Steven Pinker has written a book about languages and the basis of language development. I teach English for a living so the development of language and how people learn is of particular interest to me.
Pinker wrote a book called The Language Instinct. In a chapter titled Mentalese, he explains why the notion that people ‘think in’ a certain language is not just wrong, but also absurd. The idea itself is common enough that most people implicitly accept it to be true. For example, Pinker notes George Orwell’s idea of Newspeak, a language developed by a totalitarian state that has no words for freedom, or equality and so forth… Orwell says that ‘in so far as thought is determined by words, the people who knew no language other than Newspeak would have no idea of political freedom’.
Pinker then points out that if thoughts were determined by words – any words, to say nothing of words of a particular language – one wouldn’t be able to teach a child a language to begin with, or say something when one meant something else, or coin new words, and so on. The right way to look at thought and language is that we think in an abstract mental language (mentalese), which, it turns out, is universal in human beings; a caucasian’s mentalese is the same as that of a Chinese which is same as that of an African. The conversion from mentalese to an actual language takes some learning, and it is here that deaf people have a problem.
Learning a language, at least insofar as internalizing it goes, becomes very steeply harder with age. It has been noted, for example, that people who are congenitally deaf have a hard time expressing themselves, if their deafness wasn’t discovered early enough, or if they weren’t taught sign language early enough. It may seem that this might make one think that the deaf think ‘in sign language’, but this isn’t true. Congenitally deaf people are just as intelligent as normal people in non-verbal modes of intelligence. (They have an obvious handicap, if they haven’t been taught sign language, when it comes to verbal intelligence tests).
In short, then, deaf people think in the same language that non-deaf people think in – mentalese. They just have no outlet which is as convenient as non-deaf people (and I should know, mind… I can’t mime a galloping horse, much less memorise an abstract movement for one!).
