Most parents nurture a secret desire that their child will grow up to be an Einstein or a Rosalind Franklin. While the market is flooded with a number of commercial products like DVDs, books, games, etc., that claim to boost a child’s intelligence, new research shows improving a most basic skill in child years will lead to development of higher IQ later on in life: reading.

"Since reading is an ability that can be improved, our findings have implications for reading instruction," Stuart J. Ritchie, lead author of the study, said in a press release. "Early remediation of reading problems might aid not only the growth of literacy, but also more general cognitive abilities that are of critical importance across the lifespan." Ritchie and his colleagues from the University of Edinburgh and King's College London conducted this research, published in the journal Child Development.

Psychologists over the years, in an attempt to understand intelligence, have divided it into two categories: fluid and crystallized intelligence. While fluid intelligence defines our problem-solving skills, crystallized intelligence is the ability to gather and retain new information, like directions to your house or the name of a country’s capital, and the ability to read and process information. It improves with age, and reading skills and vocabulary are generally a measure of this kind of intelligence.

The researchers of the current study attempted to find this correlation between early reading and improved IQ. To do so, they tracked 1,890 identical twins who were part of the Twins Early Development Study, an ongoing longitudinal study in the United Kingdom whose participants were representative of the population as a whole.

The researchers looked at the participants' scores in reading and intelligence tests taken when the twins were 7, 9, 10, 12, and 16. Using statistical models they determined if differences in reading ability between each pair of twins were linked to later differences in intelligence. Earlier differences in intelligence were also taken into account.

Since each pair of twins had the same advantage regarding genes and home environment, any intellectual differences between them had to be because of experiences that the twins didn’t share, such as a particularly effective teacher or a group of friends that encouraged reading. The researchers found that differences in reading between the twins during their childhood years affected their later differences in intelligence. Reading was associated not only with measures of verbal intelligence (vocabulary tests), but with measures of nonverbal intelligence as well (reasoning tests). The differences in reading that were linked to differences in later intelligence were present by age 7, which may indicate that even early reading skills affect intellectual development.

"If, as our results imply, reading causally influences intelligence, the implications for educators are clear," Ritchie said. "Children who don't receive enough assistance in learning to read may also be missing out on the important, intelligence-boosting properties of literacy."

The study reinforces the thought that reading is important for overall development and success in academics and life. It also provides insight into why individual children from the same family, who have the same set of genes, socioeconomic status, and the educational level and personality of parents, score differently on intelligence tests as compared to their siblings.

Source: Ritchie S, Bates T, Plomin R. Does Learning to Read Improve Intelligence? A Longitudinal Multivariate Analysis in Identical Twins From Age 7 to 16. Child Development. 2014.