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Do Kids Who Sleep More Have a Higher IQ?

by Sara Ipatenco, studioD

Children need sleep, and plenty of it. Sleep helps recharge a child's body so she's able to learn and play. Adequate amounts of sleep help your child maintain her good health, too. As if that's not reason enough to ensure that your child heads to bed at a reasonable hour each evening, getting plenty of sleep might also make your child smarter.

Importance of Sleep

The amount of sleep a child needs varies depending on age, but all children need sufficient sleep to enable them to function normally the next day. That means that your child needs enough sleep that she's agreeable, happy and has plenty of energy. When a child wakes up sluggish and grumpy, chances are, she's not getting enough sleep. Adequate hours of sleep each night helps promote a healthy immune system, which means that your child is less likely to get sick. Plenty of sleep also helps prevent stress and it's related effects such as high blood pressure and headache.

Sleep and IQ

IQ stands for intelligence quotient, and it's one measurement of a child's intelligence. The amount of sleep your child gets doesn't automatically predict her IQ, but it can play a role. According to an article published in "New York Magazine," getting even one hour less sleep per night than a child needs can influence academic achievement. The article notes that the performance gap between a child that gets enough sleep and a child that gets an hour less of sleep is similar to the differences between a fourth grader and a sixth grader. Sleep disorders, such as sleep apnea, have also been linked to a decrease in IQ because they negatively influence the amount of quality sleep a child gets. Sleep disorders disrupt normal sleep cycles, which reduces the amount of deep sleep a child gets, and that can result in a decrease in IQ score, according to Johns Hopkins Children's Center.

Additional Educational Impacts

Lack of sleep can cause a host of other academic problems. When a child doesn't get enough quality sleep, she'll have a more difficult time concentrating in the classroom. When she's not able to concentrate well, she won't learn the material being presented in class. Chronic lack of sleep can cause academic delays when a child falls further and further behind because she can't focus enough to catch on to the new material. Simply being sleepy at school can have similar impacts. A 2004 article published in the "Journal of Sleep Research," reports that when a child is sleepy in class, she's less likely to learn and retain the concepts being presented. If she's chronically sleepy, she can lag further behind than normal because she's failing to gain new knowledge and failing to build on previously existing knowledge.


The research suggests that not getting enough sleep can negatively impact IQ, but the opposite has not been shown to be true. Ensuring that your child gets the right amount of sleep for her can prevent a slip in IQ, but it won't raise her score. According to KidsHealth, preschoolers, elementary age children and preteens need between 10 and 12 hours of sleep a night, and teens require between 8.5 and 9.5 hours a night. Keep in mind, however, that these are averages. Your child might need more or less sleep than these averages. If your child is generally happy and productive during the day, chances are, she's getting enough sleep.

About the Author

Sara Ipatenco has taught writing, health and nutrition. She started writing in 2007 and has been published in Teaching Tolerance magazine. Ipatenco holds a bachelor's degree and a master's degree in education, both from the University of Denver.

Photo Credits

  • Thomas Northcut/Lifesize/Getty Images