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Nurture Shock: The Lost Hour

When my daughter was younger and in the middle of a meltdown, I tried to justify her behavior to my parents by saying, “She’s really tired.”  I remember my mom telling my dad how nowadays everyone blames poor behavior on a lack of sleep.  But it turns out, according to Nurture Shock, my children’s sleep deprivation was more than just an excuse for my questionable disciplinary actions.  “Around the world, children get an hour less sleep than they did thirty years ago.  The cost: IQ points, emotional well-being, ADHD, and obesity.”


Surveys by the National Sleep Foundation indicate that “90% of American parents think their child is getting enough sleep;” however, kids don’t agree: “60% of high schoolers report extreme daytime sleepiness.”  According to studies at the University of Kentucky, “Only 5% of high school seniors average eight hours.”  And while authors Bronson and Merryman recognize some of us may remember being tired, it’s “not like today’s kids.”

The problem is that “there are as many causes for this lost hour of sleep as there are types of family.”  According to Bronson and Merryman, “Overscheduling of activities, burdensome homework, lax bedtimes, televisions and cell phones in the bedroom – they all contribute.”  But up until now, all of these reasons could be ignored because there was never really any proven cost to children.  Bronson and Merryman explain, “The surprise is not merely that sleep matters – but how much it matters, demonstrably, not just to academic performance and emotional stability, but to phenomena that we assumed to be entirely unrelated, such as the international obesity epidemic and the rise of ADHD.”

Let’s focus on the academic evidence.  Dr. Avi Sadeh of Tel Aviv University, collaborating with other scholars at Brown University, learned that “A loss of one hour of sleep is equivalent to [the loss of] two years of cognitive maturation and development.”  According to Nurture Shock, these finding are consistent with the work of other researchers’ such as Dr. Monique LeBourgeois, also at Brown, who discovered even children who shift their sleep schedule, allowing for a later bedtime on the weekend, suffer.  “Every hour of weekend shift costs a child seven points on the [IQ] test.”  Dr. Paul Suratt of the University of Virginia goes so far as to conclude, “Sleep disorders can impair children’s IQ as much as lead exposure.”

How can this be?  Well, up until the age of twenty-one years old, a child’s brain is developing.  Bronson and Merryman  explain, “Tired children can’t remember what they just learned, for instance, because neurons lose their plasticity, becoming incapable of forming the new synaptic connection necessary to encode a memory.”  Sleep loss also causes inattentiveness in the classroom because “sleep loss debilitates the body’s ability to extract glucose from the bloodstream.”

Parents, who are accustom to sleep deprivation, might wonder why their children aren’t capable of the same thing, especially if the lack of sleep means the teenagers can take on more honors classes and extracurricular activities.  According to Nurture Shock, “Kids’ sleep is qualitatively different than grownups’ sleep because children spend more than 40% of their asleep time in the slow-wave stage (which is ten times the proportion that older adults spend).  This is why a good night’s sleep is so important for long-term learning of vocabulary words, times tables, historical dates, and all other factual minutiae.”

Basically, Bronson and Merryman argue that parents need to stop thinking of the slush hour – that last hour of your child’s day when they should be in bed but they aren’t – as a chance to squeeze in one more activity.  Nurture Shock believes we need to stop treating sleep like the national debt, tacking another half-hour on to the bill every chance we get.  Instead, we need to find real strength of character and admit fatigue.  Your child’s developing brain will thank you.



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Check out Victoria Winterhalter’s other blog, Befriending Forty (, and find out what happens when the person you thought you’d be meets the person you actually became.

Victoria Winterhalter is a mother, teacher, reader, and writer on the education and environment beats for RFM. She has been with RFM since its founding in 2009 and has contributed photos and written numerous articles on education, parenting, and family travel.

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