Is the earth round, really? It seems flat to me. I’ve been in many places in the world and I haven’t heard about anyone falling off it and so from my own logic and experience it appears the earth is flat. This is how evidence goes it seems and I find myself getting frustrated but I do try to understand the logic of disbelief– even in light of evidence. Yes, the earth is round (a sphere actually) and children with language impairment and those with other disabilities that affect language learning CAN (and do) become bilingual. No, they do not become MORE delayed.
So, what’s the logic of the disbelief. I think it goes along these lines. Children who have difficulties learning language need lots of exposure, repetition, and practice to learn language. They don’t just pick it up, and they might need certain kinds of repeated exposure in order to learn aspects of language that are particularly difficult for them. Kids who have exposure to two (or more languages) by extension have LESS exposure to both of them. So, logically it seems that they would be delayed in learning each language because they have so much less exposure to each language (for arguments sake, we could say half the exposure). So, yes I get the logic. But, they don’t get NOTHING the other half of their waking time, right? They get something. What do they get? They get language. Maybe it’s not the same language, but they do get interaction with people, opportunities to learn, concept to acquire, sounds to distinguish, listen, and imitate. In that way, the KIND of input is divided, but it’s not half the input, it’s divided by type of input. And maybe this is one reason that kids who hear divided input do not become significantly delayed in their language acquisition.
Now, in vocabulary, yes, they may appear to be delayed if we look at only one language. When children are very young (from first words to around 3) you might expect them to know about half the words (in EACH language) that their monolingual peers know. So that when you put them together, they know as many words. But, at some point they start to catch up in a way. If you look for example at the work of Bialystok and colleagues, you see that bilinguals scored lower on the PPVT (in English) than monolinguals consistently from age 3 to age 12. BUT, and this is important– their scores are still within the normal range. Monolingual scores on average are a little above the mean and bilinguals’ English-only scores on average are a little below the mean.
In our work looking at risk for LI, we also find lower scores for bilinguals on average in BOTH English and Spanish. BUT, and this is the counter-intuitive part– bilinguals were no more likely to fall in the risk group than were children who were more monolingual. In fact, children who had been bilingual the longest were LESS likely to fall in the risk group.
Well, what about kids with autism? Or with Down Syndrome? Well, yes, they can and do become bilingual. Can they learn a second language (in a sequential way?) YES!
Now, if they have a language impairment they will have it in the other language as well. It doesn’t mean they won’t struggle. But, it also doesn’t mean they will struggle MORE. And they may be better off for having learned two languages.