THE COST OF DISHONESTY

The handicap principle states that stable biological signals must be h onest and costly to produce. The cost of the signal should reflect the true quality of the signaller. Here, it is argued that honest signall ing may be maintained although the used signals are not handicaps. A g ame theoretic model in tile form of a game of signalling is presented: all the existing evolutionarily stable strategies (ESSs) are found. H onest and cheap signalling of male quality is shown to be evolutionari ly stable if females divorce the mate if it turns out that he has chea ted about his quality. However, for this ESS to apply, the cost of los t time must not be too great. The stability of the honest signalling i s based on deceivers being prevented from spreading in the population because they suffer from a cost of divorce. Under some fairly strict c onditions, a mixed polymorphism of dishonesty and honesty represents a nother possible ESS.