APA Dictionary of Psychology

a theory of female mate selection proposing that certain male traits with little or no survival advantage are nonetheless so sexually attractive to females that they choose mates with these traits and thereby ensure male offspring with the same attractive traits. The theory attempts to explain the rapid (runaway) evolution of disadvantageous male traits in some species (e.g., the long, colorful, but cumbersome tails of peacocks). Compare good genes hypothesis. [proposed by Ronald Aylmer Fisher]