Sandra Bem, a feminist psychologist whose pioneering work in gender roles paved the way for equal employment opportunities for women across the country, died Tuesday at her home in Ithaca, N.Y.

A Pittsburgh native who did her early research at Carnegie Mellon University, she was 69 and the past director of the Women's Studies Program at Cornell, where she was a professor.

The cause of death was suicide.

When she was diagnosed four years ago with Alzheimer's, she said she would end her life while she still could when the disease became too debilitating to continue.

After years of expensive medical treatments, she stopped all care six months ago and decided it was time to die.

She bought a copy of "The Peaceful Pill Handbook" and chose to take her life with pentobarbital.

The family held a service for her two days before her death.

"Instead of a funeral service, the family met with her last Sunday, a group gathering where we all shared our memories of her and our thoughts and feelings," said her husband, Daryl Bem, 75, also a nationally recognized psychologist. "Everyone was aware of the fact that Tuesday was the deadline."

After spending her last day with Daryl, during which the couple went for a long walk, watched a movie and had dinner, Sandra took the drug at about 7 p.m. Tuesday and died in her sleep.

The Bems, who both started their careers at CMU, did numerous studies on gender stereotyping and were active in the feminist movement throughout the 1960s, '70s and '80s.

"Their work was very important in the early days of feminism," said Eleanor Smeal, president of the Feminist Majority Foundation in Washington and a former Pittsburgh resident who served as president of the National Organization for Women. "We didn't have a lot of studies back then. At that time, they were pioneers. They argued that sex stereotyping was started at a very young age and created an unequal playing field for girls and women. Their research was widely used and very influential."

Ms. Bem believed that sex roles were largely determined by cultural norms that created a male-dominated society.

She spent her life trying to eliminate those stereotypes.

While still a young researcher, Ms. Bem was an expert witness in two national sex discrimination cases, one of which started in Pittsburgh.

In 1969, NOW filed a complaint against The Pittsburgh Press for its practice of segregating its classified job listings under "Male Help Wanted" and "Female Help Wanted" columns.

The male column included many more opportunities for jobs and advancement while the female column contained only a narrow range of typical women's jobs of the time.

To bolster NOW's case, the Bems did a simple study in which they showed that female CMU students were more likely to apply for male-oriented jobs if the listings were alphabetical rather than categorized under sex.

The case ultimately ended up before the U.S. Supreme Court, which in 1973 ruled 5-4 against the Press.

"The miracle of that decision is that within a year almost all newspapers across the country changed their classified ads," Ms. Smeal said.

Ms. Bem authored several books. "The Lenses of Gender: Transforming the Debate on Sexual Inequality," published in 1993, was selected the Best Book in Psychology for that year by the Association of American Publishers.

In 1998, she published "An Unconventional Family," a memoir of her 30-year marriage to Daryl, their roles in the feminist movement and their attempts to raise their two children, Jeremy and Emily, to be free of gender constraints.

Emily now works in musical theater in Austin, Texas, and Jeremy, a math whiz, became a multimillionaire at Google and retired to Montana.

Ms. Bem was born in Squirrel Hill in 1944, the daughter of a postal worker and a secretary, and spent her early years in public housing.

She attended Hillel Academy and Allderdice High School. Her mother complained about housework and told her and her sister that being a housewife was "not very desirable," an attitude that spurred her to achieve.

She earned her bachelor's degree in psychology from Carnegie Institute of Technology, now CMU, in 1965, and during her senior year there met Daryl, an assistant professor. They married a few months later.

At his suggestion, she decided to pursue her doctorate in developmental psychology at the University of Michigan and received the degree in 1967. She then joined Daryl on the psychology faculty at CMU.

The two were devoted to the feminist cause, which had strong roots in Pittsburgh, giving talks on gender roles at churches and other institutions around the city.

Two years later, they left for Stanford, where Ms. Bem started her research on gender and androgyny.

She was honored many times for her work. She received the American Psychological Association's Distinguished Scientific Award for early contributions to psychology in 1976 and the American Association of University Women's Young Scholar Award in 1980.

She twice won the Association for Women in Psychology's Distinguished Publication Award, first in 1977 and then in 1994 for "The Lenses of Gender."

After she left Stanford in 1978 because she did not receive tenure, she and Daryl accepted positions at Cornell.

She had always had an interest in clinical psychology, and in the late 1990s took a sabbatical from Cornell to return to school at Rutgers. She received her license to practice psychotherapy in New York in 2000 and opened a part-time practice in Ithaca.

She retired from Cornell in 2010.

In addition to her husband and children, she is survived by her sister, Beverly Lipsitz of Portland.

Ms. Bem was cremated Thursday.

First Published: May 23, 2014, 2:51 a.m.