...of displays, gestures and ritual behaviour in animals. I quote Dawkins from Viruses of the mind: "Zahavi suggests that peacocks, for instance, evolve their absurdly burdensome fans with their ridiculously conspicuous (to predators) colors, precisely because they are burdensome and dangerous, and therefore impressive to females. The peacock is, in effect, saying: ``Look how fit and strong I must be, since I can afford to carry around this preposterous tail.'' To avoid misunderstanding of the subjective language in which Zahavi likes to make his points, I should add that the biologist's convention of personifying the unconscious actions of natural selection is taken for granted here. Grafen has translated the argument into an orthodox Darwinian mathematical model, and it works. No claim is here being made about the intentionality or awareness of peacocks and peahens. They can be as sphexish or as intentional as you please. Moreover, Zahavi's theory is general enough not to depend upon a Darwinian underpinning. A flower advertising its nectar to a ``skeptical'' bee could benefit from the Zahavi principle. But so could a human salesman seeking to impress a client. The premise of Zahavi's idea is that natural selection will favor skepticism among females (or among recipients of advertising messages generally). The only way for a male (or any advertiser) to authenticate his boast of strength (quality, or whatever is is) is to prove that it is true by shouldering a truly costly handicap --- a handicap that only a genuinely strong (high quality, etc.) male could bear. It may be called the principle of costly authentication." What do u personally think about this? And what is the scientific consenses on this hypothesis [is it confirmed enough to be a principle, if not what observations would be necessary]? What are the alternative hypothesis?