The Peacock Effect
Note: This article is about the evolutionary effect called the Peacock effect, also known as Sexual Selection. It is not about the attraction technique of the same name (although the two are admittedly related and I have added a small section about the attraction technique at the end of the article)
Ordinarily, natural selection operates purely on things beneficial to survival. Things like strong muscles, healthy immune systems, sharper claws and thick shells. However, there is an interesting offshoot to this called Sexual Selection that operates on things that are only beneficial to reproduction.
The poster boy for Sexual Selection is the peacock, and another name for Sexual Selection even shares his name, the Peacock Effect. But the peacock himself doesn't do the selecting. His rather dull girlfriend, the peahen, does, and effectively her genetically determined preferences in males has led to the peacock of today over evolutionary time.
The peacock is so resplendent that he even appeals to human aesthetic sensibilities, with his bright colours and long, pearlescent feathers.
You might be wondering why it's the females who do the selecting and not the males. Why are the females so picky while the males are complacent with taking any mate, no matter how drab and boring she may look? The reason is that for a male, the commitment is merely a few moments of mating. For a female, the commitment involves carrying eggs and laying them, and roosting on them until they hatch. This is a big time commitment for her, and she wants the best male to be the father of her babies, so that she knows they will be beautiful and strong like he is.
But why is being beautiful an advantage? One theory is that the more colourful a male is, the more he will stand out to predators. This is of course a huge disadvantage to the male! But if a male manages to be bright and colourful and survive being hunted by predators, then this proves to the female that he must be a very strong and healthy individual, and fit to be the father of her chicks.
Some interesting experiments have been conducted on peacocks. The experimenter cut many feathers off the tail of a peacock, and added extra feathers to the tail of another to see how the females would react. The females went crazy for the male with extended feathers, but rejected the male with the broken feathers. This shows us for certain that evolving to have larger feathers is a big advantage for a peacock, because not being able to attract a female means not passing on his genes! As far as natural selection is concerned, living a long life is the same as dying young if you don't pass on your genes.
Perhaps you're wondering about attraction technique I mentioned earlier. How does the Peacock Effect apply to humans? Human societies have norms of fashion. While those norms can vary wildly between different places and different times, within each culture, the easiest way to fit in is to adhere to the norms. But merely fitting in doesn't allow one to stand out! A person who wears an unusual item of clothing is taking a risk. People may reject him for not fitting in. This is the last thing a person wants, to be a social outcast. However, If the person is still able to show himself to "fit in" then he will have added social proof! He is able to survive "predation" despite his lack of social "camouflage". This can be a very attractive quality!
So that's the Peacock Effect, in a nutshell. I hope you've enjoyed reading.