Feminist contributions to systemic approaches to human behaviour have led to gender being defined in interactional terms. Gender is seen not as a fixed quality or trait but as one socially constructed between men and woman. This idea is discussed in relation to the gender debate in family therapy, attachment theory and feminist contributions to psychoanalytic thinking. Gender relationships are created as part of a person's internal working models of self and other. The ways that gender patterns are carried forward are examined, especially with respect to the contradictions between a person's gendered internal working models and their experience. These ideas will be examined through case examples.