Ministers are being urged to do more to encourage children to speak two languages from a young age.
Children brought up speaking two languages benefit intellectually
Edinburgh University and the Royal Society of Arts say research points to bilingual children being better at learning a wide range of subjects.
A new study by the university suggests children speaking two languages make no more grammatical mistakes in English than those speaking one language.
The Scottish Executive is currently consulting on its languages policy.
Professor Antonella Sorace tested a number of school-age bilingual children.
Her study echoes others which have indicated that children learning two languages may begin to talk later, but not significantly so.
Professor Sorace said bilingualism made children generally better at learning throughout their lives.
She believes parents are often put off bringing their children up bilingually because they feel it may hinder their intellectual development.
"Many parents don't know how good bilingualism can be and they think that bilingualism can cause confusion and intellectual delay in the child," Professor Sorace said.
"They deliberately refuse to speak one of the languages they could be speaking.
"By bringing them up bilingually they can give them much more than two languages."
She said a recent executive consultation document on the subject made no reference to the all-round intellectual benefits of bilingualism.
Professor Sorace said she hoped her findings would encourage parents to send their children to Gaelic schools.