The National Gallery http://lobstertube.in.net/ lobster tube For the study, researchers analyzed data on bedtimes and test scores of 11,178 7-year-old children born between September 2000 and January 2002, who participated in the U.K. Millennium Cohort Study. Mothers were asked to fill questionnaires about their child's sleeping habits at the age of 3, 5 and 7. The children were then tested on their IQ, math and reading abilities.