Sixth-graders may suffer adverse effects because of the increased risk of chronic sleep deprivation, the researchers said. They also found that family stress, lower parental age and higher parental education may play a role in children’s sleep patterns.
The TAU team monitored the sleep patterns of 72 boys and 68 girls in the second, fourth and sixth grades who were mostly from two-parent middle- or upper-middle-class families.
Each child was monitored with an actigraph — a miniature wristwatch-like device that allows continuous recording for prolonged periods without interfering with rest environments. Daily logs were used to obtain subjective information from the children, and parents and children independently completed a questionnaire on sleep habits.
Results show that sleep onset time for the second-graders was more than one hour earlier than for the sixth-graders, although sleep-quality results remained stable across the studied age range. However, the sixth-graders reported more morning drowsiness than the younger children did.
These children, they said, run a greater risk of chronic sleep deprivation, which could have adverse consequences on their development.
Growth and puberty contribute to older children’s delayed sleep, but sociological reasons familiar to American children are also involved, according to lead author Sadeh.
“There are increased school demands, the need of children to feel more like adults by having a more active night life, and the incentives like late-evening or late-night TV shows and Internet surfing,” he said.
Evidence also suggests that younger parents are more likely to enforce an earlier bedtime, increasing sleep duration. However, the best predictors of sleep quality measures, according to the authors, were parents’ education and family stress.
“Although it is not entirely clear why the children of parents with a higher education level sleep better, this finding is consistent with a recent report correlating poor sleep with lower maternal education.”
They add that family stress — loss, illness, hospitalization, relocation, and emotional turmoil within the family — may lead to poor sleep in children.