According to a 2007 New York Times article, by the time young children turn six years old, their bodies have chosen a preference to rise early or stay up late. The night owls, of course, have increased difficulty rising in the morning, since this goes against their body clock. Most school-aged children need 10 to 11 hours of sleep each night, although this can vary, depending on each child's natural body rhythm and needs. Some children naturally fall asleep earlier than others.
Children need to get the proper amount of sleep because that's when some very important brain functions occur. Sleep encourages the brain to develop new connections between nerve cells. One study showed that one missed hour of sleep per night for three nights can cause a child to perform at two grade levels below his actual grade level. The children with sleep loss showed slower brain waves, had trouble recalling what they learned and performed poorly on tests, leading to poor grades. Sleep deprivation can even lead to lower I.Q. scores.
Chronic sleep loss can cause physical illness, including heart disease. Lack of sleep can increase allergies, hearing problems and ear infections. At least one study showed that children who get too little sleep are prone to weight gain. Sleep loss may effect insulin production, increasing the chance of the child developing diabetes.
A sleep-deprived child will be drowsy in the morning, but as the day progresses, he becomes more active and less able to focus and concentrate in school. The more tired a child gets, the more wound up he becomes, making it increasingly difficult for him to fall asleep. Because he doesn't appear to be tired, parents may not realize how much sleep he is missing at night. Children who aren't getting enough sleep might be more likely to misbehave, more prone to "act out" and exhibit non-compliant behavior, have more trouble getting along with their peers and show more aggression. Sleep-deprived children are also more accident-prone.
Psychiatric problems can also arise in elementary children who are not getting enough sleep. Children exhibited signs of anxiousness, aggression or depression, which made it even more difficult for them to fall asleep and sleep through the night. This can become a cycle of sleep-deprivation that would be hard to break and could lead to sleep problems in adulthood.