Do young children know that people can understand more than one language?

Can infants understand that people might be able speak more than one language, and are bilingual infants more likely to understand this than a monolingual ones? These are interesting questions, because understanding that people may speak more than one language is likely to help infants adapt more easily to their linguistic environments, and help them interact more easily with other people.

Researchers at New York University and McGill University recently explored these questions by observing how bilingual and monolingual 20 month-olds reacted to communicative situations.

Each child watched as an adult took a ball from another adult and hid it, before explaining how to find the ball – which the first adult duly found. After this, another adult came and hid the ball, but crucially they varied the language in which they explained how to find it: sometimes they used the same language as the previous adult, and sometimes they used a different language. The first adult only managed to find the ball some of time – the implication being that they only understood the instructions some of the time.

All children had been exposed to English since birth; for the bilingual children, the different language was always one to which the child had been exposed. So, while the bilingual children understood all the languages used in the experiment, the monolingual children were only familiar with English.

The researchers measured the children’s looking times when the adult searched for the ball after the second set of instructions. Looking times are a standard way of measuring infants’ reactions, because they convey surprise – the longer a child looks, the more surprised they are. So in this experiment, if the child looked for a longer when the adult had been instructed in a different language, this shows that the child was surprised and did not expect the adult to understand the instruction. In other words, they were surprised that the adult could understand more than one language.

The results showed that the monolingual children were more surprised when the researcher managed to follow instructions in two different languages compared with when both sets were in the same language, suggesting that they did not expect the researcher to be able to understand more than one language. This was the case even when the second set of instructions was given in English, which is important since it indicates that it really is the difference between languages which causes the surprise, and not the fact that the children aren’t familiar with the language in the second set of instructions themselves.

On the other hand, the bilingual children showed no difference in looking time when the researcher was given instructions in the same language or in two different languages, suggesting that they did not have any particular expectation in terms of whether the researcher would understand the instruction.

Put differently, monolingual children seem to assume that, like themselves, other people cannot understand more than one language. Bilingual children don’t seem to make assumptions about the communication abilities of other people, and therefore don’t appear to project their own linguistic experience onto others. Being exposed to another language shapes our expectations of how people interact with one another even from as young as 20 months old.

Full article: Pitts, C. E., Onishi, K. H., & Vouloumanos, A. (2015). Who can communicate with whom? Language experience affects infants’ evaluation of others as monolingual or multilingual. Cognition134, 185-192. doi:10.1016/j.cognition.2014.10.003