Have you ever had the feeling that someone was looking at you? A new study says you may be so beautiful that people can't help but stare.

The study, conducted by Jon Maner, assistant professor of psychology at Florida State University, tested 440 heterosexual college students to see how long it took them to focus on an attractive face.

Participants were shown images of both highly attractive and average faces on a computer screen, then asked to shift their attention to a circle that was flashed somewhere else on the screen.

On average, all participants focused on the highly attractive faces within the first half second of seeing them.

The same participants took longer to shift their concentration away from the images of attractive faces than the average ones.

The study found that both men and women opted to stare at the attractive face, regardless of the face's gender, longer than the average face.

Single students immediately focused their stare on members of the opposite sex.

Students in relationships did the same with one small difference: They also focused on members of the same sex.

In addition, men in committed relationships were more likely to focus their gaze on someone of the same gender than committed women.

According to Maner's study, these tendencies are a result of biological evolution.

The involuntary reflex to stare at attractive faces of both sexes stems from the instinct to find a mate and to be able to guard him or her from competitors.

"Males are generally competitive with other males," said Jeffrey A. Kurland, associate professor of biological anthropology and human development. "It is a feature that defines our species. Males are more engaged in guarding a mate."

This practice isn't exclusive to men, however.

"When I had a boyfriend, I would catch myself staring at other girls," said Lauren Parrish (senior-human development and family studies).

"I would always find myself sizing up the competition."

Kurland said a symmetrical face is universally the most attractive facial feature.

"Both males and females are sensitive to how symmetrical a face is," Kurland said.

"Not to the point that someone looks like a robot, but a well-balanced face is important to both of the sexes."

In men, the study states that attractive features are usually connected with testosterone markers like a wide jaw and wide-set eyes.

In women, the most attractive features instead include signs of youth such as a high forehead and big eyes.

"I notice a girl's eyes and smile first," Kevin Sheaffer (sophomore-turfgrass science and agribusiness management) said, "but I'm not sure exactly what makes someone attractive."

Andrew Marenco (sophomore-business) said it's common sense that the human brain has an involuntary response to the presence of a good-looking person.

"It's hard not to look at a pretty face," he said.