Order, disorder, evolution
The force of evidence from modern language
Theodosius Dobzhansky (1937), Paul Nurse (2020), and many others, propose that evolution is crucial to any understanding of how biology works. Noam Chomsky (2022) proposes that this includes language.
By the proposal here, in this evolution there must have been at least eight steps, the last being the least thoroughly fixated and the most vulnerable to mishap.
This proposal at least reduces any need for postulating specific malformations. Following many others in the same tradition, Lawrence Shriberg et al (2005) call for particular ‘phenotypes’ of disorder. An evolutionary model reverses this, simplifying the theory of disorder. as required in science generally, by an idea generally known as ‘Occam’s razor’ (William of Ockham lived in the 14th century).
The learner’s task
In learning to talk there is a lot to learn.
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.
Taken together, speech and language constitute the most complex system known to science. And yet they are effortlessly acquired by the overwhelming majority of children with no necessary help in about ten years. This would be quite unachievable unless speech and language were built as structures. Syllables are built from consonants and vowels. Consonants and vowels are built from what are now known as ‘features’. Syllables combine with each other to form structures known as ‘feet’. Feet and parts of feet combine to form words, words combine to form phrases, and phrases combine to form sentences, in all cases according to the features they contain. The features are thus the minimal defining property of the system as a whole.
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.
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.