For most of the last century, America viewed bilingualism as a detriment. Experts felt that learning a second language was too big a burden for children’s delicate minds, and could result in confusion, compound learning difficulties, and stunt intellectual growth.
But about a generation ago, a different narrative emerged, viewing bilingualism as an advantage. Children who managed to master two languages developed brains that were more flexible and adept at ignoring conflicting and irrelevant information. Bilingualism was even touted as protecting the brain from the late-life degradations of dementia.