A study conducted by students at the University of Missouri found that the type of picture posted as your Facebook profile picture directly impacts a person's social and physical attractiveness. According to the results of the research positive comments and social cues are very beneficial to the perception tied to a user's virtual and real-world life.
"People tend to rely more on other-generated information than self-generated information when forming impressions," said Seoyeon Hong, a doctoral student in the University of Missouri School of Journalism. "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."
There may be those who simply do not care how they are perceived by others, but if we remind ourselves that third parties, including possible employers are using Facebook these days to research job candidates, then it is common sense to make sure that a profile picture makes the best possible impression - as long as that profile is publicly accessible. Hong noted that "cues" that would tie a user to sports or music help to achieve a positive perception.