One of the two most complex systems known to science

The other being matter and the universe

Despite the complexity, speech and language are effortlessly acquired by the overwhelming majority of children wityhout any external intervention in the form of overt teaching in about ten years. There seems to be a highly evolved faculty which allows humans to reliably navigate the pathway here. The child constructs an intricate grammar from random experiences.  By the biolinguistic assumptions here, this has to be specified as part of the human genome. Any capacity specified by the genome can be misspecified to any degree.

This pathway would not be navigable unless speech and language were built as structures, with syllables built from different sorts of speech sound or ‘phoneme’, both consonants and vowels built from what are now  known as ‘features’, syllables combining with each other to form structures known as ‘feet’, feet and parts of feet combining to form words, words combining to form phrases, and phrases combining to form sentences.

By a point originally due to William Holder (arguably the first speech and language therapist) in 1669, the features are thus a minimal defining property, not phonemes, as sometimes suggested.

All languages define their grammar on phrases, rather than words. So in English we say “the rightful head of the commonwealth’s responsibilities” with the ‘S at the end of the phrase the rightful head of the commonwealth rather than after the word head.

By these aspects of the framework here (widely, though not universally agreed), the contrasts are universal, between vowels and consonants, between pronounced and unpronounced structure, between content and non-content words and elements like yes and no which are neither one nor the other, but vestiges of a system, by the proposal here, predating grammar. But the way these things are organised varies from language to language, and thus have to be learnt  along with the words. And children can have problems with any one or more of them.

For children

At first the complexity may be quite daunting for the child. But gradually over the first ten or so years of life, the child learns to talk, and if he or she goes to school, learns to read and write. At least most children do. But some have difficulties of one sort or another. These are what I refer to here as issues of ‘learnability‘. The process continues until the child reaches puberty. And then it gradually stops. Remarkably, in a way quite unlike other areas of human skill, in art, music, sport, learnability with respect to speech and language is finite. So we can speak of a speech defect or a foreign accent. If learnability was not finite, these terms would be meaningless.

There is a crucial distinction here between delay and disorder. In principle there is natural pathway of acquisition. First children can say one word, then two. Children’s first syllables are mostly built from single vowels or consonants. Then they start to string the consonants together at the beginnings and ends of words in words like black, blue and vest, and to assemble syllables into more complex structures, as in names like Damian and Deborah, and words like yellow and soldier. Obviously, this pathway is not a simple thing. Just as children start to walk at different ages, so it is with talking. So one five year old may be saying soldier in the adult way (and this is the only word in English with this sequence of sounds in the middle), and another may be saying it as SHOULDER, with part of the sound structure hopping left into the first sound. This may be still happening at seven or eight. If there are a lot of seemingly simple words similarly mispronounced at seven or eight,  the development of the pronunciation patterns would seem to be at least delayed. The child is navigating at least this part of the pathway later than most others.

There are various factors which can obstruct the natural tempo here. Some children have little or no opportunity to discuss with an adult whatever happens to interest them. Or they may never see a children’s book. But there is also the sense of  family security. In the limit, it may be dangerous to go outside the front door. A four year old in this kind of situation once said to me sadly, but accurately: “We all be in a jail”. Such insecurity can massivlely delay speech and language.

This contrasts with disorder. If a five year old is saying soldier as HOHWOOV, his or her speech may be almost or completely incomprehensible. Such speech is clearly disordered. The development is not following the normal pathway. Such a child needs professional help.

If the development is just delayed, as the delay increases, so does the case for intervention. Only one word at two is just late. Only one word at three is significantly abnormal.

But the distinction between delay and disorder is fuzzy. As the degree of either increases, so does the possibility that the issue will not resolve spontaneously. Some individuals go through life with speech and language issues. If the issues are severe, they are mostly made aware of this, by failing exams, by not getting jobs, or just by self-awareness. For the speech and language clinician, the goal is to try and prevent any such outcome.

Developmentally

the child has to work out that there is a difference between a word, with a rhythmic series of feet, and syllables within the feet, and the domain over which stress is computed, consisting of a vowel, and one or two syllables to the right. Crucially the consonant or consonants before the stress domain have nothing to do with the stress. And there may be a whole syllable before this which is not counted either. The complexity here is easily missed. Hence banana as NAHNA or BAHNA, and later on monopoly as OPOLI or NOPOLI.

But signficantly the opposite seems to be unattested. Children learning English seem to have little difficulty learning the right-to-left the direction of what is known as the ‘scansion’. We do not hear children saying banana as BANAH, 0r monopoly as MONOPOL – leaving out the final syllable or final vowel. There may be a child doing this, but I have yet to come across or hear of one. In modern Scottish Gaelic and many other languages, stress is computed from left to right. The direction of the scansion is something which has to be learnt – within the learnability space.

Expressive and receptive language

By a distinction largely dictated by psychologists (rather than linguists), many tests of language development distinguish between ‘expressive’ or ‘productive’ language’ and ‘receptive language’ or ‘comprehension’, using different criteria according to what is being tested. Small children can often identify exotic animals from their pictures long before they start using the names, and respond appropriately to instructions before they give equivalent instructions themselves. Where there seems to be a developmental issue, the difference can seem even more stark between comprehension and expressive language. So there is a notion of Specific Expressive Language Delay or Disorder or SELD. This is sometimes used as a diagnostic category, often based on a difference between children’s scores on tests of their comprehension and their expressive language. But this is not sufficient to force the conclusion that expressive and receptive language represent separate areas of cognition. Part of the problem here is that it is difficult to test these things symmetrically. For instance, many of the most naturally plausible ways of testing comprehension are with respect to answers to questions beginning with who, what, where, when, why and how, or requiring Yes or No as an answer. But it is difficult to devise test protocols which require children to ask corresponding sorts of questions in similarly natural and plausible ways. So tests of comprehension and expressive language may be testing different things. And the differences on the scores may be an artifact of the differences between the protocols. A similar difference may underly the common observation about more normally developing children.

The apparent discontinuity with reception before expression in almost all areas of language in almost all children may be due to any number of intervening factors – including memory, familiarity, and the demands of the context. It is also possible, as the framework here would dictate, that there are just different degrees of competence, yielding different results according to how these are tested.

In other words, tbere may be no such thing as an ‘expressive language disorder’ as a well-defined defect.

It might seem possible in principle to devise a fully symmetrical test of expressive and receptive language. But in the absence of such a thing, the difference here may be artifactual. Tests of ‘expressive’ and ‘receptive’ language may may be just tapping different capacities.

Novelty

The novelty of the framework here, largely thanks to the work of Noam  Chomsky, is  in the reasoning which gives a critical role to the contrast between what is generated and what is not generated, each as important as the other, in a way parallel to the contrast between zero and one in mathematics.

Leaving things unsaid

For example, all languages allow elements to go unpronounced, first evidenced by first language learners of English in the first one-word answers to questions with who, what, or where, as by “Pocket” as an answer to the question “Where’s your pencil?” These unpronounced elements are critical for the way these sentences are understood.

Humans have thus evolved a mental structure which makes it possible for learners, even small learners, to ‘understand’ elements which are not where they are pronounced.

By the proposal of Shigeru Miyagawa (2010), aspects of both of these seemingly universal phenomena are at the dictates of discourse, and thus such that they could have evolved to be the way they are. That does not alter the fact that there is a significant learnability issue here. If one term in a genomic Universal Grammar is disrupted there may be wide-ranging negative consequences for language development.

Not behaviour

Although practise and familiarity are obviously relevant, by the framework here, speech and language are plainly not behaviour in the ordinary sense of this word.