Pushy parents who spend a small fortune lavishing books on their young children in the hope of giving them a head start before primary school may be wasting their time and money, according to experts.
In reality, as every child knows, the business of helping pre-school children learn their first words is surprisingly simple – repetition and familiarity. A favourite book read over and over again trumps the mini-library of children's books found in some British households. As the saying goes, less is more.
That is the view of the psychologist Jessica Horst, from Sussex University, who is presenting the latest findings from her research at the Brighton Science Festival today.
Dr Horst devised an experiment in which three-year-olds were tested to see if they would recognise and recall six new words.
The children were visited in their homes by researchers, and, during the course of a week, one group of three-year-olds were read the same story containing the new words three times. And another group were read different stories containing the same new words.
When the children were tested a week later, those who had heard just one story were much better at recalling the words than those who had had different stories read to them, according to the research, which is expected to be published in the Frontiers of Developmental Psychology journal later this year.
It found that the children who had listened to the same story being repeatedly read to them were able to learn 3.6 out of the six words on average, compared with just 2.6 words being remembered by children who had been read a variety of stories.
It is not just the number of words children learn but the difference in the rate of learning between the two groups. And, Dr Horst adds: "All of the groups who learned words, performed statistically significantly differently from chance [random guessing]"
Familiarity is the key to learning words, says the psychologist, who has spent several years studying how young children learn. The latest research builds on her previous findings that repeatedly reading the same story is more likely to lead to a child learning new words.
"In the original study, we found that children who hear the same stories again and again learn words better than the kids who get the different stories; and, in the follow-up study, I looked at how this worked over time.
"We have seen the same effect – that kids actually learn better when the information that they are not even trying to learn is repeated," said Dr Horst.
She has taken her own advice in her private life. "My son is 19 months old, but already I read the same books to him. Sometimes every single day he wants the same books," she said.
"We are showing that less is more, to a point. Obviously, the more times you read to a child and the more books you have will help them, but you don't need to go crazy and buy every single Thomas the Tank Engine book. Reading the same books over and over again helps."
The books that children – and parents – grow to know and love
The Very Hungry Caterpillar, Eric Carle
The Gruffalo, Julia Donaldson
The Tiger Who Came to Tea, Judith Kerr
The Cat in the Hat, Dr Seuss
Cinderella, Hans Christian Andersen
Winnie-the-Pooh, AA Milne