Based on the largest study ever of sister relationships, "My Sister, My Self: The Surprising Ways that Being an Older, Middle, Younger or Twin Shaped Your Life" explores the myriad ways that a woman's place in the sister hierarchy makes an indelible imprint on her identity. It affects her in everything she does although she probably isn't aware of it - from her choice of occupation, her circle of friends, her love life - even how she feels about her own body! The book also shines a light on three special sister relationships - those that are conflicted, caretaking or super-close.