Are multiples more likely to be delayed and why?
In the preschool years all children develop language skills. Over the last 70 years many studies have indicated this is the area where twins and higher multiples are most likely to be different from single-born children. Thus language is the main focus of this section. Delays in language have complex and wide-ranging implications for children's development. Multiples may be behind singletons in their articulation and in their ability to express themselves. Their sentences may be shorter and baby talk may persist longer. They are usually much less delayed in their receptive skills. That is in their knowledge of vocabulary and their ability to comprehend what is said to them. Therefore if multiples have very poor speech, don't dismiss this potential problem because their vocabulary is good and they understand what you are saying.
We emphasise that problems in speech and language do not necessarily imply any intellectual delay in twins. In areas of ability that do not depend upon language, multiples and single-born children do equally as well. Thus there may be difficulties in school achievement and a slightly greater chance of Reading Disability.
However consider just how many abilities do relate to language in twins. Words are symbols for objects and multiples may be delayed in other areas involving symbols. By two years children should be starting symbolic play where for example a cardboard box may symbolise a house or a car. The delays of multiples can extend to how their play develops and sometimes this is complicated by delays in fine-motor co-ordination. Preschool teachers report multiples may be delayed also in social maturity both in their behaviour towards the teacher and towards the other children.
This pattern of delays in language, in play, in social maturity and in fine-motor skills is much more consistent in twins than in singleborns. Unlike twins, single-borns may have a delay in one of these areas but not the others. This difference needs to be borne in mind when planning intervention. For example, one of our studies in Australia considered whether twins would benefit from being with other children in a playgroup for three year olds. The twins who benefited from this were those already fairly advanced in their language. Because of their delays in other areas as well as language, the less mature twins remained isolated from the other children.
How does the social situation of twins affect their language?
The conventional explanation of delays in twins focuses on their unique social situation. However recent studies have shown that some of the birth complications so common in multiples may best indicate which twins will have these language problems. One particular problem is Intrauterine Growth Retardation ("Small for gestational age" where multiples may not be very premature but have ceased to grow so well in the last few weeks before birth). It may be useful for the preschool teacher to know about this, especially if the multiples are still being seen regularly by a hospital or paediatrician as often happens if they were premature.
(i) It is still worth considering in detail the ways in which the social circumstances of preschool multiples are different. There are three main ways in which acquiring language is different for twins and higher multiples:
(ii) Parents are busier with two or more children the same age to care for and have less time to help them develop language skills. This means they may answer the children's questions more briefly, engage in less dialogue with just one child, brush over mispronunciations and generally have less time to be a good model for adult language. It does mean the children are better at understanding when something is said quickly!
(iii) The multiples are so familiar with each other's wants and body language that they may not need proper language to communicate. Sometimes they develop their own form of communication, the so-called "secret language" or cryptophasia which only they can understand. This idea of a unique language sounds very mysterious and romantic but is much less common in a fully developed form than the literature on twins would suggest. Any children who can come up with their own grammar and vocabulary must have very advanced language skills! More often it is not a secret language but a set of idiosyncratic manipulations of English, such as changing the first letter of every word to "b". The problem with such a form of communication is that it is fine at home where people are used to it, but is not adaptive in the wider world.
(iv) Multiples may compete with each other for adult attention. They often speak loudly and simply to get the attention of an adult and often interrupt each other's conversation. Again, the way they speak may be highly adaptive for this situation but not for life outside the home.
A classic neurological study is of the two year old twins who suddenly kept on falling down. What happened was that one worked out that if he fell down, he would get rapid attention and a cuddle. The other one identified this strategy and within two days they were falling like flies....So what does the parent do-and it did not need the neurologist?