overnight, sometimes as much as a half an inch, confirming what parents occasionally report. As amazing as those findings were, I wonder if her study has been replicated in any way, and if her discovery has become part of the accepted wisdom or has been undercut. I can’t seem to find out, but maybe some Dopers who have better Google-fu than I can do so. Or maybe someone knows?
I thought we all were taller in the morning due to some sort of muscular-skeletal relaxation in the spinal chord. I can’t image children growing overnight, well, I mean they’re growing all the time, but certainly nothing measurable over 12 hours. I find that impossible to believe.
Just for documentation, the research mentioned in the OP was reported in the Parenting article “Kids Do Grow Overnight” (April 1997).
I’ll agree that it sure seems impossible.
But Wikipedia reports that bamboo has been known to grow an entire meter in 24 hours. That’s an average of 2/3 of a millimeter per MINUTE! You can almost watch it grow with your eyes! Granted that that’s an exceptional rate, but even under normal conditions it can grow 10 cm in a day. That’s still 4 mm in an hour. Damn fast for growth of a living organism, in my opinion.
So, to say that a well-fed child might grow as much as 10-12 mm in a day? It would weird me out, but that’s what I came to this thread to find evidence of. Maybe it really can happen!
Specifically, the research was M. Lampl, et al., Saltation and Stasis: A Model of Human Growth, 258 Science 801 (Oct. 30, 1992). The researchers reported growth bursts of 0.5 to 2.5 cm during intervals separated by no measurable growth. It looks like there was some more research on this in the 1990s, with some researchers replicating their results and others failing to do so. I don’t know the current status of thinking on this. The necessary measurements are very difficult, so it’s always a possibility that these results are an artifact of measurement error, although the researchers asserted that they had taken precautions to avoid this.
I was hoping there was something more scholarly out there that I’d missed when I searched. Thanks, jbaker.
an anecdote:
I once grew overnight.
When I was a 12 year old boy, I got the flu and a fever, and stayed in bed for 1-2 days. When I finally strong enough to get out of bed and walk downstairs, I had grown about a half inch. My family kept a line of pencil marks on the kitchen wall tracking the heights of each kid, and by coincidence, we had marked my height just the day before I got sick. So, with a quick check on the wall, a new pencil mark was added.
Being half an inch taller after a night’s sleep isn’t very remarkable, many people can do that, or be measured even taller than that for much of their lives. I think you’d have to do a lot of skeletal measurements that might be impractical to consider this at all. It might be more significant to measure height differences over several days to detemine if there is any kind of spurt. I don’t think anyone doubts that growth rate will vary over time.
We’re all a half inch taller after getting out of bed. Google it.
ETA: Yeah, what TriPolar said.
Yeah, that. But what if you measured several consistent times during the day?
At wake up, mid day, evening, last minute before bed.
Then you could account for daily normal variance and look for abnormalities in growth rates.
Sure would be a pain to actually do, though.
Reminds me of one of the funniest things ever said in a thread I started.
How do you measure how tall someone is that precisely? You’d have check every vertebrae and leg bone length from hip to ankle, and I don’t know what your ankle can add or your feet depending on posture. You might get some idea from measuring the leg bones, if that’s where somebody happens to be growing that day (which seems likely in a growth spurt).
Damn good question. Laser rangefinders off the top of the head?
Leg bone growth really does seem indicative.
Maybe electronic transponders could be installed.
Except not in children… hm. Yeah, it’s tricky.
The researchers used a specially designed infant measuring board during home visits.
“The infant measuring board was specially designed
after the Harpenden-Holtain infant length
board (10), equipped with a fixed headboard and
mobile footboard. One observer fixes the infant’s
head as the second applies gentle pressure to the
body to ensure that the legs are straight and the
ankles are at right angles. The footboard is
brought into firm contact with the subject’s feet. A
final check on the proper alignment of the head
and body is made before length assessment.
Ninety percent of the measurements were taken
within 3 hours of the same time on each visit to
control for diurnal variation. Replicate examinations
were conducted within 1 hour, and the
observer and recorder were the same for each
replicate.”
That doesn’t seem very reliable. You can’t check the spine very well if the kid is lying on his back. Way too many variables in there if they aren’t actually measuring bones or the joints.
That’s what we have statistics for.
When the kids start doing some sort of gymnastics or throwing sport, their neck becomes stronger and may overnight return to a good posture.
Trying to measure height or length is a silly way to decide if someone has grown over a short period of time.
I’m surprised any researchers were stupid enough to attempt it or attach any significance to such measurements as an indication of “growth.”
The only “growth” relating to height anyone really cares about is long bone growth, or growth in baseline measurements of the vertebral column elements.
No; it’s not possible to grow measurably–i.e., a half inch–overnight in any real sense of the term. You may or may not lengthen overnight (due, for example, to expansion of intravertebral disks or posture changes), but that’s not a growth spurt.
I offer myself as anecdotal evidence.
All of the friends I grew up with tell me about the summer I “grew”.
When I came back from summer vacation that year, I was obviously much taller, to everyone.
No, I didn’t take regular measurements or anything.
I am now 6’2". When I was around junior high school age, I guess, I was the same height as one of my friends. Now that we are both adults he’s very short, may 5’5" or so.
To be clear, are you saying it’s not possible, or that this study doesn’t prove it? Because I agree that the measuring board is fraught with user error opportunities, but I don’t think we have evidence to say it’s “not possible”. I’d like to see another study design, perhaps using imaging and measuring growth plates, before I make that kind of proclamation.