A couple of years ago, I was standing inside a coffee shop, fiddling with the condiments in front of the main window. At a table outside, an unbelievably gorgeous young woman, looking like Nicole Kidman's more voluptuous younger sister, was showing a middle aged man in a suit a large album of tasteful fashion photos of herself. Apparently, she was a professional model and the man was some kind of agent or editor.

"Whoa!" said the young man next to me, who looked like an unemployed bike messenger. "Check her out!"

"Yes, a beautiful girl."

"And she's got a lot of tattoos!" he exclaimed, with a wild look of excitement in his bloodshot eyes.

That struck me as, by far, the least of her charms. On further reflection, though, I assume that her tattoos signaled to him that, while you might think she wouldn't be interested in any fellow below the movie producer / hedge fund manager level, she was actually a really bad decision-maker. So, he had a chance!

You might think that a girl who wants to send that message to hungover guys who look like washed-up ex-motocross riders might find a less permanent way to advertise this fact (such as dress, make-up, or hairstyle), just in case she ever changes her mind and wants to raise her standards. But, in our culture, we have such a commitment to authenticity that countless women feel that it would be downright immoral to advertise their inherent sluttiness only part time. Hence, tattoos.