Bedtime Stories

Research by Yvonne Kelly of University College, London, proved that the ancient wisdom, in which parents urged their children to sleep routinely at an early time, is not entirely correct. While daughters benefit from regular bedtimes, Kelly has shown that sons do not. She began her observations by viewing the connections between sleep habits and mental abilities in teens and adults around the world. Her data exemplified that sleeping schedules went hand in hand with poor academic performance. However, it was surprising to discover that not a lot of people had researched sleep habits for children under the age of 18. Thus, she and a team of colleagues began a multidisciplinary research project called the Millennium Cohort Study; an examination of bedtimes and cognitive abilities of  11,178 children. This project occurred when the children were nine months, three years, five years and seven years old. Kelly and her colleagues tested whether the children were read to before sleeping, had televisions in their bedrooms, or had a regular, set bedtime. To test their IQ’s, the children were also asked, at the ages of three, five and seven, to take standardized reading, mathematical and spatial-awareness tests. Dr Kelly’s report, just published in the Journal of Epidemiology and Community Health, shows that by the time children had reached the age of seven, not having had a regular bedtime did seem to affect their reasoning, even when other relevant variables such as bedtime reading and televisions were controlled for. But that was true only if they were female. Also, on the IQ scale, whose mean value is 100 points, girls who had had regular bedtimes scored between eight and nine points more than those who did not; however, boys were not completely unaffected. Irregular bedtimes left their IQs about six points below those of their contemporaries at the age of three. But the distinction disappeared as they grew older. We found this article important because we never knew that there was sleep a difference between the sexes. Even Dr. Kelly did not expect it and she has no explanation to offer for it.