Normalities, abnormalities, and the limits of statistics

Serious abnormalities are mostly rather obvious. At a given point on a scale they count as impairments. But what defines the point? And what defines the scale?

My clinical focus is on disorders of speech and language and the various interactions between what are known as ‘syntax‘ – how words fit together – ‘morphology‘ or how words are built – and ‘phonology‘ – or how the sounds in words are built. These things may be hard or impossible to represent as points on scales or percentages. The number of words or the ‘lexicon‘ can in principle be counted, but that is only in principle, The number relates only to the words that are said, not the number of words that are understood. These often comprise the main issues which get noticed in children and young people’s speech.

Unusual or abnormal development is not, in itself, a disorder, The diagnostic question relates only to the degree of abnormality and how much it matters yo the child in any given case. But there are issue which do not resolve spontaneously, which the individual may be left with for life. Such issues can be revealed by extreme degrees of abnormality. To this degree, abnormality can be diagnostic.

On the development of speech, there are a number of fundamentals. One of these concerns the development of syllables as parts of words. English happens to have a relatively rich inventory of both vowels and consonants and an unsually complex foot structure. And English is very permissive about how sounds combine in the syllable – what is known as the ‘phonotactics‘. Children tend to have many more difficulties with the consonants than with the vowels. But some children have great difficulties with both or even more difficulties with vowels than with consonants. Or they don’t recognise the syllable as a category, treating any consonant before the vowel, what is known as the ‘onset’, as just an extension of the vowel.

The sounds of most words in English are not deeply influenced by the sounds around them. In many languages these effects of words on the sounding of adjacent words is much more extensive than it is in English, But children are not given any guidance or privileged information on this. Nor could they be. Where English stands in the learnability space is not a matter for discourse with children. But in children’s speech there are interactions between words and between the parts of words inside the words which are most definitely not part of English. And some of these interactions are like points on a pathway. So there is a natural pathway from little, often hard to say even at four, to monopoly, often hard to say at seven or eight or even in adulthood. The T in little and the P in monopoly both get pronounced with more contrast between them and two other sounds – as LIKU and MONOKOLI. This is known linguistically as ‘disharmony’ or ‘dissimilation’. By nine most children can say most words, even the more difficult ones like monopoly. But those who can’t sometimes need help.