Few individuals can raise $500,000 by accident. But that's exactly what Anne Petersen, PhD, did during a 1991 donor reception at Pennsylvania State University, where she served as a department head for five years before her 1987 appointment as dean of the school's College of Health and Human Development.

By mistake, Petersen announced that a well-known donor had given $1 million to the school, when in reality he'd only pledged half that amount.

"He stood up and said, 'I guess I've gotta write another check,' and he did," says Petersen, now deputy director of the Center for Advanced Study in the Behavioral Sciences (CASBS), an independent facility on the grounds of Stanford University that provides fellowships to top scholars in an effort to spark discoveries.

Yet it's no accident that the "Encyclopedia of Psychology" (Washington, D.C.: APA; New York: Oxford University Press, 2000) features Petersen as one of the 200 most influential psychologists and neuroscientists. As the first woman in nearly all of her positions-from senior vice president for programs at the W.K. Kellogg Foundation to deputy director and chief operating officer at the National Science Foundation (NSF), to vice president for research at the University of Minnesota-Petersen makes it her mission to advance and empower women in science-and encourages others to do the same.

Her first opportunity to affect change came at Penn State, when she noticed that a selection committee for one of the highest university honors-Faculty Scholar Medals-did not include a single woman. She wrote to the university's president and convinced him of the importance of recognizing women. Today, many women serve on the selection committee and have been honored with the awards.

"That helped me see [my] leadership roles as not just performing duties, but rather opportunities to make a difference," Petersen says.

Not only does she make sure women get their due, she also mentors them along the way. Shortly after finishing her PhD in measurement, evaluation and statistical analysis at the University of Chicago in 1973, she formed a small Midwest organization called Research on Women and Education, which facilitates communication about women in education among researchers and practitioners. Still going strong, the group is now a special interest group within the American Educational Research Association.

In 1995, Petersen also helped coordinate NSF's first Women and Science conference, to examine the role of women in science and engineering and encourage continued success in these fields.

Now at CASBS, Petersen says she wants to boost the diversity at the center, where women and minorities made up less than 50 percent of the 2006-2007 class of fellows. As she's done throughout her career, Petersen is devoted to improving that representation through increased diversity among the fellows, to help CASBS play a stronger role in advancing fields and serving society.

"I'm hoping that in five years, we will have cohorts of residential fellows who are much more diverse in all respects-gender, race and ethnicity,age, institution and international origins," she concludes.

--A. Cynkar