Evolutionary Linguistics: A New Look at an Old Landscape

Abstract

This article explores the evolution of language, focusing on insights derived from observations and experiments in animals, guided by current theoretical problems that were inspired by the generative theory of grammar, and carried forward in substantial ways to the present by psycholinguists working on child language acquisition. We suggest that over the past few years, there has been a shift with respect to empirical studies of animals targeting questions of language evolution. In particular, rather than focus exclusively on the ways in which animals communicate, either naturally or by means of artificially acquired symbol systems, more recent work has focused on the underlying computational mechanisms subserving the language faculty and the ability of nonhuman animals to acquire these in some form. This shift in emphasis has brought biologists studying animals in closer contact with linguists studying the formal aspects of language, and has opened the door to a new line of empirical inquiry that we label evolingo. Here we review some of the exciting new findings in the evolingo area, focusing in particular on aspects of semantics and syntax. With respect to semantics, we suggest that some of the apparently distinctive and uniquely linguistic conceptual distinctions may have their origins in nonlinguistic conceptual representations; as one example, we present data on nonhuman primates and their capacity to represent a singular–plural distinction in the absence of language. With respect to syntax, we focus on both statistical and rule-based problems, especially the most recent attempts to explore different layers within the Chomsky hierarchy; here, we discuss work on tamarins and starlings, highlighting differences in the patterns of results as well as differences in methodology that speak to potential issues of learnability. We conclude by highlighting some of the exciting questions that lie ahead, as well as some of the methodological challenges that face both comparative and developmental studies of language evolution.

Notes

¹The evidence for structurally dependent compositionality in language is captured well by the example of subsective adjectives like big and tall (see (Barner & Snedeker, 2007; Kamp & Partee, 1995; Partee, 1995) for experimental evidence of compositional knowledge in young children). When subsective adjectives like big (A) combine with nouns like fish (B) to form a noun phrase like big fish (A + B), actual big fish are identified according to the typical sizes of fish (Bierwisch, 1989; Cresswell, 1976; Kennedy, 1999; Klein, 1991). Fish that are bigger than average, or bigger than most other fish, are categorized as big fish. The range of sizes specified by big thus depends on the noun that it combines with and the set of things in the world this noun is used to pick out (contrast big mouse vs. big elephant). For this reason, inferences of the following kind are not valid (Partee, 1995):

1. Goldie is a big fish.

   Goldie is a pet.

   Therefore Goldie is a big pet.

As recently shown by Barner and Snedeker (2007), even 4-year-old children are able to use this type of compositional knowledge to apply adjectives like tall to novel sets of objects, and to shift what counts as tall depending on the typical sizes of kind members.

²Actually, this condition was Experiment 3 of the Marcus, Vijayan, Rao, and Vishton (1999) study. However, this experiment captures the essentials of the study most cleanly and was the one used to test tamarin monkeys, so we focus on it here.