Study paper from 2006 in the field of Education - Educational Psychology, grade: 1.5, University of Lüneburg, 17 sources in the bibliography, language: German. Abstract: The sibling relationship is the longest-lasting relationship of all. Whether a person grows up with siblings or as an only child, and what position they occupy in the sibling hierarchy, is significant for their entire life. According to a survey by the Federal Statistical Office from the year 2000, one in four children is an only child. Every second child grows up with at least one sibling. This also includes half-siblings, adoptive siblings, or other combinations that arise in what is known as a blended family. The situation the child faces within the family forms the basis for their later life and influences their thinking about themselves and the world.