What the Heck is Musical Head Banging?

I thought I knew what musical head banging was.  I was wrong.musical head banging 1

In 1995 I won a musical head banging contest at my niece’s bat mitzvah. As I recall the DJ played “Smells Like Teen Spirit” by Nirvana. I did what any student of 70’s hair band culture would have done. I planted my feet firmly in place, raised my right arm, saying “I Love You” in American Sign Language (cuz rock n’ roll is all about the love, dontcha know?) Then I proceeded to make like I was hammering finishing nails into a two-by-four. With my forehead. Brother Beavis will demonstrate.

I was so naive. That was NOT musical head banging.

Apparently, musical head banging has something to do with your baby’s sleep. It is claimed by some “experts” that if you play music to your baby as she falls asleep in the crib, she may develop musical head banging. And this is bad.

I learned this from illinoishomepage.net in an article entitled “Sleep Problems”


You might think letting your baby fall asleep to music is a good thing, but old habits sleep hard. It could actually negative affect their sleep.

It sounds harmless, but letting baby drift off listening to music might have a few consequences. Studies show constantly relying on certain sounds to go to sleep can create a need to listen to music.

So, if they’re away from home and don’t have access to that music, baby might not be able to sleep without listening to it first.

This could lead to musical head-banging. Music could make your child more likely to bang their head against solid objects.

If you think music isn’t the right choice for your child, experts suggest a white noise machine. It will drown out household sounds and provide a quiet environment for them to sleep in.

You can even find some apps for them on your smartphone.

A graphic in the accompanying video suggests that livestrong.com is the source of this information. I followed the lead and found this article from s2015. It states, in part,

[H]eadbanging (sic) is the habit some children have of banging their heads against solid objects. If you have a child who bangs his head, you may notice it’s more prevalent when falling asleep or when listening to music, notes the University of Michigan Health System. That means headbanging could be exacerbated when your little one listens to music to fall asleep.

I was floored. I’ve been a sleep consultant for a long time and I’ve never heard of this phenomenon before. According to her bio, the author of the piece, whom I will not name, “specializes in health, fitness and lifestyle topics. She is a support worker in the neonatal intensive care and antepartum units of her local hospital and recently became a certified group fitness instructor.” I wonder if she’s ever had a baby?

Not finished with my search, I checked the references at the bottom of the article. There was one piece that did indeed come from the University of Michigan Health System web site. The subject of the article was “Bad Habits/Annoying Behavior“. Here is what this piece had to say about head banging:

Body rocking is when (sic) a child rhythmically rocks while either sitting or resting on their knees or elbows. This behavior usually starts around age six months and disappears by age two. Most children rock for 15 minutes or less. Like head banging, it occurs while listening to music or falling asleep.

That’s it. How did we get from here to “Music could make your child more likely to bang their head against solid objects”?

I’m afraid what happened here is the internet version of a game of telephone. The message got so garbled by the last call that this television station in Illinois ended up giving some pretty dumb advice to parents.

What is Musical Head Banging, Really?

It’s one of two things. Babies rock and bang their heads sometimes when they are tired. It is a sort of self-soothing technique. It usually lasts no more than 15 minutes. Other babies bang their heads as a kind of what I call “Stupid Baby Trick”. Bonking her head makes the baby hear this hollow ‘thud’ sound that she didn’t expect. Any unexpected sensation is interesting to a baby. She’ll keep doing it because, well, it’s interesting. The same thing happens when she pulls her own hair (it HURTS!) or gags herself with her own fist.musical head banging 2

Eventually the child gets bored and the behavior stops. But sometimes the baby keeps the behavior going if it gets a big reaction from a caregiver. It is as if the baby says to herself “I’m getting bored with this head banging thing, but look what a reaction I get from mom! I’m gonna keep this going!”

Can music become a negative sleep association?

Something else the Illinois article said caught my attention. It was the suggestion that that music at bedtime might interfere with sleep: “Studies show constantly relying on certain sounds to go to sleep can create a need to listen to music (emphasis added).” What were these studies?

I went to the online National Library of Medicine/National Institutes of Health, affectionately known as “PubMed“. I performed every search I could think of combining “music” and “sleep disturbance” or “sleep associations”. I could find none. There are no such studies. Playing music in the nursery does not interfere with the process of a baby falling asleep or staying asleep. In fact, one of the sources cited at the livestrong article actively recommended music to help a baby fall asleep.

Unless of course you decide to blast “Smells Like Teen Spirit” in the nursery.

