Is there such a thing as a reading gene? Academics around the world think not.
They believe children's ability to read is determined by a combination of genetics and their home and school environment.
Studies suggest that children with learning difficulties are five times more likely to come from a family with a history of reading difficulties.
But while researchers have ruled out the existence of a single reading gene, they believe the location of certain genes on particular chromosomes may cause dyslexia, or more subtle reading problems, in the wider population.
Studies published in the Journal of Research in Reading show that while literacy problems often run in families they are influenced by attitudes as well as genetics.
Identical twins, who can expect to have similar reading abilities, may show disparities in performance if, for example, they have different teachers at some point in their school life, or one suffers an illness.
One report, from Griffin university in Queensland, Australia, found a greater proportion of children from families with a history of reading difficulties performed below expectations than those whose parents were proficient readers.
Children's reading skills were also influenced by whether books were available at home and time was made to read.
Youngsters' beliefs in their own abilities, as well as their attitudes towards books, were also crucial.
The older children became, the more attitudes towards reading were influenced by their abilities. Those with difficulties were therefore less likely to enjoy books.
The study said: "Knowledge of family history and children's attitudes and perceptions towards reading provides important information when evaluating reading skills among early adolescents."
Kate Nation, of Oxford university's department of experimental psychology, said: "Family similarity may reflect factors such as the availability of good nutrition, adequate schooling and opportunity for reading, rather than any genetic influence.
"If a child has a reading disorder, this does not mean that he or she is predetermined to fail to learn to read. Nor does it mean that intervention and teaching are wasted efforts. General factors should be seen as placing children at risk of reading difficulties.
"An important goal for future work that has clear educational implications is to identify those genetic and environmental factors that place a child at risk of developing a reading problem, or protect them against this risk."
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Journal of Research in Reading published by Blackwell for the United Kingdom Literacy Association, ISSN 0141-0423