In a recent study from the University of Missouri, "the comments your Facebook friends leave on your profile picture strongly affect your level of perceived physical, social and professional attractiveness." As Seoyeon Hong, a doctoral candidate in journalism, adds that the more comments, especially positive ones, a person receives, "the more attractive they’re perceived to be."
"People tend to rely more on other-generated information than self-generated information when forming impressions,” Hong says. “In other words, opinions of other people matter more than the target person’s own self-presentation. Thus, for social networking users concerned about forming a desired impression, being aware of other-generated information about oneself is paramount in the goal of achieving a positive self-presentation.”
Surprisingly, the study also pointed out that pictures of people playing sports or a musical instrument received more positive feedback than head shots. Maybe you'll think twice about what profile picture you put up on Facebook now, right?