Research from the Autonomous University of Barcelona has revealed that children aged six to seven who stay up late and sleep less than nine hours per night suffer academically.
Psychologist Ramon Cladellas, who helped carry out the survey into the sleeping patterns of 142 schoolchildren, said:
"Most children sleep less than is recommended, which hinders their intellectual development because lack of sleep cannot be recovered.
"More than nine hours sleep and a nightly routine favours academic performance with pupils that sleep eight or nine hours performing worse than those who sleep nine or eleven hours."
Parents of the 65 boys and 77 girls from different schools were all asked to fill out a questionnaire, concerning their children's habits and number of hours slept per night.
The AUB team found that children who lost out on sleep had reduced communication and grammar skills, while those with irregular sleep patterns suffered poor memory and motivation.
The researchers suggested that parents attend prevention programmes to become more aware of the risks of developing poor sleeping patterns at a young age.
Cladellas added: "Children are glued to television, computers, and video games, but the same importance is not given to going to bed at the same time every night."