Beyond the argument from design

Willem H. Zuidema, T. O’Donnell, A. Cangelosi, Andrew D. M. Smith, Kenny Smith

Evolang

Abstract

Many studies of the evolutionary origins of human language capabilities rely on what is sometimes called the “ Argument from Design “. Such studies attempt to establish that a given feature of that capacity is (i) too complex to have arisen by chance, and (ii) appears to be specifically designed for processing natural languages. It is argued that the theory of natural selection is the only scientific theory that can explain the appearance of complex, adaptive design, and, hence, that the conclusion that the feature evolved as an adaptation for language is unavoidable. We will not, at this point, address the many disagreements about the linguistic data used in such studies, or questions about whether or not given processing abilities are specific for language, or about whether or not objective measures for complexity exist. Rather, we analyze the validity of reasoning with the argument from design when studying culturally transmitted systems such as natural language or music. We show that in these systems such reasoning is unsound, because there exists an alternative scientific explanation for the appearance of design that can be termed “ cultural evolution “. As a simple example, consider the evidence reviewed in Pinker and Jackendoff (2005) showing that other primates, including chimpanzees, have difficulties distinguishing human phonemes and/or make phoneme boundaries differently from humans. Pinker & Jackendoff conclude that human speech perception is special, and must therefore, they imply, be adapted for language in the biological sense. However, it is easy to show – as we do in figure 1 using a variant of the model from Zuidema and Westermann (2003) – that if a language is transmitted and negotiated culturally, and allowed to change based on success and failure in recognition, any arbitrary features of the perceptual system will be reflected in the configuration of