Reading to young children stimulates their development and gives them a head start when they reach school, according to researchers who have reviewed studies on the effects of reading. Apart from helping their reading, sharing a bedtime story with a child promotes their motor skills, through learning to turn the pages, and their memory. It also improves their emotional and social development.

"You can imagine if someone technologically came up with a widget that would stimulate all aspects of a two-year-old's development, everyone would want to buy it," said Professor Barry Zuckerman, of the department of paediatrics at Boston University school of medicine, who led the study.

Studies show that children who are read to from an earlier age have better language development and tend to have better language scores later in life. Getting children to grip pages with their thumb and forefinger improves their motor skills.

Most important, though, said Zuckerman, is that reading aloud is a period of shared attention and emotion between parent and child. This reinforces reading as a pleasurable activity.

"Children ultimately learn to love books because they are sharing it with someone they love," he said. The research is published in the journal Archives of Disease in Childhood.