Sleeping - Developmental Trends In Sleep

Patterns of sleep and wakefulness undergo striking changes from infancy through adolescence, but within any given age group, there is great variability. Newborns do not sleep for long stretches. Instead, they experience about seven sleep periods daily, totaling about sixteen hours. Somewhere around three months, many infants begin to sleep for at least five continuous hours during the night. Like children and adults, infants awaken briefly a few times during the night but 70 percent of one-year-olds are able to soothe themselves back to sleep. Self-comforting techniques such as thumb sucking, face stroking, and body rocking are frequent. By one year, sleep time averages twelve hours distributed into a long sleep period at night and two daytime naps.

Across early childhood, daytime naps gradually disappear, resulting in decreased daily sleep. By age four, children sleep about eleven hours per day and many have given up napping. Not only do pre-schoolers sleep less than infants, they also fall asleep differently. Young children are often reluctant to go to sleep, and bedtime rituals may take on a predictable pattern with children who have been tucked in perhaps requesting a drink of water or another good-night kiss. Children over the age of three are also more likely than younger children to depend on a favorite blanket or teddy bear to help them fall asleep.

By six to ten years of age, children are generally "good sleepers," sleeping soundly for about ten hours at night and staying alert during the day. But as they approach puberty, sleep patterns undergo further change. Studies in the United States, Europe, and elsewhere reveal an increasing tendency among adolescents to sleep less, to go to bed later, to develop different patterns of sleep on weekends and weeknights, and to report increased daytime sleepiness. But contrary to popular belief, adolescents do not necessarily need less sleep. Although optimal sleep time for adolescents is about nine hours per night, most adolescents average less than eight hours. This is unfortunate because inadequate sleep is associated with poor school performance, mood and behavioral problems, and increased risk for automobile accidents.

A study of school-age children in Israel showed that sleep habits identified in adolescents may be drifting down to younger ages. In addition, girls in the study slept more and moved less in sleep than boys, a finding that has also been observed in newborns. Overall, however, researchers have found relatively few gender differences in sleeping patterns.