The benefits of bilingualism are well known, but a new study suggests people who speak just one language may have better judgement and insight.

Cambridge University and Anglia Ruskin found that monolinguists were far better at assessing their own performance than those who spoke two languages.

The researchers said they were surprised by their findings as bilingual people often outperform monolinguists in mental tests.

They say the finding has important implications for businessed, which may wrongly believe that applicants with more than one langauge will be superior.

Previous studies have shown that learning a second language can help build up cognitive reserve which can stave off dementia, while bilinguists are generally perceived to be more tolerant and empathetic.

But it is the first time that mental ability has been questioned. More.