The lessons of relationship that our primordial ancestors learned are deeply encoded in the genetics of our neurobiological circuits of love. They are present from the moment we are born and activated at puberty by the cocktail of neurochemicals. It’s an elegant synchronized system. At first our brain weighs a potential partner, and if the person fits our ancestral wish list, we get a spike in the release of sex chemicals that makes us dizzy with a rush of unavoidable infatuation. It’s the first step down the primeval path of pair-bonding.
We want to look desirable. We want others to want to mate with us. No different than a colorful peacock. When girls dress up for their night out at the club, they are doing what all animals do when they try to make themselves desirable for a potential mate. That's the whole point behind the fashion, perfume, cosmetics, diet, and plastic surgery industries.
The red lipstick? It's supposed to signal fertility and readiness to mate. Just like the swollen red butt of a baboon. That tight-fitting little dress that shows off your curves? From the standpoint of evolutionary biology, big breasts represent a healthy mate who can feed a lot of offspring. That's why men are programmed to like big tits. When you show off your curves, what you're really doing is advertising to the whole world: "Look at me! I'm a healthy female! I'd be a perfect mate! Come mount me!
Human material culture - the buildings and roads and works that would strike any human as an obvious sign of intelligence - had for years seemed like part of an elaborate mating ritual to the starlings, useless and flamboyant as the peacock's tail.