Some children grow up in homes where more than one language is spoken. Understanding two languages can help children as they grow older. However, studies showing there is a more immediate effect of bilingualism on babies’ brains.

Researchers at the University of Washington organized one of the studies. They measured brain activity to compare babies in bilingual families to those in homes where just one language was spoken. Researchers called these single language families, “monolingual” homes.

The researchers studied babies who were between six and 12 months old. The babies were not yet saying words in any language. The youngest monolingual babies were able to recognize a difference between a language used at home and another language. But by 10 to 12 months of age, the monolingual babies were not identifying the sounds of the second language -- only the main language spoken in their home.

By comparison, the bilingual babies did not differentiate sounds of different languages spoken to them between the ages of six and nine months. But between 10 and 12 months, they could identify the different sounds of both languages.

Another study has shown the effect of early education on future learning abilities. The study followed more than 1,300 children from birth through the ages of 10 or 11. It found that children who received higher-quality care before starting school had better language skills by those ages than children who had lower-quality care.