Is the communication development of Multiple Birth Children different from single born children?
Is the speech and language development of twins & higher multiple birth children different to single born children?
By Dr Sandra McMahon B.App.Sc.(Sp. Path.), PhD., MSPA
Obviously MBC as with all children, show a continuum from severe communication difficulties right through to accelerated speech and language. However, most research indicates that MBC are at risk of delays in comparison with singletons. The interesting point is that many of these early delays are transitory delays predominantly occurring during preschool years. However, it has also been shown that while delays compared to singletons may decrease with age, difficulties in reading, spelling and numeracy may result from these delays during the early years.
To communicate we use a number of different communication skills (eg. grammar, vocabulary, clarity of speech.) MBC do not generally show overall delays in all areas of communication; but, my research involving 40 MB sets indicated that a mild impairment in at least one communication skill occurred in all but 10 per cent (i.e. 4) of the children. This information relates to twins and higher multiple birth children. Additional information in regard to higher multiple birth sets will be discussed in Article 4.
I will just briefly run through each communication skill to indicate the most frequent problems observed with MBC.
Research suggests that the syntax or grammar of MBC tends to be delayed compared to most singletons. However many MBC, while slower in development, are not necessarily impaired i.e. they tend to be right at the lower end of the normal range for things like the length and complexity of their sentences. This suggests that MBC may be at risk in terms of grammatical development and could be less developed than many of the other children of similar ages during the preschool years. Many of the sets did not use “full sentences” leaving out key parts that can make it difficult to understand what they are trying to talk about. Eg. They may not indicate “who” is doing something such as saying “…driving car” rather than “Daddy is driving the car”. Leaving out the “little words” such as “has” and “had” can change the meaning of a sentence and create frustration on everyone’s part! eg “Jesse car keys” could mean “Jesse has the car keys” or “Jesse had the car keys!”.
Past literature indicates that MBC’s vocabulary (i.e., number of different words that they say) does tend to be delayed compared to singletons. They tend to use a smaller variety of words on a day to day basis even if they can say more words; although their total vocabulary is also more likely to be reduced compared to similar age single born children. An interesting point is that my research showed that, with an adult encouraging conversation, the MBC’s vocabulary was not any different from that of the singletons. This perhaps suggests that their vocabulary levels are better than they present when playing with siblings or other children. Also they me be getting less “practice” at using their words which can have longer term implications. Therefore if they were prompted to use different words they were able to remember them and use them in their conversation. This points out the importance of parent interactions for communication development. Supporting vocabulary is very important as it has been strongly linked with later IQ levels and early school success.
Research has indicated that MBC have a higher incidence of speech problems than singletons. However, there are a number of factors to be considered when looking at why a child’s speech is difficult to understand.
Firstly is the child able to physically make the speech sounds? MBC do not show problems in saying their sounds. Where they have more difficulty than singleton children is with the development of phonological process (i.e., learning the rules of how to put sounds together to form words). Some of these processes are part of the normal development of speech for all children. For example many two year-olds will say ‘tat’ for ‘cat’ as they are still using the immature rule (phonological process). In this example they are using an immature rule called “fronting” – this means sounds said using the back of the tongue (k, g) are said with the front of the tongue so they sound like /t/ and /d/. This immature rule is usually gone by about 3 and half years of age. If a child is still using this immature rule after this age it would be considered a delay in speech development. In my research 76 per cent of the MBC displayed varying degrees of delayed phonological/ speech development. This is a much higher percentage than is expected in the single born children.
Some children use unusual phonological processes or atypical rules that most other children never use and we refer to their speech as disordered. As we don’t hear these unusual processes very often it makes it really hard to guess what these children are saying. E.g., they may distort their vowel sounds. For example the word ‘dog‘ may be said as ‘dug‘; or change all first sounds to ‘sw’ so ‘shirt’ – ‘swirt’ and ‘frog’ -‘swog’. In the five year old singleton population the prevalence of unusual phonological processes is about three per cent. However in my study 72 per cent of 2 to 4 year old MBC used unusual processes.
Hence MBC tend to be at risk of speech clarity problems i.e., the speech of MBC may be difficult to understand, displaying delayed and/or disordered speech.
Social Use of Speech:
Again significant differences between MBC and singletons have been shown in regard to how the MBC use their language. As MBC are frequently playing with each other, they tend to be better at some social uses of languages such as turn taking, however difficulties also arise. They have been shown to initiate verbal interactions less as individuals, and use fewer questions and statements. We will discuss why this may be in later articles but one suggestion is that as their multiple birth siblings may be initiating interactions with others they do not have to do it as individuals – at least not as often as a singleton child might have to.
So in summary to the question ‘Are MBC different from singletons in their communication development?’ – Often Yes. While some MBC will show early speech and language development, many may be at risk of delays in development in at least one communication skill. Spoken sentence development and poor speech clarity are the two most common difficulties and therefore require the most modelling and monitoring. As we know MBC are at risk of early communication development, it is important for parents to focus and build their skills in encouraging early communication skills from birth – remember Babies Talk TOO – and encouraging imitation skills can begin as early as 4 months of age. Further ways parents can put MBC’s communication on the right track from the start will be discussed in Article 6. All the suggestions you read for “late talkers” will also assist.
