Study shows key role environment plays in developing reading skills

The findings showed that when children start out reading, both genetics and environment play a role in readings skills, depending on the skills assessed. For word and letter identification, genetics explained about one-third of the test results, while environment explained two-thirds. For vocabulary and sound awareness, it was equally split between genetics and environment. For the speed tests, it was three-quarters genetic.

But when the researchers measured growth in reading skills, environment became much more important, Petrill said.

For reading skills that are taught, such as words and letters, the environment is almost completely responsible for growth. For awareness of sounds in reading, about 80 percent of growth was explained by the environment. Speed measures were the only ones where genetics still played a large role.

"Regardless of where children start as far as reading skills, and the impact that genetics and environment had on their initial skills, we found that their environment had an impact in how fast or how slowly those reading skills developed," Petrill said.

Petrill emphasized that a child's environment is much more than just the instruction he or she receives in school. However, instruction is likely a key part of how reading skills grow over time.

Petrill said much more research needs to be done examining the roles of genetics and the environment in shaping how children learn to read.

"We believe that both factors play a role in reading, which is very similar to what researchers find in health issues such as heart disease and obesity," Petrill said. "But we know a lot more about the relative impacts of genetics and environment on the biological systems that influence heart disease than we do in reading."

For example, people can change their environment to help lower their risk of heart disease, no matter their genetic susceptibility to the disease, he said.

Petrill said he hopes we can do the same to help children improve their reading.

"Understanding the causes of why kids differ in reading skills, and the roles of genetics and environment, could help us understand how to teach them better," he said.

(Edit:Ruby)