Because single-sex classes are a recent phenomenon in public schools, the jury is still out about whether they truly improve learning. Still, the early results are promising. Students in Carver Elementary's boys- and girls-only classes outperformed the district's coed pupils on standardized tests. In South Carolina, the state with the most single-sex public classrooms (164 out of its 1,173 K-through-12 schools offer it), 80 percent of parents whose kids attend boys- or girls-only classes credited them with improving their child's academic performance, according to a 2010 DOE survey. And their kids agree: 75 percent of those polled said that single-sex classrooms had helped their grades, their self-confidence, and their study habits.
Boys- and girls-only classes may also benefit students by helping to curb stereotypical sex roles. When girls and boys are placed together, they tend to be mindful of what the prevailing culture suggests is appropriate for their respective sexes--a phenomenon Dr. Sax calls gender intensification. That's one reason why you don't commonly hear boys in a coed class recite a Shel Silverstein poem or see girls going gaga (in a good way) over the solar system. Yet if you were to visit a girls' classroom, proponents like MacIsaac say, you're more likely to see girls participating enthusiastically in math, science, and computers; at a boys' school, you're more likely to see students avidly engaged in subjects such as art, music, and drama.
Aside from these advantages, many parents point out that their kids' manners improve after switching to a single-sex class. That likely has more to do with the classroom dynamic than anything else. At Carver Elementary, "Mealey's Men" and "Mulcare's Ladies," as the first-graders dub themselves, follow a strict code of conduct that emphasizes kindness, respect, and responsibility. Tom Mealey's students know to stand when an adult enters the room and to use "Mr." and the person's surname when addressing each other. "Brody impressed people at a wedding recently by shaking the adults' hands, making eye contact, and acting like a total gentleman, which he learned from being in Mr. Mealey's class," says Julie Bjellos, whose son turns 10 this month.
But not everyone is convinced that single-sex classrooms are a good thing. A recent study in the scholarly journal Sex Roles found that the public-school students who joined a girls-only middle school tended to be academically advanced already. This may be because high-achieving children and their parents are more likely to choose a classroom setting that they feel will give them an edge or because the school administrators selected students for admission so their single-sex program would succeed, notes Rebecca Bigler, Ph.D., one of the study's researchers and a psychology professor at The University of Texas at Austin.
Beyond this, some experts caution that separating classrooms by sex in grade school may hurt kids' social skills in the long run. "Losing out on the opportunity to interact with the opposite sex during a child's formative years can make it more difficult to communicate in relationships later on," says Lise Eliot, Ph.D., a neuroscientist and the author of Pink Brain, Blue Brain. But since boys and girls in single-sex classes at public schools still commingle at lunch, recess, and on field trips, that last concern may be overstated.