Children who speak their native language at home with their parents while growing up in a different country may have higher IQs, according to a new small-scale UK study.
Carried out by researchers at the University of Reading, the new study looked at 100 Turkish children aged 7 to 11 living in the UK.
The researchers asked the children to complete a non-verbal IQ test to compare those who spoke English at school and Turkish at home with those who spoke English at both school and home.
The results showed that children who spoke their native language at home and English at school scored better in the intelligence tests than those who spoke only their non-native language.
"It is easier to develop concepts at a young age in a first language and then learn a new word for it later in a different language. Children who have to learn to understand things for the first time in a less familiar language will find it much harder, so it follows that the children in our study who had done this scored lower on the IQ test," said lead author Dr Michael Daller.
"The research suggests parents can help their children develop their intelligence by encouraging them to use their native language at home, as this won't be supported at school."
The researchers added that this practice needs to be done through "meaningful communication," such as reading books and having conversations together.
Although small, the new study is not the first to show that being bilingual can have positive effects on the brain and intelligence.
A 2016 Canadian study also found that children who speak two languages are better at problem solving than monolingual children, while a study published back in 2015 which looked at 608 adult stroke patients found that those who were bilingual could be twice as likely than those who were monolingual to regain normal cognitive abilities following a stroke.
"This study was larger than most of its kind, and unusual in that it only tested children... all ... of similar ages and backgrounds. This means we can read into these results more than those of previous experiments," added Dr Daller.
"The next step is to make the study more comprehensive and see if our findings are similar with children from all backgrounds and age groups."
The findings were presented at the British Association for Applied Linguistics-Vocabulary Special Interest Group (BAAL Vocabulary SIG) Annual Conference in July 2018.