The
handicap principle is a
hypothesis originally proposed in 1975 by
biologist Amotz Zahavi to explain how
evolution may lead to "honest" or reliable
signaling between animals which have an obvious motivation to bluff or deceive each other. The handicap principle suggests that
reliable signals must be costly to the signaler, costing the signaler something that could not be afforded by an individual with less of a particular trait. For example, in the case of
sexual selection, the theory suggests that animals of greater
biological fitness signal this status through handicapping
behaviour or
morphology that effectively lowers this quality. The central idea is that
sexually selected traits function like
conspicuous consumption, signalling the ability to afford to squander a resource. Receivers know that the signal indicates quality because inferior quality signallers cannot afford to produce such wastefully extravagant signals.