Jacob Chisausky, Carl Bergstrom, Kevin Zollman, Graeme Ruxton

Honest communication is a common phenomenon in animal behaviour, and is frequently explained by appeal to the so-called handicap hypothesis by which signal costs deter dishonesty. However, the handicap models commonly used to explain honest signalling have has been subject to several lines of criticism in recent literature. This trend may have led researchers outside of the field of animal communication to believe that the handicap hypothesis is logically invalid. That is untrue. Here we explain the handicap hypotheses and explore these critiques in non-mathematical terms in order to more widely disseminate a contemporary understanding of the theory of honest signalling. We address what is currently known and unknown in signalling theory, and suggest directions for future research.