In Sarah Wise's section of a computer systems laboratory at the elite Thomas Jefferson High School for Science and Technology, the 18-year-old senior is the only girl.
That's a better ratio, though, than in 17-year-old David Banh's computational physics class at the Fairfax County school. It has only boys.
Abbie Des Rosiers, an 11th-grader, is the lone female student in an advanced computer class at Thomas Jefferson High School for Science and Technology.
(Photos Gerald Martineau -- The Washington Post)
There aren't any girls in the school's top mathematics class, either, the one with seven students who must be invited to enroll. Senior Rachel Miller, 17, who took algebra in fourth grade, was asked to join, but she decided biology would be more fun.
Ask teachers, administrators and students at Thomas Jefferson -- where about 55 percent of the 1,694 students are boys -- why such discrepancies exist in these classes, and they will say it has nothing to do with ability.
So what explains it?
"It's a fabulous conundrum," said Josh Strong, the school's division manager for science and technology.
The issue has new relevance since Harvard University President Lawrence H. Summers roiled the academic world last month by suggesting that the country's shortage of elite female scientists might stem in part from "innate" differences between men and women. Critics accused him of saying that women are not genetically capable of doing math and science as well as men; Summers said he was misunderstood.
The notion that girls and boys cognitively develop differently is hardly rocket science. "Any elementary teacher can tell you that a class with 15 boys and five girls is very different from a class with 15 girls and five boys," wrote Scott Hollinger, principal of McAuliffe Elementary School in McAllen, Tex., in an e-mail response to questions about the issue.
Young boys are more physical and seem more spatially aware at a younger age, while girls are more social and learn language faster, educators say. (Thomas Jefferson once was 65 percent male, and the admissions test was made more verbal, although other factors helped bring in more girls, and the challenge remains to bring in even more, according to Principal Elizabeth Lodal.) But because girls and boys develop differently on average, research suggests that they can be directed to develop in different ways.
"Experience matters," said Susan Levine, a psychology professor at the University of Chicago.
Harvard University Professor Kurt Fischer, who is director of the university's Mind, Brain and Education Program, said none of the developmental differences mean anything about actual abilities.
Teachers and scientists say that there are greater differences in learning styles within each sex than there are between the sexes and that any school or teacher that doesn't approach students as individuals is missing the mark.
At Thomas Jefferson, nobody says girls, in general, can't do what boys in general can do academically -- if they want to. "It's not an issue of innate capability," said physics teacher John Dell.
But in some subjects, it appears they don't want to. Although all Thomas Jefferson students are required to take computer science, the more advanced elective courses are heavily populated with boys, as are advanced physics, engineering and math, teachers and students say; biology and chemistry classes are more attractive to girls, as are the humanities.
Students, teachers and administrators attribute class enrollment to factors including personal interests and personality, levels of exposure at younger ages and the subtle -- and not so subtle -- stereotypical signals sent by adults.
Boys, for example, are more often exposed to computers and blocks at an earlier age than girls -- perhaps because they like them more, perhaps not -- and thus come early to engineering, a subject that requires early interest for proper sequential course enrollment, teachers said.
Girls are usually more social -- something Jan Taylor, an engineer turned school counselor at Thomas Jefferson, believes is "hard-wired" -- and physics and math are commonly seen as more individual pursuits. Biology, on the other hand, is usually seen as more collaborative, students said.
Boys, Dell said, are more generally programmed for conflict, and part of scientific endeavor is to challenge conventional wisdom with an argument. And boys don't mind being wrong as much as girls, both boys and girls said.
"I like to be safe rather than put myself out there," said 16-year-old junior Beth Martin.
Many girls find some classroom environments intimidating. Take, for example, the computer systems labs. All day, nearly all of the chairs are occupied by males. The teachers admit testosterone rules the room. The atmosphere "is intense," and many girls don't see the room as "friendly," said Strong, who is considering moving the computers to the back of the room to make it more welcoming to girls.
One traditionally male-dominated laboratory already has attracted more girls by taking "gender out of the classroom," said Rick Buxton, director of the prototyping laboratory, where students often use heavy equipment to build things.
Buxton stopped making assignments by sex -- "We stopped saying, 'You can't do that because of your size' " -- and banned profanity and off-color jokes. Now enrollment is split evenly.
"The girls began to see it as a safe place," Buxton said. "They like working with their hands as much as anyone else. Give them an environment they are comfortable in, and they will come."
It was one teacher's insistence on calling on boys more often than girls that helped lead to the creation in 2001 of Tomorrow's Women in Science and Technology, aimed at helping empower women at the school.
Now TWIST, along with two other organizations for girls, helps mentor young elementary and middle school girls.
Part of the goal is to help them overcome social pressures, which weigh more on girls. Lisa Marrone, 16, a junior, said in middle school she was torn between academics and not "having a reputation for being a bookworm." When she got to Thomas Jefferson, she realized she could be social and smart.
Dell said that critics might be looking at the whole issue of sex in science wrong. "Physics and math are traditionally lonely pursuits," he said. "Society places value in having a good pool of physicists and mathematicians. But just because the country has a desire to have this pool, that doesn't mean it is a natural choice for an individual."
The natural choice for Rachel Miller this year was to take a break from math. She took AP calculus as a freshman, multivariable calculus and linear algebra as a sophomore and complex analysis and differential equations as a junior.
While the boys on her math level joined the top class, she decided to take a break and have some fun. "High school," she said, "is a time to explore."