Unity and diversity in human language

Abstract

Human language is both highly diverse-different languages have different ways of achieving the same functional goals-and easily learnable. Any language allows its users to express virtually any thought they can conceptualize. These traits render human language unique in the biological world. Understanding the biological basis of language is thus both extremely challenging and fundamentally interesting. I review the literature on linguistic diversity and language universals, suggesting that an adequate notion of 'formal universals' provides a promising way to understand the facts of language acquisition, offering order in the face of the diversity of human languages. Formal universals are cross-linguistic generalizations, often of an abstract or implicational nature. They derive from cognitive capacities to perceive and process particular types of structures and biological constraints upon integration of the multiple systems involved in language. Such formal universals can be understood on the model of a general solution to a set of differential equations; each language is one particular solution. An explicit formal conception of human language that embraces both considerable diversity and underlying biological unity is possible, and fully compatible with modern evolutionary theory.

Statistical universals reveal the structures and functions of human music

“…Social context: Music tends to be performed predominantly in groups (17) and by males (18). The bias toward male performance is true of singing, but even more so of instrumental performance.…”

“…Classic typologies from anthropology and linguistics distinguish between absolute universals that occur without exception and statistical universals that occur with exceptions but significantly above chance (2,17,18). They also distinguish between universal features that concern the presence or absence of particular individual features and universal relationships that concern the conditional associations between multiple features (SI Discussion).…”

Empirical approaches to the study of language evolution

“…Because the term Blanguage evolution^can be interpreted either in terms of biological evolution of the language faculty or the cultural evolution of specific languages, Jim Hurford introduced the useful term Bglossogeny^to denote the latter specifically (Hurford, 1990). Although cultural and biological evolution are sometimes considered as mutually exclusive competing explanations (e.g., Christiansen & Chater, 2008), they are increasingly seen as complementary: glossogeny can explain much of the odd, language specific variability we see among different languages, and thus Btakes the pressure^off biological explanations from having to explain intricate details of language (Chomsky, 2010;Deacon, 1997;Fitch, 2008Fitch, , 2011d. The major review article in this issue by Simon Kirby gives an overview of the rapid advance of empirical and modeling approaches for understanding the nature and consequences of glossogeny (Kirby, 2017); Mark Pagel's article provides a further overview of how the study of glossogeny has progressed in the last decade (Pagel, 2016).…”

Evolutionary accounts of human behavioural diversity

“…More recently, some evolutionary psychologists have argued the evolved structure of the mind is likely to contain both domain-general and domain-specific mechanisms (e.g. [107,108]; see [109], for an example of a debate between domain-specific versus domaingeneral explanations of language learning). While we see no reason to expect context biases to always be domain general, the observation that they might sometimes be so characterized need not mean any fundamental incompatibility with evolutionary psychology.…”