New research suggests there could be a genetic basis for some kids’ inability to pay attention at school.

A study of more than 13,000 twins from six countries found that 40 to 50 per cent of the differences in children's motivation to learn could be explained by their genetic inheritance.

"We had pretty consistent findings across these different countries with their different educational systems and different cultures. It was surprising," said Dr Stephen Petrill, professor of psychology at Ohio State University.

Before the study, researchers had assumed that the twins’ shared environment - such as family and teachers that they had in common - would be a larger factor than genetics.

But it appears that genetics and non-shared environment factors had the largest effect on learning motivation, while the shared environment had a negligible impact.

“The knee-jerk reaction is to say someone is not properly motivating the student, or the child himself is responsible,” Petrill said.

“We found that there are personality differences that people inherit that have a major impact on motivation. That doesn't mean we don't try to encourage and inspire students, but we have to deal with the reality of why they're different.”

In all the countries surveyed, students completed a measure of how much they enjoyed various academic activities. Students were then asked to rate their own ability in different subjects in school.

The researchers compared how close the answers were for fraternal twins - who share half their inherited genes, on average - with identical twins, who share all of their inherited genes.

The extent to which identical twins’ answers were matched compared to those of fraternal twins suggested a strong genetic effect.

The results don't mean there is a gene for how much children enjoy learning, Petrill said, but rather they suggest a complex process, involving many genes and gene-environment interactions that help influence children’s motivation to learn.

“We should absolutely encourage students and motivate them in the classroom. But these findings suggest the mechanisms for how we do that may be more complicated than we had previously thought,” he said.