The genes linked with autism are thought to promote higher intelligence, scientists believe.
Genetic factors, thought to play a role in autism, are associated with heightened mental ability in people who do not have the developmental condition, a new study has revealed.
Almost 10,000 people living in Scotland had their DNA analysed, as part of the research.
They were then put through a series of intelligence tests.
Those carrying genetic variants linked to autism had slightly better test scores on average than those who did not carry the autism genes.
In addition, further evidence of the association emerged when the same tests were carried out on 921 teenagers, who were taking part in an Australian twin study.
The nature of the relationship between autism and intelligence is not clear, said the researchers.
Although up to 70 per cent of people with autism have a mental disability, some individuals with the disorder can exhibit higher than average non-verbal intelligence.