Artificial Life VI

Evolved Signals: Expensive Hype vs. Conspiratorial Whispers

Jason Noble
School of Cognitive and Computing Sciences, University of Sussex


Artificial life models of the evolution of communication have usually assumed either cooperative or competitive contexts. This paper presents a general model that covers signalling with and without conflicts of interest between signallers and receivers. Krebs and Dawkins (1984) argued that a conflict of interests will lead to an evolutionary arms race between manipulative signallers and sceptical receivers, resulting in ever more costly signals; whereas common interests will lead to cheap signals or "conspiratorial whispers". Simple game-theoretic and evolutionary simulation models suggest that signalling will evolve only if it is in the interests of both parties. In a model where signallers may inform receivers as to the value of a binary random variable, if signalling is favoured at all, then signallers will always use the cheapest and the second-cheapest signal available. Costly signalling arms races do not get started. A more complex evolutionary simulation was constructed, featuring continuously variable signal strengths and reception thresholds. As the congruence of interests between the parties became more clear-cut, the evolution of successively cheaper signals was observed. The findings are taken to support a modified version of Krebs and Dawkins's argument.

Back to ALife6 Table of Contents / Keyword Index / Author Index / Meeting Schedule