WASHINGTON – Gender bias – not any biological difference between the sexes – stifles careers of female scientists at U.S. universities, says a new report.

The study is the latest since Harvard University’s president ignited controversy last year by suggesting that innate gender differences may partly explain why fewer women than men reach top science jobs. The comment eventually cost him his job.

Four times more men than women who hold doctorates in science and engineering have full-time faculty positions, the National Academy of Sciences reported Monday.

Female scientists typically are paid less, promoted more slowly and receive less funding than male colleagues, discrepancies not explained by productivity, the scientific significance of their work or other performance measures, the report found.

“It is not lack of talent but unintentional biases and outmoded institutional structures that are hindering the access and advancement of women,” it said.

University of Miami President Donna Shalala, a former Health and Human Services secretary, headed the committee that wrote the report. It calls on:

•The government to enforce existing anti-discrimination laws.

•University leaders to publicize the gender makeup of student enrollments and faculty ranks each year, and counteract bias in hiring and promotion.

•Funders of scientific research to allow grant money for dependent care, so scientists can attend work-related conferences or perform after-hours research.