So we know MBC might be showing some different developmental milestones to single born children BUT do children within MB sets sound the same and function at the same level? – Do they have their own language? This is addressed in Article 2.
Dr Sandra McMahon, www. speechnet.com.au (07) 33499234
Speech Pathologist, PhD, MSPA
This is a series of articles providing some information about the communication development of multiple birth children (MBC) (twins, triplets, quadruplets and quintuplets!). The information is drawn from current research as well as research that I conducted as part of my PHD research at the University of Queensland. This research was investigating communication development and later literacy skills in multiple birth children. This series will discuss the following common questions asked about MBC:
Article 1: Is the communication development of MBC different from single born children (or singletons)?
Article 2: Do children within MB sets sound the same and function at the same level? – Do they have their own language?
Article 3: Is the communication development of Higher Multiple Birth Children (triplets, quintuplets, quadruplets) different from twins???
Article 4: Why should the communication development of MBC be any different from any other children?
Article 5: How can we help their communication development?
Director SpeechNet Speech Pathology.
The following provides a list of key publications by Dr McMahon:
Refereed Publications (note: McEvoy is nee McMahon)
IS THERE A TWIN LANGUAGE?
By Dr Sandra McMahon, B. App. Sc. (Speech Pathology), PhD, MSPA, Director SpeechNet Speech Pathology Qld
This is the second in a series of articles on MBC.
Past research as well as research conducted by Dr Sandra McMahon at the University of Queensland suggests that multiple birth children have unique requirements in order to assist them to develop to their optimum communication development.
This series of articles aim to briefly address some of the more common questions asked about MBC. These include:
Past researchers originally linked the genetic base of the MBC to how similar the children would be. As you are probably aware twins can be identical, where one egg splits into two so that the children have the same genetic make-up; or two or more eggs can be released so that fraternal children with different genetic make-up occurs. Researchers hence predicted that if communication skills are genetically based, children with the most similar make-up (i.e. identical twins) should be ‘most’ similar in their communication development. Unfortunately no conclusive answers as to whether identical twins were more similar ·than fraternal twins has been found in the research over the years. Opinions differed depending on what communication skill they observed and what methodology they used.
Some researchers did claim however that MBC used a unique language that only the MBC in the set could understand – i.e., it was thought that MBC had their ‘own language’. The figure of 40% of MBC having their own language is often bandied around in the literature. However, any descriptions or evidence of these ‘unique’ languages are very poor and many other researchers report that such unique languages really do not exist.
My research aimed to look at the similarities and differences between siblings within multiple birth sets and to investigate the legitimacy of the claims of them having their own languages.
19 sets of MBC were looked at in this particular study. There was no statistical difference between siblings in a set for any of the communication skills such as grammar, vocabulary and use of language i.e., they were basically at the same developmental levels. However for grammar frequently one child in the set was very slightly more advanced (their sentences were more mature).
The speech of the siblings within multiple sets was very similar. If one child had speech problems such as a phonological delay (i.e., slow at learning the rules of putting sounds together to form words) so did the other child in the set for all but two sets of the 19 sets. While multiple birth siblings had similar speech errors, their speech was not identical as perhaps would be the case if they were using their own language. Why was the speech not identical?
It was found that MBC use a higher percentage of unusual processes than singletons. As unusual processes (such as changing the vowel sounds in words, starting all words with the /d/ sound) are not heard frequently in most developing children, they make speech more difficult to be underst00d by adults. This could be misinterpreted that the children are inventing words rather than acknowledging that it may in fact be a speech disorder where they are using the incorrect speech rules.
If MBC had their own language you would expect them to understand each other’s context free speech at least as equally as well as they understand adult speech. But this was not the case in the research conducted by Dr McMahon.
So in summary, Yes the speech of children within a multiple birth set are very similar although one child may be very slightly better with grammar, intelligibility of speech and how they use their language. There is no “real” evidence that MBC have their own language although it is easy to see why this belief has developed. Their development is similar, they often share some unusual phonological processes and hence may say some words in the same ‘funny’ way and they do seem to understand each other better than other children they are playing with.
Perhaps rather than “twin language” their speech is characterised by speech difficulties. In view of the high percentage of speech errors observed in twins and triplets if they seem to have unclear speech, investigation and support may be warranted. This leads to the questions as to whether the multiple birth children should be separated so that their speech problems are not reinforced by each other. The pros and cons of this is discussed in Article 3.
Dr Sandra McMahon, www.speechnet.com.au Ph: 07 3349 9234
Director, SpeechNet Speech Pathology.
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The literature clearly indicates
Please find attached information that will help inform you about your child’s speech development and information if you are asking “Should I get my child assessed?”