Over the past 20 years, women have been actively encouraged to study the natural sciences and engineering. Then why is there such a high exit rate of women from science careers? Anne Preston, associate professor of economics at Haverford College in Haverford, Pa., addressed this question in a presentation entitled“The New Influx of Women Into Doctorate Science: Career Patterns,” which was delivered at the Annual Meeting of the American Association for the Advancement of Science, Feb. 13-18, 2003 in Denver, Colo.

Preston discussed results from an empirical study of 1800 science and engineering graduates of public universities between 1970-1990, and the major factors behind the occupational exit of women from the sciences.“Little attention has been paid to how well these women fare in the science workplace,” said Preston.

Statistics based on data from the 1980s show that the occupational exit rate of women from the sciences was consistently twice as high as the exit rate of men. More recently, in 1999, a study focusing on individuals under 30 whose highest degree was a bachelor of science and those under 34 who held a master's or a Ph.D. showed that women were one and a half times as likely as men to leave science. Preston described four significant reasons behind these exits: high rates of changing knowledge, family responsibilities, mentoring, and discontent with science.

Change is one of the most defining characteristics of the field of science, but it brings hindrances as well as benefits.“Change can be stressful to employees in a discipline with constant pressures to remain current with new developments,” said Preston.“Permanent exit becomes a way out for those who can't keep up.” In fields with low rates of knowledge growth, the probability of permanent exit for women was 10 percent, and 15 percent in fields with high rates of knowledge growth.

Women are still more likely than men to be limited by a spouse's career aspirations, and to accept a larger share of family responsibility. Preston found that the most difficult periods for balancing career and family occur at different stages for women and men with varying levels of career aspirations and education. Women with doctoral degrees encountered more obstacles early in their careers and marriages, because a typical career for Ph.D.s requires geographic flexibility. These women were more likely to be in a dual-career marriage and to be younger and less established than their husbands, so career compromises may have led to permanent exits. However, women with bachelor's or master's degrees who found employment outside of academia had more difficulty later in their families' development, forced to balance the demands of children with inflexible work situations.

A third of the interviewed women pointed to an unsatisfactory mentoring situation as a main reason for their exit from science. Seventy-three percent explained how either positive mentors helped advance their careers or hostile, indifferent mentors impeded them. Mentors were also important in determining success in graduate school. Only 13.5 percent of the women had guidance as an undergraduate, and 20.5 percent of women in graduate programs were assisted by senior scientists. Mentoring relationships were present in 53 percent of employment situations.

Many women also became disenchanted with science as a career over the course of time. Some were unhappy with the narrowness of the field, or the competition among scientists coping for grant money. Others rejected the personal isolation and lack of personal contact associated with their jobs.

Preston proposed several solutions to these factors, such as an alternative to the high-mobility work path of Ph.D.s, family-friendly work environments, more workplace mentoring programs, and human resources practices that emphasize connections among employees.

Preston's presentation was based on her manuscript Leaving Science: Occupational Exit of Scientifically Trained Men and Women Between 1970 and 1990.