Nature vs. nurture divides academia

Academia has been bitterly divided by the nature vs. nurture debate, and the Harvard president's comments last month at a National Bureau of Economic Research symposium touched on aspects that are so controversial that the opposing sides almost never discuss them.

On one side are those who believe the sexes are equal enough in their intellectual abilities that any biological difference is vastly outweighed by social pressures and discrimination that discourage girls and women from pursuing science and engineering.

''When people hear 'biology,' they think there's nothing you can do about it," said Joshua Aronson, a professor of applied psychology at New York University. ''It's in that context that Summers' remarks are not helpful."

But there are those who believe that biological differences between men and women really can account for at least some of the underrepresentation of women in engineering and some fields of science. They say more research could shed light on how individuals overcome differences to accomplish what they do.

''I think it's an outrage that certain questions -- that real, important questions -- can't be raised in an academic atmosphere, that research that's well-known can't be presented without some sort of hysterical response," said Linda S. Gottfredson, a psychologist at the University of Delaware.

In recent years, neuroscientists have found that male and female brains are wired differently because of the role of testosterone and other male hormones during gestation. Brains growing under the influence of male hormones are slightly larger and have denser concentrations of neurons in some regions.

Male brains also contain a greater proportion of gray matter, the part of the brain responsible for computation, while women have relatively more white matter, which specializes in making connections between brain cells.