A study out of Roanoke College in Salem, Virginia has discovered a link between Facebook-stalking "romantic jealousy" and GPA. The participants, students who ranged in academic achievement, were asked to envision their responses to scenarios such as seeing a post on their signficant other's wall (from a member of the sex to which they are attracted) that reads "What are you doing later?"
Denise Friedman, the study's author, posits that "students with higher GPAs are often more conscientious, show greater self-control and tend to be perfectionists. The perceived infidelity likely upsets their attempts at perfection across the board." Sure, that makes sense (as well as somewhat clarifying why your 1.4 (unweighted)-scoring high school stoner boyfriend didn't seem to care when he caught you subtly smelling the back of Jared Levy's shirt in study hall). I also suspect it has something to do with Facebook making the quantification of relationships easier solely by virtue of the "relationship status" tab. Thank you, Zuckerberg.
Rather hilariously, the study also found that male students were made even more jealous if the sentence ended with a "wink" emoticon, while the jealousy level of female students given the same emoticon remained unwavering.