How will a child learn to express themselves in the absence of verbal communication?

Question

I'm curious to understand - if you don't teach a child how to speak then will the child develop a new language to express itself?

When a newborn is brought into the family everyone wants to look at it, talk to it, play with it, etc. The child learns by constantly observing, processing and reacting, and children have a very adaptable mind. Unlike adults they pick up things faster because their minds aren't subject to inertia.

So if you play with a child, smile, laugh and take care of it well, but never talk to it then how will it learn to express itself? I know that talking to a child is very important - mothers talk to their children to make them feel safe, and sing lullabies to make them fall asleep. Nevertheless, assuming that everything else remains the same what will the child learn in the absence of verbal communication?

Answer 1

No, a child will not teach themselves to develop a new "language" to express themselves, at least not by any generally accepted definition of the term "language".

Language is a complex tool used by multiple people or a community. A single child who is never exposed to verbal language does not make up their own... what would be the point if no one understood them?

A complete lack of exposure to verbal communication is a form of abuse, plain and simple. Numerous examples have been seen of what this does to so-called "feral children", and extreme difficulty in picking up verbal languages after these children are rescued from their neglected/abusive living conditions is pretty common.

It is widely believed that the ability to easily pick up verbal language is tied directly to a specific window of age. This critical period hypothesis states:

The critical period hypothesis states that the first few years of life is the crucial time in which an individual can acquire a first language if presented with adequate stimuli. If language input doesn't occur until after this time, the individual will never achieve a full command of language—especially grammatical systems.

So no, the child won't teach themselves language, and in fact the chances are excellent that they would never be able to fully develop the language skills most people are capable of.

Answer 2

This is the "forbidden experiment"-- linguist wish they new more about this because it has implications for other questions. But doing this to children is barbaric child abuse. So we wait for natural experiments to arise. The best documented ones are the ones Beofett covered, so I won't repeat that part.

The cases of feral children and children locked up and kept from human interaction have the problem that the children are treated horribly and not socialized. So what destroyed their ability to speak? The lack of linguistic input or the fact that they were in situation with no social interaction of any sort?

Well, this experiment is actually on going at the moment every time the parents of deaf children decide not to teach their children sign language. There was one case where parents of a deaf child decided not to sign with their child assuming the kid would pick up English from lip reading-- the child otherwise had loving parents, a comfortable home, toys, etc, just no signing and he couldn't hear anything. And lip reading English is a superpower that doesn't really exist-- so he didn't spontaneously learn lipreading. The kid instead spontaneously created his own signing system that he used with himself. This has happened several times, enough that a researcher was able to examine the various systems in the home sign systems that children created and found novel grammar-- indications that this was a language and not just a few isolated signs, gestures or other things that don't rise to the level of language.

When discussing home sign systems though, at the moment, the topic immediately changes to the incredibly low status of home sign in the US at the moment-- and for good reason, home sign is a shadow of the complexity of ASL and doesn't give you entry to the general Deaf community.

On the topic of the critical period-- it also affects 2nd language acquisition. If you learn a language too long after the critical period, you can't gain near-native fluency. For 2nd language learning, the ability to learn starts dramatically declining at around 11-14 and declines until about 20 where the difficulty of learning a 2nd language stays the same for the rest of the life.

Ref Talking Hands, Margalit Fox