Regular Bedtimes Are Better for Young Minds
BY Elizabeth Landau | 8/2/2013, 1:42 p.m.
(CNN) -- If your children are throwing temper tantrums because sleep seems unappealing, consider that it may be okay to let them stay up a little longer, as long as bedtime happens around the same time every night.
A new study suggests that consistency of young children’s bedtime is associated with positive performance on a variety of intellectual tests. The study was published in the Journal of Epidemiology and Community Health.
“If the child prefers to go to sleep a little bit later, but it’s done regularly, that’s still okay for them, according to the evidence,” said Amanda Sacker, professor in the Department of Epidemiology and Public Health and University College London.
Researchers looked at information about betimes and standardized test scores for more than 11,000 children who were part of the UK millennium Cohort Study, a nationally representative study of children in the United Kingdom.
The Millennium Cohort Study followed children when they were aged 3, 5, and 7, and included regular surveys and home visits. Researchers asked parents about family routines such as bedtimes.
Children also took standardized tests in math, reading and spatial abilities when they were 7 years old.
Researchers controlled for socioeconomic status in addition to other factors such as discipline strategies, reading to children and breakfast routines.
The study found that, in general, consistent bedtimes were linked to better performance across all subject areas. This was especially true for 7-year-old girls, regardless of socioeconomic background. They tended to do worse on all three intellect measurements if they had irregular bedtimes. Boys in this age group did not show the effect.
In both girls and boys, non-regular bedtimes at age 3 were linked with lower test scores, but not at age 5.
Bedtimes that had never been consistent for girls at ages 3, 5, and 7 were associated with lower scores than regular bedtimes. For any two of these ages, boys also tended to do worse on the tests if they didn’t go to sleep at a routine time.
These results “showed that it wasn’t going to bed late that was affecting child’s development, it was the irregular bedtimes that were linked to poorer development scores,” Sacker said.
Why did girls appear bo be more strongly affected by irregular bedtimes than boys? “It might be that girls are more susceptible to elements of the psychosocial environment than boys, and hence also more easily perturbed by inconsistent bedtime schedules,” the study authors wrote.
Sacker and colleagues had initially suspected that late bedtimes would also be associated with poor cognitive test performance, but this turned out to not matter when other factors such as socioeconomic status were controlled for.
Researchers found that, in general, children who had irregular bedtimes or went to bed after 9 p.m. tended to come from lower socioeconomic backgrounds than other study participants. These were the children more likely to be from poor homes and have mothers with poorer mental health. They were also less likely to have breakfast and be read to daily.