Children who are bilingual before the age of 5 are significantly more likely to stutter and to find it harder to lose their impediment compared to children who speak only one language before that age, according to research in Archives of Disease in Childhood.The researchers base their findings on 317 children who were referred for stuttering between the ages of 8 and 10.

All the children lived in Greater London, and all had started school in the UK at the age of 4 or 5. The children's parents were asked if they spoke a language other than English exclusively or combined with English at home. Just over one in five (69) of the children spoke English and a second language at home. Thirty eight had had to learn English as one or more family members did not speak English at home.

Fifteen of the 38 children spoke only one language (not English) before the age of 5, while 23 spoke their family's native language as well as English before this age.

Thirty one children stuttered in both languages.

Stuttering began at around the age of 4.5 years, and boys outnumbered girls by 4 to 1. Comparison with a group of children who didn't stutter showed that three quarters of them were exclusive speakers of a language other than English at home; only a quarter spoke two languages.

The recovery rate was also higher among children who exclusively spoke one language other than English at home. Over half of children who either spoke only their native language at home up to the age of 5, or who spoke only English (monolingual), had stopped stuttering by the age of 12, when they were reassessed.

This compares with only one in four of those children speaking two languages up to this age.

There was no difference in school performance between children who stuttered, but the authors suggest that children whose native language is not English may benefit from deferring the time when they learn it. "...this reduces the chance of starting to stutter and aids the chances of recovery later in childhood," they say.