Relationships between women are often freighted with a rocky mix of emotions leading to anguish and confusion in the playground, in the home and in the boardroom. A woman's experience negotiating her feelings towards a sister shapes her psychology as forcefully as do her relationships with her parents. By exploring sisterhood, Terri Apter reveals its key role in understanding all relationships among women. In a series of compelling interviews, Apter considers the many aspects of the sister relationship. The need to fight to differentiate oneself from a sister, as well as the protectiveness one feels for that same person, is explained by reference to extensive psychological and biological evidence. Not only will sisters be enlightened by this original book: it sheds light on all relationships between women.