Giving young children regular bedtimes could help expand their brain power, a new study suggests.
Researchers have found that inconsistent bedtimes are linked to children's cognitive development and warn there could be "knock-on" health effects throughout life.
The authors wanted to test if the time a child went to bed, and the consistency of bed times, impacted on their intellectual performance, measured by testing their reading, maths and spatial awareness.
The study, published in the Journal of Epidemiology and Community Health, examined more than 10,000 children taking part in the Millennium Cohort Study - a long-term study of children born in Britain between September 2000 and January 2002.
The research was drawn from regular surveys and home visits made when the children were aged 3, 5 and 7 to record family routines, including bedtimes.