Siblings: They love and they hate each other. This is especially true during puberty, when the question of one's own identity comes to the forefront. What role do sibling relationships play in identity development? And do twins have a particularly hard time developing their own independent identity? In this book, Meike Watzlawik explores the development of twins and siblings with a maximum age difference of two years. She discovered that it is not twins per se, but identical twins who occupy a special role among the five sibling groups studied, due to the possibility of mirroring each other. Opposite-sex siblings have the least in common, which also affects their relationship with one another. A book for family researchers, parents, and siblings.