The Irish Independent reports that a child’s sleep can impact his or her development.

A study by the American Academy of Sleep Medicine found that four-year-olds with a regular bedtime scored better in tests to assess developmental progress than those without a regular bedtime. The same children also did better in tests to assess literacy and mathematical ability. Such were the results that the researchers concluded that helping children maintain a regular bedtime was an important way for parents to help their children develop early language and literacy skills.