title: Why does costly signalling evolve? Challenges with testing the handicap hypothesis.
authors.affiliation: MTA-ELTE Theoretical Biology and Evolutionary Ecology Research Group and, Department of Plant Systematics, Ecology and Theoretical Biology, L. Eötvös University, Budapest, Hungary.
authors.forename: Szabolcs
authors.initials: S
authors.lastname: Számadó
authors.affiliation: Konrad Lorenz Institute of Ethology, Department of Integrative Biology and Evolution, University of Veterinary Medicine, Vienna, Austria.
authors.forename: Dustin J
authors.initials: DJ
authors.lastname: Penn
keywords: action-response games; animal communication; handicap principle; receiver psychology; strategic costs