Carried out by researchers at Vanderbilt University, the new study looked at 48 children aged three to four years old from Austin, Texas. 

The children were asked to listen to an adult reading them two books about animals, which were matched for their content and complexity, but had different amounts of causal information in the story: while one book explained why animals behave and look the way they do, the other simply described animals' features and behaviors

Afterwards, the children were asked to say which book they preferred.

The findings, published in Frontiers in Psychology, showed that during the readings, the children appeared to be equally interested and enthusiastic in both of the books and understood both to the same degree.

However, when they specifically expressed a preference for a book, they tended to choose the book filled with causal information, which reveals or explains how and why things work as they do.

"We believe this result may be due to children's natural desire to learn about how the world works," explains researcher Margaret Shavlik.

"There has been a lot of research on children's interest in causality, but these studies almost always take place in a research lab using highly contrived procedures and activities," continued Shavli. "We wanted to explore how this early interest in causal information might affect everyday activities with young children -- such as joint book reading."

Read also: Six children's books every parent should get

The researchers add that the findings could help parents choose books which boost their children's interest and motivation to learn and read, which in turn can improve their literacy and language skills in early childhood.

"If children do indeed prefer storybooks with causal explanations, adults might seek out more causally rich books to read with children -- which might in turn increase the child's motivation to read together, making it easier to foster early literacy," said Shavlik.