Mystery of the Missing Women in Science Peter Ostrander, the tireless coordinator and cheerleader for a renowned science and mathematics magnet program at Montgomery Blair High School in Silver Spring, Md., was not satisfied. Over the past few years, the pool of applicants had included nearly as many girls as boys, and the acceptance rate - based largely on test scores and grades - had followed suit. Yet when it came to which of the invitees ended up choosing Blair's magnet option over other offerings in the area, the scales tilted male. In 2012, for example, 80 percent of the eligible boys said yes, but only 70 percent of the girls. In 2010, the figures had been 93 percent and 56 percent. Convinced the program could do better at pitching its product to girls, Mr. Ostrander recruited teams of upper-class girls last spring to call their hesitant young counterparts. Extol the wonders of the program, he said. Dispel the tired geek myths. "The stereotype is out there that the magnet is filled with nerdy people," he said. Whatever that means. The upper-class students took to the phone banks with verve. Full disclosure: my daughter was one of them. They talked of fun, extracurriculars and sisterhood. They secured many yes votes and earned pizza and sandwiches - but still, fewer qualified girls than boys are entering the magnet this fall. As a result, the demanding, gratifying, even thrilling four-year immersion in physics, chemistry, biology, calculus, computer science, astronomy, entomology, the proper use of power tools - and yes, the humanities and social sciences - remains almost two-thirds male. Montgomery Blair's experience is by no means unique. Even as girls prove their prowess in science and math, their ambivalence lingers when it comes to fields formerly painted boy blue. As researchers see it, that reluctance, that slight and possibly subliminal case of unfounded quantipathy, must be confronted and understood if the wider inequities in science are to be rooted out for good. Ample evidence refutes the notion that female brains just can't rotate the object, leap the quantum, do the math. Worldwide, girls" average math scores are on a par with those of boys. And even among math geniuses who score in the top ten thousandth of the population - the rarefied precinct notoriously deemed a boys" club by the former Harvard president Lawrence Summers - the male advantage has been shrinking steadily, to about 3 boys per girl today from 13 in the 1980s. Joseph Price of Brigham Young University and his colleagues reported this year that the gender gap in high-stakes math competitions disappeared simply by adding more rounds to a contest. Boys did better than girls in single-shot events, the researchers said, but when put through multiple rematches the boys fumbled, allowing the girls to catch up and often surpass them. Girls also excel in the classroom. Nationwide, their grade point average in high school math and science is 2.76 out of 4, compared with 2.56 for boys. The message of equal aptitude has certainly infiltrated today's youth. In a recent presentation at a meeting of the American Psychological Association, Anthony Derriso of the University of Alabama reported his analysis of a vast 2009 study of more than 21,000 ninth graders nationwide. Mr. Derriso, who is completing his doctoral dissertation in psychology, determined that students of both sexes rated boys and girls equally competent in science and math; expressed similar levels of confidence in their own math and science skills; and were equally likely to say they felt they were engaged in math and science and were supported by their teachers, parents and peers. Yet aptitude is one thing, aspiration another. In answer to the question "Are you likely to pursue a scientific career?" some 2,300 students - 11 percent of the total - said yes. Among the ninth-grade yea-sayers, 61 percent were male. Mr. Derriso admits to bafflement. "If boys and girls are equally interested in math and science and feel equally confident about their abilities," he wondered, "why this humongous difference in intent? I don't have an answer for that. The division marches off to college. Connie Chow, the executive director of the nonprofit group Science Club for Girls, pointed out that 29 percent of male college students major in math or science, compared with only 15 percent of female ones. Boys who ace science embrace science, but female mathletes keep their skills at arm's length. Researchers have found that, among students with high scores on the math portion of the S.A.T., boys cited their desire to major in the physical sciences, engineering or computers, while the girls preferred fields like economics, political science or medicine. One reason for the disparity may be that girls with high math scores, unlike their male counterparts, also tend to have high verbal scores and so may feel their career options are wide open. But still, given the choice, why do so many girls walk away from science and math?