The honesty of animal communication is a hotly debated topic. Honest signaling assumes a correlation between an observable signal and a non-observable quality. How this correlation is achieved is the key question of reliable communication and the topic of debate. The handicap principle is still widely accepted and cited — in it is original form — as the main mechanism that maintains the honesty of signals under conflict of interest, even though it has been criticized on several accounts. In short, it claims that signals need to be costly in order to be honest, and that honest signalers have to pay this extra cost at the equilibrium (i.e., signals have to be handicaps; Zahavi). Honesty, however, is not maintained by the realized cost of honest signalers at the equilibrium but by the potential cost of cheating. Whether this potential cost implies a realized cost for honest signalers depends on the biological details of the system, and thus this cost cannot be predicted a priori without the knowledge of these details. Accordingly, depending on these details, signals need not be costly in order to be honest, not even under conflict of interest (i.e., honest signals need not be handicaps). In other words, handicapping equilibrium signals are not the only way to create high potential cost of cheating. In my talk I will first review the theoretical models supporting the above conclusion, and then discuss a number of such mechanisms that can maintain high potential cost of cheating without imposing extra realized cost (i.e. handicap) on honest signalers at the equilibrium.
Szabolcs Számadó wrote his Ph.D on the issue of the honesty of animal communication, which he studies by means of game theoretical modelling. He published several articles on this topic; most of them involve game theoretical models of basic biological interactions like aggressive communication, mate choice or parent-offspring communication. He is currently a senior research fellow and member of HAS-ELTE Research Group for Theoretical Biology and Ecology at the Eötvös Loránd University (Hungary, Budapest).