Karen Horney (1885 - 1952) is known for developing Feminine Psychology. Her work has influenced how psychology views gender differences. Horney disagreed with Sigmund Freud's view of women, and countered his idea of penis envy, which refers to a girl's reaction upon realizing that she is different from boys, with her own idea of womb envy.
According to Horney, both men and women have a need to feel productive. Women are able to satisfy this need in two ways: by being a productive member of society through work, and interiorly by bearing children and giving birth. On the other hand, men can only accomplish this need through external ways, and so they compensate for their inability to bear children by focusing on achievements in their career. Horney's work on feminine psychology was useful in promoting equality between the genders.
Horney also developed a theory of neuroses, which she defined as a counterproductive manner of dealing with relationships. She identified three categories of neurotic needs. The need for compliance refers to a tendency to move towards people, manifested by a need to seek approval from others. The need for aggression refers to a tendency to go against people by being selfish, bossy, or demanding. The need for detachment, or a tendency to move away from people by insisting on one's self-sufficiency and insistence on perfection.