Cost and conflict in animal signals and human language

Michael Lachmann, Szabolcs Számadó, Carl T. Bergstrom

Research output: Contribution to journalArticle

172 Citations (Scopus)


The "costly signaling" hypothesis proposes that animal signals are kept honest by appropriate signal costs. We show that to the contrary, signal cost is unnecessary for honest signaling even when interests conflict. We illustrate this principle by constructing examples of cost-free signaling equilibria for the two paradigmatic signaling games of Grafen (1990) and Godfray (1991). Our findings may explain why some animal signals use cost to ensure honesty whereas others do not and suggest that empirical tests of the signaling hypothesis should focus not on equilibrium cost but, rather, on the cost of deviation from equilibrium. We use these results to apply costly signaling theory to the low-cost signals that make up human language. Recent game theoretic models have shown that several key features of language could plausibly arise and be maintained by natural selection when individuals have coincident interests. In real societies, however, individuals do not have fully coincident interests. We show that coincident interests are not a prerequisite for linguistic communication, and find that many of the results derived previously can be expected also under more realistic models of society.

Original languageEnglish
Pages (from-to)13189-13194
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number23
Publication statusPublished - Nov 6 2001

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'Cost and conflict in animal signals and human language'. Together they form a unique fingerprint.

  • Cite this