When 13-year-old Ben, an eighth grader, logs onto Facebook and finds out he’s been unfriended, it makes him sad. It’s not only that he may have been close to the person — sometimes he was — but because Facebook holds a stake in our everyday life, it’s part of our identity.

According to a study published this summer, the more you’re on Facebook the more emotional ties you have to different interactions on the social platform. Jennifer Bevan, a professor at Chapman University in California, authored the study on negative emotional responses to being unfriended along with some of her undergraduate students, two of whom are listed as co-authors.

The group of students wanted to gear the study toward something they interacted with every day. Facebook fit the bill; being something almost everyone could relate to. The researchers found that the tailored identity you create and nurture on Facebook is what makes the process of being unfriended so hurtful.

It hurts most when users felt they were unfriended because they of something they’d done on the social network, though the study showed Facebook users are usually unfriended because of offline-related events.

Why does this matter so much? “I think it’s a testament to how important our Facebook identity is,” Bevan told Mashable.

Our digital avatars are changing the way we relate to each other and reflect typical social interactions. Peer aggression in the form of exclusion has been around since AOL’s Instant Messanger Buddy List, Nancy Willard, author of “Cyber Savvy: Embracing Digital Safety and Civility,” told Mashable.

But what causes one to unfriend a friend? There are several reasons to justify removing someone from your friend list. WIllard offered one possible scenario.

“My daughter has unfriended people because she does not want to have people judge her negatively based on the friends she keeps,” she said. “So when she unfriended a girl who was posting sexually provocative images, this was done for a very good reason.”

Other reasons for unfriending are excessive status posting, someone who is seen as dramatic or to avoid being influenced by someone else’s lifestyle choices.

Dr. Bevan, the researcher, admits there isn’t much research as of yet into this field of online interaction.

“You’re basically manipulating that relationship,” she said when asked if the effects of unfriending can be seen as malicious. “I think there needs to be more cyberbullying research.”

Ben tells us he has about 200 friends on Facebook, though he doesn’t check them daily. That doesn’t mean the social network isn’t the first thing he checks in the morning.

“Facebook is the next step down from the real world for us,” he said.

Have you ever been unfriended on Facebook or other social networks? How did it make you feel? Let us know in the comments.