School Start Time: City Boys Matter!

Is a later school start time better for teenagers?

“Yes, of course”, you say! But how do you know that?

What if I told you that the correct answer is  “It depends”?

Does School Start Time Matter?

To answer this question, investigators at the National Institutes of Mental Health (NIMH) sent surveys to high school students, aged 13-17, all over the US. Almost 10,000 kids participated.

NIMH investigators asked questions about bedtimes, amount of sleep, and various other questions to tease out important demographic information. Weeknight bedtime was assessed with the question “What time do you usually go to bed on weeknights?” Sleep duration was assessed with the question “How many hours of sleep do you usually get on week (weekend) nights?” They asked this question to indicate whether the teenagers slept at least 8.5 hours of sleep. This number was chosen, instead of 9.5 hours, as is currently recommended, because at the time of the study, the National Sleep Foundation (NSF) recommended only 8.5 hours for teens.

Any high school kid will tell you that it’s much more complicated to understand the truth about their sleep. For this reason, the NIMH investigators asked about family characteristics, after-school jobs and extracurriculars. They also asked about school type (public vs. private, etc) and grade level.

Here’s What They Found

The NIMH school start time study is a good example of why it’s never a good idea to assume you know the answer to a question. Always investigate.


The results were surprising. Investigators found some results they expected, but many others they did not expect.school start time 2

Teenagers Don’t Sleep Enough

The average number of weeknight sleep hours was 7.71 hours (7.60 for girls and 7.81 for boys). Not only was this result almost an hour less than the recommended NSF nightly allowance, it was almost two hours less than current recommendations!

But as this number was an average, it is obvious that some teenagers slept less than 7.71 hours, and some slept more. Extra sleep was associated with some surprising findings, which we’ll get to soon.

When school started later, students went to bed later. This was one of the expected findings.  And here is where it gets interesting.

School Start Time Matters… Until 8 AM

The investigators looked at school start times and then asked how many students got adequate sleep at each starting hour (e.g., 6:30 AM, 7:00 AM, etc.) When school started later, students got more sleep and more got the recommended amount of sleep (8.5 hours), but the effect went away for start times after 8:00 AM. In other words, if school started at 8:30 AM, or 9:00 AM, the students on average did not get more sleep! There appeared to be “diminishing returns”. In other words, later school start times was good for high schooler’s sleep… up to a point, namely 8:00 AM.

It Gets More Complicated…

It turns out that the benefits of later school start times may fall to boys only. When investigators looked at boys and girls separately, they found some unexpected results. School start time was not associated with hours of sleep for girls, regardless of start time. Similarly, later start times did not correlate with girls getting their 8.5 hours of sleep. School start time just didn’t seem to have anything to do at all with girl’s sleep. school start time 3

What about the boys? Since girls’ sleep didn’t seem to be affected by school start time, you would think that when you removed girls from the analysis that the effect would be even bigger for boys.

And it was… up to a point.

When school started later, boys got more sleep, and more boys got “adequate sleep” but the effect went away after 8AM.

City Boys vs. Country Boys

It turns out that location of the school mattered quite a bit. Investigators divided the kids into three groups: major metropolitan county (census-defined metropolitan counties with ≥ 1 million residents), other urbanized county (metropolitan counties with < 1 million residents), and non-urban county (non-metropolitan counties).

For boys living in major metropolitan areas, later start time was associated with adequate sleep, but only until 8 AM. For boys living in “other urbanized counties” and non-urban counties, start time had no effect on adequate sleep. Put another way, for boys going to big-city schools, later start times were associated with better sleep (up until 8 AM, of course…) For boys in smaller cities or suburbs, start time appeared to have no effect on quality sleep.school start time 4

Once again, girls sleep was unaffected by location. City girls got just as much sleep as country girls.

Make-up Sleep

In an earlier post, we showed that teenagers tend to sleep differently on weekends. These are the days we expect teenagers to “make-up” on sleep.

It is reasonable to guess that the teens who go to high schools with later start times might not need to make up for lost sleep on weekends. Indeed this is what the NIMH investigators found at first… until they “adjusted” the results. “Adjustment” means eliminating or reducing the confounding effects of extraneous confounding factors like sex, age, etc. The NIMH investigators adjusted data for all their results in this study, but when they used adjustment to look at make-up sleep, they got an unexpected result:

There seemed to be a correlation between later start times and less make-up sleep, but the effect would go away after normalizing for age, sex, school level, and school location (city vs. country, etc). In other words, overall later school start time did not give teenagers the opportunity to make up for lost sleep.

