When Ms. magazine featured a Harvard professor on its cover last December, it sold more copies than a month earlier, when the feminist periodical spotlighted rock star Bette Midler.

The academic with the big selling power was Carol Gilligan, associate professor of Education at the Graduate School of Education, who Ms. named "Woman of the Year."

A few months after the Ms. story. The New York Times also focused public attention on Gilligan, heralding her as a "vanguard" of a movement of new psychological research on women.

Gilligan's recent national exposure is the result of her pioneering research on the differences between male and female moral reasoning and the conclusions she has drawn about human development.

Her work, Ms. editor Ruth Sullivan says, "will have a profound effect on the way people think about women for years to come."

Gilligan's research reveals that while men tend to make decisions based on concern for rules, justice and individual rights, women's moral decisions more often are relative to the situation and place a greater emphasis on an ethic of care and on the preservation of relationships.

Traditional theories of development like that of Lawrence Kohlberg, professor of Education and Social Psychology, show a child progressing from a concern with the context of the situation and maintaining relationships to higher stages where decisions grow out of a principled devotion to justice and individual rights.

Gilligan, who is 46, argues that these stages don't fairly represent the ethic of care and responsibility that she has found in her interviews with girls and women. "Women just don't fit the schemes." Gilligan says, adding, "rather than finding problems in female development. I find problems in the schemes."

Gilligan's work marks the first time anyone has studied female moral development. "Before Gilligan's work there wasn't enough material to write a chapter on girls and moral develpment," says Edith Phelps, the director of a new center for the study of gender, education and human development at the Ed School.

"Females have always been discrepant data. I'm using the discrepent data to explicate female development and new theory," Gilligan says, pointing to the male-oriented research of Kohlberg, Erik Erickson and Jean Piaget.

In her recent book, In a Different Voice, Gilligan cites an interview with two 11-year-olds, a boy and a girl, explaining the differences in their moral reasoning processes and the implications of using the traditional stage theory of development to evaluate the children.

When confronted with a moral problem--whether or not a poor man should steal a drug for his dying wife that the druggist would not give him--the boy and girl responded differently in ways that, according to Gilligan, reveal the two distinct moral voices.

Jake, the 11-year-old boy, had little trouble deciding that the husband should steal the drug. His reasoning that a "human life is worth more than money" would, Gilligan says, place him at a high stage of development on a traditional scale, one that shows a principled concern for fairness and deductive logical thinking.

Eleven-year-old Amy's reasoning follows a different path. She is reluctant to let the man steal the drug because she thinks he might be able to solve his dilemma by negotiating with the druggist. She has trouble understanding the druggist's refusal to provide the drug free of charge, his lack of care and concern. Gilligan argues that this difference of approach reveals that women tend to focus on care and on the relationships in a particular situation rather than on principles of justice or fairness.

On Kohlberg's scale, Amy is placed on a lower level than Jake because she "seemed to reveal a feeling of powerlessness in the world, an inability to think systematically about the concepts of morality or law."