Ben Barres is a world-renowned neurobiologist, whose quiet demeanor is off-set by the twinkle of intensity in his eyes.
With an M.D. from Dartmouth and a Ph.D. from Harvard, Barres is a respected scientist who is known on the Stanford University campus as a great mentor, especially to women.
IN TOUCH: Send Your Video Comments
Barres, a staunch feminist, is deeply offended by the insinuation that women are less talented in science. That may be because Ben Barres spent 40 years of his life as Barbara Barres.
Growing up, Barbara Barres was a tomboy and math whiz who wound up at MIT, despite the fact that her high school guidance counselor discouraged her from applying there.
It was the 1970s, when only 11 percent of MIT's students were women, and Barres described the atmosphere as occasionally sexist.
Once, Barbara Barres solved an equation the professor had designed to stump the class, and was the only one who got it right. But the professor didn't believe a woman could solve the puzzle.
"He looked at me with sort of this disdainful look and said, 'Well, your boyfriend must have solved that for you,'" Barres recalled.
Barbara Barres didn't get credit. And yet, it was the accusation of cheating that got under her skin, not the blatant sexism.
"It was only years and years later that it occurred to me, 'Gee, this was sexism,'" Barres said.
It's possible the sexism didn't register because Barbara Barres never really identified with women. "I certainly did not feel comfortable wearing makeup, wearing jewelry. High heels, things like that, were agony," Barres said. Ironically, the only problem she couldn't solve was deeply personal.
As Barbara Barres in college, she dated only briefly, Barres said. "If anything, I have weak attractions to men. But I really don't have strong attractions to either sex," Barres said, describing himself now as a contented bachelor. His passion, aside from science, is roasting his own coffee, which fills his kitchen with a rich aroma.
Today Ben Barres seems comfortable in his skin, but his was a long journey toward self-discovery. It took a breast cancer scare and a mastectomy when Ben was still Barbara to make Barbara realize she'd been living in the wrong body for 40 years.
"I remember that my doctor was kind of horrified at my suggestion that he cut 'em both off while he was at it, and another doctor, a year later, saying, 'Well, don't you want to have reconstructive surgery now?' And I was like, 'No, I am not gonna let anybody put those things back on me.'"
It's been 10 years since Barbara Barres became Ben Barres, with hormones and surgery. And Barres' unique perspective has turned him into a fervent crusader in the debate over whether gender matters in science. In one of the first lectures after his sex change, Barres spoke at MIT.
"Afterward, somebody who was familiar with the work of Barbara Barres apparently was heard to comment, 'Gee, that Ben Barres' work is so much better than his sister's.'" The person said this, evidently not realizing that Ben and Barbara were the same person.
That's a telling anecdote about the way men and women are perceived in the field of science. "There is a presumption that work being done by a man is better than work being done by a woman," said Barres.
When former Harvard president Lawrence Summers caused a firestorm last year by suggesting that women are less innately talented in science than men, Barres called it verbal violence and felt he had to speak up.
"If people treat women as if they are less good, that treatment in itself causes them to be less confident, to choose to leave science," Barres said, adding, "I am always amazed when Larry Summers and others make this comment, because it so flies in the face of the data. A little bit less arrogance would go a long way."
In an impassioned response just published in the journal Nature, Barres references a slew of academic studies that found that women who applied for grants had to do more than twice as much work as men did, and that women at MIT were not getting equal resources, such as lab space.
His point: The gender gap in science has less to do with subtle differences in brain power and much more to do with bias.
Last week, a panel convened by the National Academy of Sciences said women in science and engineering are hindered not by lack of ability but by bias and "outmoded institutional structures."
The report recommends altering procedures for hiring and evaluating scientists, changing typical timetables for tenure and promotion, and providing more support for working parents.
Barres helps to fight bias by lending his hand to the respected Pioneer Award program, the National Institutes of Health's most prestigious prize. As a judge, he worked to make the application process more open, which led to important results.
Barres said the number of women and minority winners shot up from zero percent to nearly 40 percent. "The very best part was that we only discussed who was the best scientist and what was the best science."
And in Barres' perfect world, that's all that should matter.