Strengths of the Study

Large studies are always better than small studies. The statistics always get better for one thing. Put another way, you can resolve small differences, and bring out subtleties better if your study has more subjects. We believe something closer to the truth is found when you look at very large populations. Almost 10,000 high school kids is a large enough sample size to give results we can believe. And indeed this study found some interesting differences: between boys and girls, and between city boys and country boys.school start time 5

The large sample size also allowed the NIMH investigators to uncover the compelling finding about the hour of 8:00 AM: Later start times did indeed matter, but the effect would disappear after 8.

Limitations of the Study

Survey results are never the best way to arrive at the truth. Think of those times in American history when opinion polls grossly mis-calculate the outcomes of elections! The NIMH school start time study was limited by use of a cross-sectional survey as the research tool. As a result, all the investigators could tell us is that there were associations between things like school start times and hours of sleep. They were unable to tell us if any two things were causally related to each other.

Furthermore, it’s far more accurate to measure hours of sleep than it is to ask a teenager how long she slept! In a study this large, actual measurement was not possible. They also did not ask the kids about confounders like cell phone use, which may vary from group to group.

Finally, there is the question of generalizability. It is important, when reading about studies like this on the internet, to ask an important question: “Does this study apply to me?”  If this same study were performed on teenagers living in isolated villages deep in the Amazon River basin, you might justifiably say “I’m not sure this study tells me anything about my teenager’s sleep”. But you can still ask the question about studies done on American teenagers. Look carefully at the study and ask yourself how easily your child could have been one of the kids who turned in a survey.

Summary: The NIMH School Start Time Study Suggests…

  • That teenagers don’t get enough sleep
  • That later start times matter, but
    • only if you’re a boy, and
    • only if you live in a big city
    • only until 8 AM

What they’re saying about Sleep, Baby!


Cell Phones Cause Sleep Problems in Teens

Every year since 2002, the National Sleep Foundation conducts a “Sleep in America” poll. The topics vary every year. In 2011, NSF focused exclusively on the things we do in our bedrooms (you know, besides sleep).  Data from that poll continue to generate insights into how we sleep, or don’t sleep as the case may be. In 2016, investigators pulled data from the “Bedroom Poll”, looking at adolescent technology use and how it affected their sleep. The result? Cell phones cause sleep problems.

The Study

This study looked at data from 259 kids aged 13-21 years. Investigators asked the teens when they went to bed and how long they slept. They were particularly interested in the kids’ own assessment of how tired they were during the day, and whether they believed they were getting “adequate” amounts of sleep at night. Finally, all these data were compared to the amount of time the teens spent doing things on their phones.

cell phones cause sleep problems 1


The Results

The respondents slept an average of 7.3 ± 1.3 hours. The recommended amount of sleep, according to Nationwide Children’s Hospital, is 9 1/2 hours.

An astoundingly large number of respondents (97%) used some kind of technology before bed. Increased technology use and the frequency of the cell phone waking you up correlated with waking too early, waking unrefreshed, and daytime sleepiness. Teens who said their sleep was “inadequate” had shorter sleep duration, greater  technology use before bedtime, feeling unrefreshed on waking, and greater daytime sleepiness than teens reporting “adequate” sleep.

The Conclusion: Cell phones cause sleep problems for teens

I can hear parents of of teenagers reading this thinking to themselves “tell me something I don’t know!” But scientific studies like these, even though they rely on survey data, are important because they give us an idea of the magnitude of the problem.

cell phones cause sleep problems 3
Cell phones cause sleep problems? Or sleep problems cause cell phone use?

In this survey, the average teenager got 2 hours less sleep than the recommended 9 1/2 hours. I told my own teenagers about this result and they it surprised them. They guessed the reported number of hours would be less than 7 hours. I reminded them that this was the number the kids reported to adults administering a survey. The real number of hours of sleep may in fact be lower.

Which came first?

Another problem with the study is that it only describes the kids report. The study shows a correlation between cell phone use and bad sleep. It doesn’t tell us anything about causation. In other words, do cell phones cause sleep problems? Or do sleep problems cause kids to stay up and use their phones?

To answer questions like this, we need to perform a controlled trial. We would take this same group of kids and randomly divide them into two groups. One group would keep their cell phones in their bedrooms as they usually do. The other group would leave the phone in another room. At the end of some period of time, say 3 months, we’d ask the kids again about quantity and quality of their sleep.

How do you think a study like this would turn out?