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Biological Steps to Language‑Readiness
Pre‑Adaptations
In this section, I review some of the cognitive pre-adaptations which paved the way for the enormously impressive language capacity in humans. While these pre‑adaptations do not in themselves fully explain how the full, uniquely human ability finally emerged, they do give us a basis for beginning to understand what must have happened.
A pre‑adaptation is a change in a species which is not itself adaptive (i.e. is selectively neutral) but which paves the way for subsequent adaptive changes. For example, bipedalism set in train anatomical changes which culminated in the human vocal tract. Though speech is clearly adaptive, bipedalism is not itself an adaptation for speech; it is a pre‑adaptation. This example involves the hardware of language, the vocal tract.
Many changes in our specie’s software, our mental capacities, were necessary before we became language‑ready; these are cognitive pre‑adaptations for language. Preadaptations for language involved the following capacities or dispositions:
1. A pre‑phonetic capacity to perform speech sounds or manual gestures.
2. A pre‑syntactic capacity to organize longer sequences of sounds or gestures.
3. Pre‑semantic capacities:
a. to form basic concepts;
b. to construct more complex concepts (e.g. propositions);
c. to carry out mental calculations over complex concepts.
4. Pre‑pragmatic capacities:
a. to infer what mental calculations others can carry out;
b. to act cooperatively;
c. to attend to the same external situations as others;
d. to accept symbolic action as a surrogate for real action.
5. An elementary symbolic capacity to link sounds or gestures arbitrarily with basic concepts, such that perception of the action activates the concept, and attention to the concept may initiate the sound or gesture.
If some capacity is found in species distantly related to humans, this can indicate that it is an ancient, primitive capacity. Conversely, if only our nearest relatives, the apes, possess some capacity, we can conclude that it is a more recent evolutionary development. Twin recurring themes in the discussion of many of these abilities are learned, as opposed to innate, behaviour and voluntary control of behaviour.
Hurford Introduction
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