In a highly unusual move, the presidents of three leading universities issued a statement Thursday to challenge the views of Lawrence H. Summers, the president of Harvard University, on women and science.
Summers has apologized for his statements, in which he suggested that "innate differences" between men and women may be a reason why there are so few women in science.
The statement  by the presidents of Stanford and Princeton Universities and the Massachusetts Institute of Technology rejects that view.
"The question we must ask as a society is not 'can women excel in math, science and engineering?' -- Marie Curie exploded that myth a century ago -- but 'how can we encourage more women with exceptional abilities to pursue careers in these fields?' " the presidents wrote.
The presidents -- John Hennessy of Stanford, Shirley M. Tilghman of Princeton and Susan Hockfield of MIT -- are all scientists.
In their statement, they said that the suggestions by Summers about "innate differences" tend to "rejuvenate old myths and reinforce negative stereotypes and biases." They also noted extensive research about cultural and societal factors that discourage women in science.
The presidents called for renewed efforts to "tap the talent and perspectives of both the male and female halves of our population."
Wrote the presidents: "Until women can feel as much at home in math, science and engineering as men, our nation will be considerably less than the sum of its parts. If we do not draw on the entire talent pool that is capable of making a contribution to science, the enterprise will inevitably be underperforming its potential."