Hurford's book, The Origins of Meaning, also addresses an interdisciplinary audience, extending to philosophers, psychologists, anthropologists, cognitive scientists and ethologists. The topic of language origins is an intellectual minefield, and those who tread on it need good balance — which Hurford has. Language, he neatly observes, allows humans to "go public with their thoughts".
A large part of the book reviews the experimental literature on the cognition of animals to model the protolinguistic substrates that probably characterized our earliest hominin ancestors.The late African grey parrot Alex, the famous vervet monkeys, and the chimpanzees Kanzi, Austin and Sherman are all here. So are a host of anonymous animals, such as bright piglets that back out of the 'wrong' arms of T-mazes, apparently to avoid giving incorrect responses. Do animals know what they know — that is, do they have self-awareness? Hurford shows that the seeds are there, and were probably present in our ancestors, providing fodder for natural selection.
Likewise, the capacity to realize something about objects (even that they are no longer present) is common to many animals and may have been a prerequisite for the emergence of the linguistic feature of 'displaced reference'. Hurford argues that the ability of many animals to infer animacy in objects (related to detecting biological motion) was necessary for our ancestors to evolve 'theory of mind'. Other comparative discussions include the evolution of episodic memory, which Hurford thinks emerged more recently than semantic memory, and the accurate perception of a number of objects without counting (usually around four), and the relationship of such abilities to the evolution of specific aspects of language.
Hurford locates an evolutionary starting point for language in early hominins in the simple two-way communications from which grammatical complexity and descriptive power eventually grew. He discusses physical and social environments of apes to locate possible precursors of group-wide reciprocal communications. He rejects male–female relationships and parent–offspring interactions because they are too asymmetrical, but views play behaviour among juveniles as more symmetrical and therefore a likely precursor. The literature on mother–infant interactions, however, indicates that these are not asymmetrical and may have been a focus of intense natural selection.
The discussions in The Origins of Meaning of ritualization, emulation, imitation, learning and 'machiavellian intelligence' are insightful. So is the review of communications that include gaze-following, attention-seeking behaviour, pointing, begging and alarm calls in non-human primates and/or young humans, and their possible implications for the evolution of referential language. After considering niche construction, kin and sexual selection, and reciprocal altruism, Hurford concludes that communicative cooperation and trust may have been the most crucial factors in the emergence of language.
There are some titillating nuggets in this book, such as a discussion of how the FOXP2 gene was mistakenly accepted as the 'magic bullet' responsible for language evolution. Even better is the extent to which academics from different countries use language competitively to show off — guess where Americans rank?
Has Hurford achieved his goal of describing the evolutionary foundations of language? Yes, elegantly and in accomplished detail that should be accessible to all those specialists the book targets. I look forward to finding out what he thinks happened next in the second volume.