The term is Handicap principle and it's not quite the same thing. According to recent evolutionary theory the peacock's tail may serve as a mate attractor exactly because it's so obviously detrimental and unwieldy; it signals that the bearer has more than sufficient overall biological fitness to compensate even with this drawback. The term 'peacocking' is very popular among pickup artists and it's a similar concept: some of the most famous ones would wear top hats or feather boas to nightclubs and use them as conversation starters to approach women.