The number of public schools experimenting with single-sex education is still small but has shot up in recent years - from five to at least 241 in the last decade - as districts in more than half the states take the chance that separating boys and girls will help students learn better.
New guidelines expected soon from the U.S. Department of Education could help ease legal snags that have kept even more schools from trying single-gender programs.
The department's final guidelines are expected to clear up a conflict between the 2001 No Child Left Behind Act, which condones single-sex education, and the rules enforcing the 1972 Title IX law that banned sex discrimination in federally funded programs, including public schools and college sports programs.
"The current regulations say in no uncertain terms that co-ed schools cannot institute single-sex classes except in very narrow circumstances," said Emily Martin, the deputy director of the Women's Rights Project of the American Civil Liberties Union (ACLU). "It's true the Bush administration has proposed changes, but those changes haven't been finalized. They're not the law."
The threat of a lawsuit shut down a plan by Louisiana's Livingston Parish school system to pilot gender-separated classes at two middle schools this fall. The plans were shelved in August when the ACLU sued on behalf of 13-year-old Michelle Selden. "I don't agree that all girls learn one way and all boys learn another way," she said in a statement.
But potential lawsuits haven't deterred other schools. At least 33 states have public schools or classes that are gender-exclusive, according to the National Association for Single Sex Public Education (NASSPE), which maintains a list of programs. Ohio and New York lead with 10 single-gender public schools each. Indiana has at least seven schools, which all have opened in the last 14 months, while Pennsylvania follows with five and has another planned for August 2007.
South Carolina, Texas and Kentucky each have at least one single-sex public school, as well as at least 15 co-ed schools with classes split by gender. Private schools have always been allowed to offer schools and classes exclusively to boys or girls.
Title IX sharply limited gender-exclusive classroom programs, prohibiting separating the sexes at co-ed schools, except in choir, sex-education courses and physical-education classes where students had close contact, such as wrestling.
But then the 2001 No Child Left Behind Act (NCLB), which aims to have all children reading and doing math at grade level by 2014, allowed federal money to be used for innovative programs such as all-boys' and all-girls' schools and classes.
Because the two laws contradicted, the NCLB act directed the Department of Education to amend Title IX regulations and give school districts guidelines so they could set up sex-segregated programs without fear of being sued.
The education department proposed guidelines in 2004 that would allow gender-separated classes in co-ed schools if they are voluntary and have a comparable co-ed class. The proposals also made clear that districts could offer a school for one sex without offering a school for the other.
These moves coincided with the release of "brain-based" research, sometimes based on animal behavior, that showed boys and girls have inherent differences that also make their learning styles different. For example, said physician and NASSPE director Leonard Sax, girls learn best while sitting and boys while moving. Girls' brains also respond better to detail and color, while boys are better at processing motion and direction.
If teaching methods are geared toward each gender's differences, classes split by gender could help break down stereotypes, Sax said, adding, "You can have girls who love to take apart computers and who love physics and engineering, and you can have boys who enjoy reciting poetry."
The studies and promise of flexibility touched off a surge of new single-gender schools. Of the 51 single-sex schools listed by NASSPE, 42 have opened or become single-gender since NCLB's passage. Sixteen of the schools enroll both sexes but separate them in all classes, 19 are all-girls schools and 16 are all-boys schools. Others schools experimenting with single-sex education apply it in some — but not all — courses or classes.
This year two states - which both already had co-ed schools with gender-divided classes - passed bills to pave the way for more.
Wisconsin's law will allow its districts to set up such schools or classes as long as there is a comparable program for the other gender.
Michigan had to amend state law, which prohibited public schools from dividing students on the basis of race or sex. Its law also requires that programs be set up for both genders.
All-boys and all-girls schools also have become popular because they're seen as a possible solution to the "boy crisis" - the declining performance of boys in public schools as compared to girls.
Three years ago, Woodward Avenue Elementary School in Deland, Fla., set up gender-divided classes for both boys and girls after school officials noticed a growing gap between the two, with boys falling behind. Since then, the program has expanded from three grades to six grade levels - K-6 - and test scores for all grades have increased. "Our gender classes are doing as well or better than the mixed classes," said Jo Anne Rodkey, the principal.
She said, though, that the experiment was combined with teacher training and an extra teaching hour, and that those programs also could have accounted for the improved scores.
Education Sector , a nonpartisan Washington, D.C.-based think tank, recently released a report that analyzed 30 years of national test results. It found that "with a few exceptions, American boys are scoring higher and achieving more than they ever have before. But girls have just improved their performance on some measures even faster."
Martin of the ACLU called the studies showing gender differences "pop science" based on anecdotes and animal studies that make "overboard generalizations."
Even if the studies are correct and there are basic differences between boys and girls, she said, "It's still the case that not all boys are average boys and not all girls are average girls. … And therefore creating education environments that require boys and girls to conform to a stereotype of how the average boys or girl acts … is really unfair to students."
But to Sax of the NASSPE, single-sex schooling is on the rise - and will increase even more once the Department of Education finalizes guidelines.
"The great majority of schools that have expressed interest, when they find out the legal situation, they back off," Sax said. "For every principal or superintendent who says, 'I will do this even though it is prohibited,' there are 10 who say, 'Call us when the new regulations are out, and then we'll talk.'"