CAMBRIDGE, Mass. – The president of Harvard University prompted criticism for suggesting that innate differences between the sexes could help explain why fewer women succeed in science and math careers.

Lawrence Summers, speaking Friday at an economic conference, also questioned the role discrimination plays in keeping female scientists and engineers from advancing at universities.

The remarks prompted Massachusetts Institute of Technology biologist Nancy Hopkins – a Harvard graduate – to walk out on Mr. Summers’s talk, The Boston Globe reported. “It is so upsetting that all these brilliant young women (at Harvard) are being led by a man who views them this way,” she said.

Five other participants in the National Bureau of Economic Research conference also said they were offended by the comments. Four other attendees contacted afterward by the Globe said they were not.

Mr. Summers told the Globe he was discussing hypotheses based on the scholarly work assembled for the conference, not expressing his own views.

Conference organizers said Mr. Summers was asked to be provocative, and that he was invited as a top economist, not as a Harvard official. The two-day conference of the National Bureau of Economic Research drew about 50 economists to discuss women and minorities in science and engineering.

Mr. Summers declined to provide a transcript of his remarks, but he did describe his comments to the Globe.

“It’s possible I made some reference to innate differences,” he said. He said people “would prefer to believe” that differences in performance between the sexes are due to social factors, “but these are things that need to be studied.”