Individuals and Their Peers: A Structural Perspective Peer relationships are diverse in the sense that their degree of obligation, their intensity, their stability and even their number of participants vary. At the same time they have effects on the intraindividual and interindividual development of children and adolescents who tend to value them highly. Sociometric peer nominations provide one way of describing the complexity of peer relationships and of analyzing their various determinants. Peers are sources of information in the context of a defined system like a classroom in school. The consistency of this information (how many children like A and how many children like B), its reciprocity, and its stability are structural parameters that - in concert with other psychological constructs - may provide valuable cues and predictions about the optimal conditions for a positive peer socialization. The present article attempts to use these structural elements as the point of departure by navigating through the complexity, in order to delineate existing knowledge before the background of open questions and important question marks.