Carol Gilligan is an American psychologist known for her research in gender issues, ethical decision making, and hierarchies. Gilligan did research with Lawrence Kohlberg and helped to develop his stages of moral development. She disagreed with his interpretation that only men had the ability to perform moral reasoning. Her 1982 book "In a Different Voice" challenged the psychological notions that excluded and demeaned women and generalized research results to women that came from studies conducted only with men.
Kohlberg's results were challenged as only males were used in the research for the stages of moral development and these results were generalized to women.
Gilligan's research with females shows that women are in fact capable of moral reasoning but that they use a different method than men which wasn't measured in Kohlberg's research. Gilligan is a founder of difference feminism which is a perspective that acknowledges that there are different methods and qualities between men and women but that no value or judgment should be placed on these differences (one decision making method being better than another for example).