In most classes, ask who wants to lead the chemistry experiments and count how many young men's hands shoot up.
Not at Oldfields School. In science labs here, young women take all the credit for creating green ooze, juggling beakers and showering unsuspecting schoolmates with disappearing ink.
It is indeed a girls' world on these 200 acres in Glencoe, where, in grades eight through 12, girls and young women from 28 states and nine countries run the science experiments, the student government, the athletic programs, the horse shows.
The institution will celebrate its 125th anniversary as a girls' boarding school this weekend, and the event has come at an opportune time. As an increasing body of research suggests that young women are being shortchanged in co-educational classes, educators are re-examining the potential benefits of single-sex education like the one offered by the prestigious school.
For generations, Oldfields headmasters have espoused the wisdom of this educational approach, which has drawn students such as Wallis Warfield Simpson, Rockefellers and the daughter of Jordan's King Hussein. It has been here -- amid the riding arena, tennis courts and fox-hunting countryside -- that young, predominantly wealthy women have made a tradition of crowning their school queen in May and graduating in snow white dresses.
"It's the lessons of leading and learning that one gets in a girls' school that puts one a few steps ahead. Girls are able to find their voices and discover their own competence in a way that never leaves them," says Whitney Ransome, executive director of the National Coalition of Girls' Schools in Concord, Mass.
Anita Megginson, senior class president of Oldfields, has an unusual perspective, having previously attended public high school.
"At my public school there were 30 people in each class," says the 17-year-old from Northeast Baltimore. "You could always hide behind someone, and the guys got more attention. But in these classes, there are only seven or eight people. Girls express their opinions more."
A recent report by the American Association of University Women (AAUW), based on hundreds of studies about the nation's public schools, proves her point. It found that girls receive less attention in the classroom than boys, are discouraged from taking advanced math and science classes and are subjected to gender stereotypes.
The irony, however, is that while this bias against young women is being acknowledged, the trend toward co-education is growing.
In the 1960s, 38 percent of the private schools were co-ed. By 1990, that number had risen to 79 percent, according to Margaret W. Goldsborough, spokeswoman for the National Association of Independent Schools, which represents more than 1,000 private, non-parochial schools.
"There's been a trend toward co-ed, but a lot of single-sex schools are thriving at the same time," she says.
In Maryland at least, single-sex schools have a long tradition, with Western High School being one of the few single-sex public schools left in the country, says Ms. Ransome.
Hawley Rogers, headmaster of Oldfields, believes the primary advantage of girls' schools is that they allow adolescent girls to gain self-confidence during a fragile stage in their development. "These are the crucial years where girls need to be nurtured," he says.
When Allison Downes was looking at schools, she specifically directed her search toward girls' institutions. "I can be more myself here," says the 15-year-old from Oxford who goes by the nickname Mop. "And in class I don't feel as timid."
Yet despite the school's efforts to show women how to lead, the ultimate authority on campus is a man -- and has been for most of its 125 years.
Mr. Rogers believes that philosophy more than gender matters in his position. "My attitudes are more feminist than a lot of women," he says.
Some educators also wonder whether separating young women from young men is the best way to prepare them for the future.
"Does it then put young women in an environment that is, in a sense, false? When they get to college, are they prepared to compete in a co-ed setting? . . . The answer depends a lot on the girl," says Anne Bryant, executive director of the AAUW in Washington.
Oldfields clearly isn't an option for everyone -- particularly since many parents can't afford the $18,500 tuition. Nine percent of the 180 students are minorities and 13 percent receive financial aid.
Kelly Garrels acknowledges she is among the elite. "I feel privileged that I'm able to experience this. I feel bad for the girls that can't. . . . Maybe somewhere down the line I'll be able to help them," says the 15-year-old who is from Westfield, N.J., which, she says, has been described as "a wealthy suburb of New York."
Her friend and fellow sophomore, Jennifer Widmer, says, "You have more money than the majority of the people, but it's being used well here. It's not like everyone sits around and says, 'What does your father do?'"
And these adolescents relish attending classes without primping for male students and competing in sports without being called "brutes."
"I can concentrate on my studies here, rather than worrying about my hair or my clothes," says Ms. Megginson, who will attend Carnegie Mellon University in Pittsburgh this fall.
Guys who date Oldfields students sometimes like the arrangement, too.
Ms. Widmer says of a former beau: "He liked it that Oldfields was all girls. He didn't have to worry about me meeting other guys and liking them better."