Anyone who has ever been a teenager knows that most middle school friendships don't last to the senior year of high school. You and your buddies drift apart and you make new friends, but why?

Amy C. Hartl of Florida Atlantic University led a study, which tracked 410 seventh graders, checking in with them each year up to their last year in high school. The researchers found that friendships formed in the seventh grade would rarely last — there was around a 1 percent chance of maintaining such a friendship.

The researchers concentrated on some key points that could drive a wedge in these friendships, such as sex, peer acceptance (popularity), physical aggression, and school competence. They found that friendships were almost guaranteed to end if you had a pal of another sex, differences in physical aggression was next, followed by academic performance, and last was popular versus unpopular.

“Dissimilarity disrupts relationship bonds," explained Brett Laursen, from FAU's Department of Psychology.

Still, any loss of friendship at this age can be painful during, even debilitating, said Hartl, “because they are going through cognitive and emotional changes at the same time that they are establishing independence from their parents."

It's an interesting study, which sheds some light on why the friends some of us had in elementary school suddenly drifted away. The researchers say in sixth grade alone, friendships are considered “highly unstable, because primary school friendship groups are transformed across the first year of middle school." If it takes you till the eighth grade to find new friends, that bond may become broken as well, as researchers say these friendships are usually too unstable to survive the transition to high school.

So, if you still have your buddy from middle school, consider yourselves the lucky ones.

Read more at Science Daily.

Photo Credit: Rick Diamond / Getty Staff