"The peacock's colorful and elaborate tail requires a great deal of energy to grow and maintain. It also reduces the bird's agility, and may increase the animal's visibility to predators. The tail appears to lower the overall fitness of the individuals who possess it. Yet, it has evolved, indicating that peacocks with longer and more colorfully elaborate tails have some advantage over peacocks who don’t."
What is the human equivalent of the peacock's tail? Something that is selected due to some sexual preference, but that has no impact on the fitness of the male?