Kids need more, but are getting less.

• Position: Sleep

Parents who went their children to get plenty of sleep, grow up healthy, and do well in school often harbor sleep saboteurs under their roofs--sometimes in their kids' own bedrooms. John Herman, a sleep expert at The University of Texas Southwestern Medical Center at Dallas, points out that recent sleep studies have shown that watching television and working on the computer--pastimes many parents assume will quiet their offspring before bed--may rouse them instead and thus sabotage the bedtime hour. The sleep saboteurs' secret weapons, the researcher indicates, are the bright lights behind the TV set and computer screens that act as stimulants on the brain.

"Sleep researchers have known for a long time that both children and teens who follow a regular early-to-bed, early-to-rise sleep schedule perform better at learning activities than those who are not on a schedule compatible with the body's natural circadian clock," says Herman, an associate professor of psychiatry who directs the sleep lab at Children's Medical Center of Dallas. The circadian clock regulates the body's 24-hour cycle, which includes sleeping, waking, and eating. "Bright lights on television sets and computers can actually reset the circadian clock so that even small amounts can change the sleep/wake cycle so that the person goes to sleep later and thus wakes up later" Shutting down electronic stimulation at least 30 minutes before bedtime can allow sleep...