Signal detection theory and noisy communication

Signal detection theory (SDT) has had little influence on thinking about the evolution of animal communication, despite its wide application in psychology. SDT is a model that describes the detection of signals in the presence of noise, a situation that clearly applies to animals that communicate in aggregations, such as many frogs and singing insects. Through SDT we can better understand fundamental issues about the evolution of communication. In many realistic signaling conditions receivers are unable to avoid making an error of one sort or another regardless of the criterion they use for responding to signals. Signals that are more exaggerated would be more detectable and receivers would be more likely to respond to these signals than to those that are less exaggerated and less detectable. Signal detection theory therefore provides a sufficient explanation for the exaggeration and elaboration of male displays used to attract females for mating. Moreover, principles of SDT apply to any communicatory interaction. Thus, SDT establishes universal conditions that any hypothesis regarding the evolution of signals must satisfy.