Being able to recognise words visually when learning to read is affected by different genes to those used to sound out words, according to new Australian research.

The results are a breakthrough in understanding how reading is learned, and will bring further insight to the phonics debate.

Researchers also found that reading and spelling have a common genetic basis, meaning that if a child is having difficulty spelling they will be likely to struggle to learn to read.

The study results was launched at the University of Melbourne’s Education Resource Centre library on Wednesday 20 September where young twins demonstrated their reading skills with their parents.

Associate Professor Anne Castles, from the University of Melbourne’s School of Behavioural Science, along with researchers at the Queensland Institute of Medical Research and Macquarie University, tested different genetic models for reading and spelling, the first study to look at the two together.

Sets of identical twins were compared with non-identical twins to confirm that differences in reading ability are substantially due to genetic effects combined with personal experiences.

“It’s about 50-50 in terms of influence,” Associate Professor Castles says.

Further research found that distinct sets of genes affect the ability to learn the rules for sounding out written words, and that these are different from the genes that are associated with learning to read words by sight.

“For example children learning to read might be able to sound out the character ‘Dumbledore’ from Harry Potter books, but might have trouble reading words like ‘yacht’ because they don’t follow phonics rules,” Associate Professor Castles says. “This is evident in different subtypes of dyslexia.”

The research team also found that reading and spelling have a common genetic basis.

“This is the first study to put reading and spelling together in genetic models, and it showed the same sets of genes seem to be involved in learning both these skills,” Associate Professor Castles says.

“However, individuals may still show different strengths and weaknesses in reading and spelling due to their particular personal experiences.

“Environmental factors still have a big impact on reading and spelling ability.”

Associate Professor Castles says the research has implications for future research into reading and spelling.

“The existence of different reading subskills, with different genetic bases, needs to be reflected in our theories of reading and its acquisition.

Associate Professor Castles said further research would focus on exploring the nature of genetic influences on learning to read.

“These genetic factors may reflect the influence of more basic processes such as memory and language in learning to read and spell, so we need to track the causal pathway all the way through from genes to literacy.”