Reading ability in the US has fallen sharply in the last decade as computer use has increased.
Scientists at Sweden's University of Gothenburg analysed the differences in reading achievement from nine to ten-year-olds over time in Hungary, Italy, the US and Sweden, looking at how reading skills have changed since the 1970s.
They found that reading ability has improved steadily in Italy and Hungary - but has fallen rapidly since 1991 in both the US and Sweden.
And while the Swedish and American pupils described a large increase in the use of computers in their free time during this period, there was no similar increase in Hungary or Italy.
"Our study shows that the entry of computers into the home has contributed to changing children's habits in such a manner that their reading does not develop to the same extent as previously," says Professor Monica Rosén.
"By comparing countries over time we can see a negative correlation between change in reading achievement and change in spare time computer habits which indicates that reading ability falls as leisure use of computers increases."
She says it's not the computers themselves, or even the activities they're used for, that impair reading skills. Rather, she says, it's the way in which they have stolen time from leisure reading.
And it's the higher-ability children who seem to be affected.
"We have shown that the poorer results are principally caused by a fall in the skills of those from the centre of the ability range and upwards," says Rosén.
"It is not that case that there are more less-gifted readers or that the skills of these readers have become poorer. What has happened is that there are fewer high-performing children."