Each other.

All that "social goo," as longtime teacher Dorothy Works put it, can gum up the learning process.

"It had occurred to me many, many times," Works said. "What if we could just split up boys and girls, and knock out all that daily drama?"

So in January, Works and three other teachers with whom she works closely at Carrboro's McDougle Middle School decided to try it. Since then, their 100 or so seventh-graders have been split by sex into separate classes for the core subjects: math, language arts, social studies and science.

Long a trademark of private boarding schools, the single-sex approach is getting a closer look from public schools. In 2004, the U.S. Department of Education loosened its guidelines on sex-based divisions, deciding that schools could hold single-sex classes as long as they are equal in quality, a clear rationale is provided and mixed classes also are held.

Some advocacy groups argue that it accelerates academic progress by acknowledging innate differences between the sexes and giving kids a less-distracting classroom environment. Research results have been less than definitive.

Opponents say that separate isn't equal and that single-sex classes leave students ill-prepared for the real world.

Participation

All Works knew was that she intended to retire next year after 31 years and was running out of time to test her theory.

But she and her colleagues didn't tell the superintendent or the school board, choosing to notify parents of the experiment in letters sent home Jan. 6, a Friday. They assured parents that the experiment would last a few months at most.

"We didn't want to run the risk of someone saying, 'No, no, no,' " Works said.

On Monday morning, to the dismay of a few student couples, they were split up.

"Honestly, I couldn't stand it at first," said Shaq Williams, 12. "I need to have some girls in my class."

But for the most part, the reluctance has faded into indifference, with some students embracing the split. The sexes still mingle during lunch and elective classes.

Some students who had never spoken up in class have become frequent hand-raisers, the teachers said. Works said they've noticed the strongest spike in girls-only science classrooms and boys-only language-arts classes.

"I like the way it's worked out," said Ashley Arroyo, 13. "I think all of us can concentrate better."

So far, parents haven't moved to shut the experiment down.

"I was a little surprised when I saw the letter," said Bob Stocking, a member of McDougle Middle's governance committee, whose son is part of the experiment. "I trust these teachers. If it was a disaster, they'd give it up. This hasn't really rocked the boat."

In fact, the McDougle Middle experiment is now being considered across town at Chapel Hill's Phillips Middle School.

Middle-school students are frequently grouped by learning ability and other factors, so separating them by sex wouldn't be a huge stretch, Phillips Principal Eileen Tully said.

"We've received a lot of positive feedback, some strong negative feedback," Tully said. "We're trying not to do anything too quickly."

Assumptions

Groups such as the National Organization for Women have likened classes split by sex to the unconstitutional "separate but equal" reasoning used to keep schools racially segregated.

"I really feel this is dangerous," said Anna Worthen, president of North Carolina's NOW chapter. "What if you're a little girl that doesn't learn the 'girl way'?"

Teachers should challenge assumptions about sexes, she said, not cater to them.

"When kids say science is for boys, that's just what society has told them," said Worthen, who works in the technology field mostly around men. "If I had not learned to interact with men, how could I go into my workplace and encounter them every day?"

More than 200 public schools in the United States have single-sex classes, according to the National Association for Single Sex Public Education, an advocacy group.

They've counted six in North Carolina -- Statesville, Wilson, two in Elizabeth City, and two entire schools in Greensboro (under a special provision) -- but others are out there, including the Carrboro classes.

The N.C. School of Science and Mathematics, a state-run boarding school in Durham, started a computer-focused class for girls last year.

Those schools are trying what Saint Mary's School in Raleigh has done for more than 160 years as a girls' boarding and day school.

Splitting the sexes acknowledges what "educators have known for years," said the head of Saint Mary's, Theo Coonrod. "Boys and girls learn differently. We know that girls respond to more collaborative learning. The boy brain seeks competition."

Advocates of single-sex classrooms, such as Coonrod, say math, science and technical classes are much more attractive to girls when boys aren't around to be an intimidating factor.

So, when do the Saint Mary's girls get to socialize with boys?

"After school and on the weekend, they seem to have no problem finding each other," Coonrod said.

On Tuesday morning, Works circled 22 girls, prepping them for a state-mandated writing test in March. Heads of shoulder-length hair hovered close to notebooks. When it was time for questions, skinny arms went skyward.

This experiment will end sometime before school lets out in June. At that point, Works and her team will look at how grades have changed. They've already started to improve, Works said.

"Just like we thought, they were hiding their strengths," she said of both boys and girls. "But this is just an experiment with 105 kiddos. It's not the wave of the future."