Harvard President Lawrence H. Summers has triggered criticism by telling an economics conference Friday that the under-representation of female scientists at elite universities may stem in part from “innate" differences between men and women, although two Harvard professors who heard the speech said the remarks have been taken out of context in an ensuing national media frenzy.

MIT biologist Nancy Hopkins ’64 said she felt physically ill as a result of listening to Summers’ speech at a National Bureau of Economic Research (NBER) luncheon, and she left the conference room half-way through the president’s remarks.

“For him to say that ‘aptitude’ is the second most important reason that women don’t get to the top when he leads an institution that is 50 percent women students – that’s profoundly disturbing to me,” Hopkins said. “He shouldn’t admit women to Harvard if he’s going to announce when they come that, hey, we don’t feel that you can make it to the top.”

But Lee Professor of Economics Claudia Goldin, whose own research has examined the progress of women in academia and professional life, said she “was pretty flummoxed” by the negative response to Summers’ speech, which—in her view—displayed “utter brilliance.”

Summers spoke from a set of notes—not a prepared text—so a transcript is not available. But in an interview with The Crimson this evening, Summers said that his speech was a “purely academic exploration of hypotheses.”

Summers’ speech came against the backdrop of widespread faculty criticism this fall following reports that only four of 32 tenure offers made in Harvard’s Faculty of Arts and Sciences last year went to women.

Early in his speech, Summers noted that women remain underrepresented in the upper echelons of academic and professional life—in part, he said, because many women with young children are unwilling or unable to put in the 80-hour work-weeks needed to succeed in those fields.

“I said that raised a whole set of questions about how job expectations were defined and how family responsibilities were defined,” according to Summers. “But I said it didn’t explain the differences [in the representation of females] between the sciences and mathematics and other fields.”

Goldin, who herself prepared a memo Summers cited in his speech Friday, said the president “had mountains of research” on the subject, although he spoke extemporaneously.

Summers referred repeatedly to the work of University of Michigan sociologist Yu Xie and his University of California-Davis colleague Kimberlee A. Shauman, who have found that women make up 35 percent of faculty at universities across the country, but only 20 percent of professors in science and engineering.

Their analysis of achievement test results shows a higher degree of variance in scores among men than among women. According to Ascherman Professor of Economics Richard Freeman, an organizer of the conference, the research found that “there are more men who are at the top and more men who are utter failures.”

Summers suggested that behavioral genetics could partially explain this phenomenon.

Freeman and Goldin both said that after Summers’ mentioned the “innate differences” hypothesis, he explicitly told the audience: “I’d like to be proven wrong on this one.”

By that point Hopkins, a renowned cancer researcher who last year was inducted into the prestigious National Academy of Sciences, had left the conference room. She said she was concerned that it would be “rude” to get up midway through Summers’ speech, but “it was just too upsetting” for her to stay.