Handicap Principle - Generality and Empirical Examples

Generality and Empirical Examples

The theory predicts that a sexual ornament, or any other signal, must be costly if it is to accurately advertise a trait of relevance to an individual with conflicting interests. Typical examples of handicapped signals include bird songs, the peacock's tail, courtship dances, bowerbird's bowers, or even possibly jewellery and humor. Jared Diamond has proposed that certain risky human behaviours, such as bungee jumping, may be expressions of instincts that have evolved through the operation of the handicap principle. Zahavi has invoked the potlatch ceremony as a human example of the handicap principle in action. This interpretation of potlatch can be traced to Thorstein Veblen's use of the ceremony in his book Theory of the Leisure Class as an example of "conspicuous consumption".

The handicap principle gains further support by providing interpretations for behaviours that fit into a single unifying gene-centered view of evolution and making earlier explanations based on group selection obsolete. A classic example is that of stotting in gazelles. This behaviour consists in the gazelle initially running slowly and jumping high when threatened by a predator such as a lion or cheetah. The explanation based on group selection was that such behaviour might be adapted to alerting other gazelle to a cheetah's presence or might be part of a collective behaviour pattern of the group of gazelle to confuse the cheetah. Instead, Zahavi proposed that each gazelle was communicating to the cheetah that it was a fitter individual than its fellows and that the predator should avoid chasing it.