The special phonological talents of humans, reviewed in the previous chapter, demand an explanation. This chapter articulates two rival accounts for these facts. One view asserts that humans are biologically equipped with a specialized system for phonological patterning, the phonological grammar. The productivity of phonological patterns, their spontaneous emergence and universality all spring from two broad properties of the system: its algebraic computational machinery, and the presence of substantive universal constraints on the structure of potential phonological patterns. On an alternative explanation, the phonological talents of humans result from systems that are not specialized for phonological patterning. The following discussion outlines these two competing hypotheses as the basis for their evaluation, in subsequent chapters.

The phonological grammar is a core algebraic system

Humans are equipped with remarkable phonological talents. We instinctively recognize phonological patterns in the structure of our language, we spontaneously generate phonological systems anew, and the patterns we produce have some recurrent and potentially unique design properties.

Preface

This book concerns a linguistic human compulsion – our tendency to assemble words that comprise internal patterns. All natural languages manifest such patterns – no known human tongue uses only single atomic sounds as words (e.g., “a o u” for ‘I love you’). Rather, words are intricately woven from smaller meaningless elements that form systematic patterns – we contrast god with dog and blog with globe. We begin spinning these webs in the womb, and we do so prodigiously, not only for familiar words but also for ones that we have never heard before. Our instinct to form those meaningless patterns is so robust that children have been shown to generate them spontaneously, even if they have witnessed no such patterns in their own linguistic community. In fact, people impose these patterns not only on their natural linguistic communication but also on their invented cultural technologies – reading and writing. This book seeks to unveil the basis of this human compulsion.

The human capacity to weave linguistic messages from patterns of meaningless elements (typically, speech sound) is phonology. Phonology has been the subject of much previous research, mostly in linguistics and psychology. For the most part, however, these efforts have proceeded in parallel lines across different disciplines, and as a result our understanding of the phonological mind remains fragmentary. Linguists (specifically, those in the field of formal phonology) have mostly concerned themselves with the structure of the phonological grammar, but the cognitive mechanisms underlying phonological patterns are rarely considered. Psychologists, for their part, have assumed without question that phonological patterns can be adequately handled by rather simple, non-specialized computational systems, but these investigations remain largely divorced from the progress made in formal phonological theory in recent decades. This book seeks to bridge the interdisciplinary divide and reconsider phonology in a new light.

In previous chapters, we have considered the possibility that the human mind possesses a system specialized for phonological patterning. How special is this capacity? Is it unique to humans, or shared with other animals? To address this question, we examine three defining features of human phonological systems: (a) their reliance on algebraic computational machinery, (b) their assembly by the conjunction of learning and universal, substantive constraints, and (c) their tendency to optimize analog phonetic pressures using algebraic means. We next proceed to investigate whether those three capacities are available to nonhuman animals. Anticipating the conclusions, neither algebraic machinery nor the capacity to shape communication patterns by both learning and innate knowledge are uniquely human, as each of these separate capacities is widely attested in the animal kingdom. But surprisingly, few species combine them in their natural communication systems, and no comparable case is attested in nonhuman primates. Precisely because these two ingredients (algebraic machinery and substantive constraints) are widely available to nonhumans, their unusual conjunction in human phonology is likely due to some modification to the human genome and brain that regulates the spontaneous, systematic capacity of humans to engage in phonological patterning.

The human phonological instinct from a comparative perspective

The discussion in this book has so far concerned itself with the specialization of the phonological mind – whether humans possess a specialized mechanism, equipped with innate universal constraints that specifically target the structure of phonological patterns. The question of specialization is important because it touches on the age-old debate concerning the origins of human knowledge – whether our knowledge and beliefs are induced from experience, or shaped a priori by our biology. The results presented so far open up the possibility that the phonological mind might indeed be specialized in this manner. We have seen that disparate phonological systems manifest a uniform design that distinguishes them from nonlinguistic patterns, speakers of different languages exhibit knowledge of these principles even when they are unattested in their language, and there is some evidence that this design is present already in early development. All these results suggest that the phonological mind might be a specialized system of core knowledge. But once the possibility of specialization arises, a new question immediately comes to mind: Is this design special? Is the makeup of the phonological mind similar to other systems of animal communication, or is human phonology unique in some way?