A friend of mine is a speech therapist and whilst out for dinner the other evening we chatted about when a child's speech may give cause for concern.
Montessori wrote about the sensitive periods of which there are five main ones:
A sensitive period for movement
A sensitive period for small objects
A sensitive period for language
A sensitive period for social aspects
A sensitive period for refinement of the senses
They are all linked to what she called 'The Human Tendencies'. These tendencies are innate and drive us to behave in a particular way. The tendencies are linked to survival and therefore include things like order, movement, exactitude, precision, communication, exploration, socialisation and repetition.
For example: The need for survival means that there is a drive to find food, for this there needs to be exploration. With exploration comes the need to repeat and be precise. Making tools to hunt needs precision and exactitude and then sharing what you have learned with others requires communication. The need to reproduce means man needs to socialise and communicate...as you can see, these inner behaviours are all part of our make up.
Of course, I am not insinuating that we're still on the hunt for woolly mammoths with spears, but our inner drive has not changed.
This therefore means that the sensitive periods that Montessori talks about are naturally occurring, innate and every child will go through them as and when they are ready to do so.
If we have faith in the child that they will require the need to be social as this is an innate desire of man, this will allow us to have faith that a child will pass through the sensitive period for language because they will need language to enable communication, to enable socialisation.
Of course, it is possible for children to pass through these sensitive periods void of stimulus, this will not enable them to repeat or refine their skills. If they are not talked to, then their is less chance that they will be confident and fluent talkers. Looking at other people who wrote about Language development one will soon discover that language development comes from a range of stimuli. Chomsky would say that all children are born with what he called a Language Acquisition Device; in other words, regardless of anything, a child has an innate ability to develop language. However, Bruner and Piaget argued that children needed stimulus and that had to come from the adults around them. I think over the years this has become undisputed. We have seen horrific things on the television in the past about Romanian orphans who have just been left in cots for hours on end without stimulus. The results to my uneducated eye, are conclusively detrimental. Behaviour is irrational and disturbed and language almost non existent, at least in so far as the use of clear words.
So, providing stimulus, talking to the child, giving them the opportunity to listen to stories or rhymes, sing songs or play games that involve language will enable the child to move through the sensitive period for language normally and, just as all children don't walk at the same age because they don't all go through the sensitive period for movement simultaneously, they won't all talk at the same age. Stimulate and trust your child and they will likely develop language when they are ready, however, if you are at all worried, chat with your child's nursery teacher or with your health visitor.