The Cost Is the Point

Why would females favor a trait that endangers the male? One influential idea, Amotz Zahavi's handicap principle, proposes that only a genuinely fit male can afford such a wasteful display, so the burden itself acts as a hard-to-fake badge of quality. It is an elegant suggestion, but a contested one: many biologists now argue that a signal need not be costly to stay honest, and the field increasingly favors models where honesty is kept in check by the trade-offs a male faces — what a weak male would lose by bluffing — rather than by the price of the display alone.