Stronger early reading skills may predict higher intelligence later in life, according to a recent study.

Researchers from the University of Edinburgh and King's College London found that early reading skills might positively affect later intellectual abilities.

"Since reading is an ability that can be improved, our findings have implications for reading instruction," Stuart J. Ritchie, leader of the study and a research fellow in psychology at the University of Edinburgh, said in a statement. "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."

For the study, researchers looked at nearly 2,000 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.

They examined scores from tests of reading and intelligence taken when the twins were 7, 9, 10, 12, and 16. Using a statistical model, they tested whether differences in reading ability between each pair of twins were linked to later differences in intelligence, taking into account earlier differences in intelligence.

Researchers found that earlier differences in reading between the twins were linked to later differences in intelligence. Reading was associated not only with measures of verbal intelligence (such as vocabulary tests) but with measures of nonverbal intelligence as well (such as 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."

Researchers said the study may address the question of why individual children from one family can score differently on intelligence tests, despite sharing genes, socioeconomic status, and the educational level and personality of parents with their siblings.

The findings were recently published in the journal Child Development.