It seems that it's a cliché for a reason: "nice guys finish last". Recent research has found that people with so-called dark personality traits - narcissism, psychopathy, and Machiavellianism - are rated as more attractive than their more ethical, less selfish peers. That finding validates just about everyone's middle school experience. But why is that true? A new study finds that those three traits, known as the "dark triad", are linked with an increased ability to successfully enhance a person's appearance. The study also suggests that people who possess the dark triad are more skilled at presenting and carrying themselves, which is why they are generally immediately liked.

Researchers Nicholas Holtzman and Michael Strube hailing from Washington University in St. Louis performed a study with 111 college students, 64 percent of whom were women. In order to test their level of attractiveness, each student was photographed shortly after their arrival at the research facility.

Afterwards, each person was asked to change into gray sweatpants. Women were asked to scrub make-up from their faces and anyone who had long hair was asked to tie it back in a ponytail. Researchers took a second picture of each participant in a natural state.

Then researchers gave both sets of pictures to strangers so that they could evaluate each participant's level of attractiveness. Holtzman and Strube were then able to determine how much each participant was able to improve upon their appearance with clothes, makeup, jewelry, and so on.

In order to assess participants' personalities, all volunteers were asked to rate themselves. The participants also furnished the email addresses of friends so that peers could assess their personalities as well. A combination of self- and peer-ratings was used to create each participant's personality score; narcissism, psychopathy, and Machiavellianism were combined as well to create a "dark triad" score.

Researchers found that, in general, the higher the dark triad score, the higher their physical attractiveness was rated in their "dressed-up" pictures. However, there was no relationship between their dark triad score and their "dressed-down" pictures, indicating that people with dark personalities are better at making themselves look physically attractive.

The study builds upon previous research linking negative personality traits, like narcissism, with increased likeability. One study performed in 2010 found that people who were more narcissistic were rated as more likeable after a brief round of introductions.

Whether we like it or not, people who are considered physically attractive also are assumed to be, at least initially, as kinder, smarter, and more confident. People with exploitative personalities also are seen as more confident and funny - leaving even better first impressions.

However, in long-term relationships, more humble people may be cheered at the fact that people steer clear from those with dark personality traits. These studies show the importance of waiting to form judgments about people.