According to the study, disruptive behavior may indeed be working against the wiggle worms of the world.

[Study co-author Jessica] Van Parys and co-researchers analyzed data from the National Center for Education Statistics involving about 6,000 mostly white, black and Hispanic students from around the country who were followed from kindergarten through fifth grade, starting in the 1998-1999 school year.

Students were given tests in reading, math and science, while teachers also rated students' abilities in all three areas, as well as rated them on classroom behaviors. The study found that when assessing kids' academic abilities, the teachers factored in their classroom behaviors.

This ultimately helped the girls and hurt boys. The girls scored about 15 percent higher in behavior (also called "non-cognitive skills"), which meant they earned better grades than boys, even though they didn't score as high on the tests.

"Our point is that teachers take into account other factors, either consciously or unconsciously, when they rate the child's ability on all kinds of subject areas," Van Parys said. "It's hard for teachers to be completely objective when they're giving an assessment."