For years blue-ribbon panels of experts have sounded the alarm about a looming shortage of scientists, mathematicians and engineers in the U.S.—making dire predictions of damage to the national economy, threats to security and loss of status in the world. There also seemed to be an attractive solution: coax more women to these traditionally male fields. But there was not much public discussion about the reasons more women are not pursuing careers in these fields until 2005, when then Harvard University president Lawrence Summers offered his personal observations.
He suggested to an audience at a small economics conference near Boston that one of the major reasons women are less likely than men to achieve at the highest levels of scientific work is because fewer females have “innate ability” in these fields. In the wake of reactions to Summers's provocative statement, a national debate erupted over whether intrinsic differences between the sexes were responsible for the underrepresentation of women in mathematical and scientific disciplines.
As a group of experts with diverse backgrounds in the area of sex differences, we welcome these ongoing discussions because they are drawing the public's attention to this important issue. In this article, we present an analysis of the large body of research literature pertaining to the question of female participation in these fields, information that is central to understanding sex differences and any proposal designed to attract more women to the science and mathematics workforces. Contrary to the implications drawn from Summers's remarks, there is no single or simple answer for why there are substantially fewer women than men in some areas of science and math. Instead a wide variety of factors that influence career choices can be identified, including cognitive sex differences, education, biological influences, stereotyping, discrimination and societal sex roles.
It does not take a Ph.D. to see how making fuller use of female talent would go a long way toward increasing the number of scientific workers. In the U.S., for example, women made up 46 percent of the workforce in 2007 but represented only 27 percent of those employed in science and engineering. One reason Summers's comment upset many people was its implication that any attempt to close this gap was futile. If most women are naturally deficient in scientific ability, then what could be done? But this seemingly simple interpretation contains two misconceptions.
First, there is no single intellectual capacity that can be called “scientific ability.” (For simplicity, we will often use the term “scientific” to refer to skills important to work in the fields of science, technology, engineering and mathematics.) The tools needed for scientific achievement include verbal abilities such as those required to write complex journal articles and communicate well with colleagues; memory skills such as the ability to understand and recall events and complex information; and quantitative abilities in mathematical modeling, statistics, and visualization of objects, data and concepts.
Second, if women and men did demonstrate differences in these talents, this fact would not mean these differences were immutable. Indeed, if training and experience did not make a difference in the development of our academic skills, universities such as Harvard would be accepting tuition from students under false pretenses.
One of the confusing things about the field of sex differences is that you can arrive at very different conclusions depending on how you decide to assess abilities. Women clearly have the right stuff to cut it academically. They have constituted the majority of college enrollments in the U.S. since 1982, with the attendance gap widening every year since then. Similar trends are occurring in many other countries. Furthermore, women receive higher average grades in school in every subject—including mathematics and science.
Despite their success in the classroom, however, women score significantly lower on many standardized tests used for admissions to college and graduate school. The disparity in male-female enrollment in science and related fields grows larger at advanced levels of the education system. For example, in the late 1990s women represented 40 percent of undergraduates in science at the Massachusetts Institute of Technology but only 8 percent of the faculty.