Grafen notes that there are at least four approaches to the handicap principle. These can be called the Qualifying Handicap (any male who has survived in spite of his handicap must be pretty good in other respects, so females choose him); the Revealing Handicap (males perform some onerous task in order to expose their otherwise concealed abilities); the Conditional Handicap (only high-quality males develop a handicap at all); and finally Grafen’s preferred interpretation, which he calls the Strategic Choice Handicap (males have private information about their own quality, denied to females, and use this information to ‘decide’ whether to grow a handicap and how large it should be). […] But males are assumed to have genes that are switched on conditionally upon the male’s own quality (and privileged access to this information is a not unreasonable assumption; a male’s genes, after all, are immersed in his internal biochemistry and far better placed than female genes to respond to his quality). Different males adopt different rules. For instance, one male might follow the rule ‘Display a tail whose size is proportional to my true quality’; another might follow the opposite rule.

Richard Dawkins, The Selfish Gene, 30th Anniversary Edition, 2006

Added to diary 27 June 2018