Inconsistent bedtimes for children could have "knock-on" cognitive effects later in life, a study has suggested.
A study, published in the the Journal of Epidemiology and Community Health, found that young children's brain power could be boosted by sending them to bed at regular times.
Researchers studied more than 10,000 children, drawing information from regular surveys and home visits when the children were three, five and seven to find out about routines such as bedtimes.
When children were three, nearly one in five had irregular bedtimes but that was cut to less than one in 10 when they were older.
Experts found that seven-year-old girls with irregular bedtimes had lower scores on all three aspects of intellect tested - reading, maths and spatial awareness. This effect was not seen in boys at the same age. However inconsistent bedtimes at age three were associated with lower scores for both girls and boys.
Girls who had never had regular bedtimes at all three ages had significantly lower reading, maths and spatial awareness scores than girls who had had consistent bedtimes. For boys this was the case for those having non-regular bedtimes at any two ages.
Copyright Press Association 2013