Perspective ARTICLE

Front. Psychol., 08 June 2014 | doi: 10.3389/fpsyg.2014.00564

The integration hypothesis of human language evolution and the nature of contemporary languages

  • 1Department of Linguistics and Philosophy, Massachusetts Institute of Technology, Cambridge, MA, USA
  • 2Center for Research and Development of Higher Education, University of Tokyo, Tokyo, Japan
  • 3Department of Life Sciences, The University of Tokyo, Tokyo, Japan
  • 4Department of Electrical Engineering and Computer Science and Laboratory for Information and Decision Systems, Massachusetts Institute of Technology, Cambridge, MA, USA
  • 5Okanoya Emotional Information Project, Exploratory Research for Advanced Technology, Japan Science and Technology Agency, Tokyo, Japan

How human language arose is a mystery in the evolution of Homo sapiens. Miyagawa et al. (2013) put forward a proposal, which we will call the Integration Hypothesis of human language evolution, that holds that human language is composed of two components, E for expressive, and L for lexical. Each component has an antecedent in nature: E as found, for example, in birdsong, and L in, for example, the alarm calls of monkeys. E and L integrated uniquely in humans to give rise to language. A challenge to the Integration Hypothesis is that while these non-human systems are finite-state in nature, human language is known to require characterization by a non-finite state grammar. Our claim is that E and L, taken separately, are in fact finite-state; when a grammatical process crosses the boundary between E and L, it gives rise to the non-finite state character of human language. We provide empirical evidence for the Integration Hypothesis by showing that certain processes found in contemporary languages that have been characterized as non-finite state in nature can in fact be shown to be finite-state. We also speculate on how human language actually arose in evolution through the lens of the Integration Hypothesis.

Keywords: biolinguistics, language evolution, linguistics, birdsong, agreement, movement in language

Citation: Miyagawa S, Ojima S, Berwick RC and Okanoya K (2014) The integration hypothesis of human language evolution and the nature of contemporary languages. Front. Psychol. 5:564. doi: 10.3389/fpsyg.2014.00564

Received: 24 January 2014; Accepted: 21 May 2014;
Published online: 09 June 2014.

Edited by:

Andrea Moro, Institute for Advanced Study IUSS Pavia, Italy

Reviewed by:

Itziar Laka, University of the Basque Country, Spain
Ina Bornkessel-Schlesewsky, University of Marburg, Germany

Copyright © 2014 Miyagawa, Ojima, Berwick and Okanoya. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Shigeru Miyagawa, Department of Linguistics and Philosophy, Massachusetts Institute of Technology, 32D-808/14N-305, Cambridge, MA 02139, USA e-mail:

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