“There’s no stereotyping. ... They assert themselves more, and that takes a part when they enter the work force,” she said.

At Charles Drew Elementary in Pompano Beach, classrooms are decorated with colors designed to make each gender more comfortable – blues for boys, yellows and reds for girls. Both genders are given occasional “brain breaks.” For girls that might mean five minutes to chat with classmates. For boys, it might mean a chance to wiggle around a bit.

Charles Drew and the other five Broward schools — Dillard and Martin Luther King elementary schools and Boyd Anderson, Everglades and Nova high schools — are participating voluntarily, as are the parents. Charles Drew Principal Angeline Flowers hopes separating the boys and girls will boost their achievement – particularly in reading. She said about 15-30 third-graders are held back each year.

Dr. Leonard Sax, who heads the National Association for Single Sex Public Education, said the big difference between boys and girls is not how they think or learn, but what they want to do.

“In other words, the biggest differences are not in cognition or ability, but in motivation,” Sax said.

He points to various studies on single-gender education and others on how the physical setting, like different types of lighting, can affect learning for boys and girls. One study, by a professor at Stetson University, found that over four years at Woodward Avenue Elementary in DeLand, Fla., 55 percent of boys in a co-ed classroom passed the FCAT, while 85 percent of boys in the all-boys classes passed.

“Some kids do better in coed. Some kids do better in single gender,” Sax said, adding that parents should have both options.

Fewer than half the parents at Charles Drew decided to enroll their child in single-gender classes, Flowers said, and so far, only one parent changed his mind.

With a laugh, Flowers recalled that dad’s reasoning for his third-grader: “ ‘My son needs to see some girls,’ ” he told the school. “ ‘And be motivated by some girls.’ ”

So far, the experiment at Charles Drew is limited to third through fifth grades, and the district is focused on analyzing test data to see if there are learning gains.

Teachers like Dwayne Lafavor are enthusiastic about trying something new.

“It made my teaching career go to another level,” said Lafavor, who teaches an all-girls fourth-grade class.

Lunch in the cafeteria is still co-ed, as are the occasional multi-class learning assignments. Similarly, the Young Men’s and Young Women’s academies hold prom and participate in co-ed competitions and social activities.

Rebekah Cadestin, a 10-year-old in Lafavor’s class, says she loves not having the boys around. Her classmates are more helpful, and she’s more comfortable sharing stories – like the one about a big blue icky bug at her house.

“I was so scared, I couldn’t even get ready for school,” Rebekah said. But tell that story to the boys, she said, and “they call us scaredy-cat.”

Broward officials are open to expanding their single-gender classes and also hope to study one of the biggest criticisms of such environments – namely, that they stunt social growth. Broward is collaborating with Stetson University to explore a potential five-year, grant-funded study. The goal: examine the before-and-after characteristics of single-gender students, including social skills.

At Young Women’s Prep, leaders and teachers say the recipe for the academic success has many ingredients: a smaller student body of about 400; a focus on math, science and technology; strong but caring teachers; older students mentoring younger girls; and, of course, no boys.

Lisette Clavell, the lead teacher and recruiter, said she sees a marked difference from when she taught at a large co-ed high school, John A. Ferguson.

“I remember five minutes before the bell at Ferguson everyone was putting on lip gloss, brushing their hair. The boys could care less, but the girls were all primping up. And you don’t see that here. They’re listening to what you have to say right up until the bell rings,” she said.

At the Young Men’s academy, the principal says students are more likely to take risks -- like taking the stage in drama -- and more than 90 percent of its graduates have been accepted into college.

But at just over 140 students, enrollment is weak. It’s difficult to recruit boys. There are no sports on campus. The district doesn’t provide transportation.

Even without girls around, boys at Young Men’s still think about them. “Whenever I sit down, I look beside me and I’m like, ‘There’s another guy,’” said Josiv Flores, a senior . “And I look the other way and oh, what do you know? Another guy.”

But at 17, he’s taking the long view: “There are no girls now, but in the long run, you’re still going to college, and in college there are going to be girls. Most colleges, the ratio from guys to girls is outstanding.”