The Impact of Siblings on Development: Introduction to the Section

This section calls attention to the undertheorized and undervalued impact of sibling relationships on development and how sibling relationships are influenced by, but distinct from, parent–child relationships. Although sibling rivalry has long been recognized, the rich domain of early patterning for lateral experiences – reciprocity, turn-taking, recognition, and validation – has been overlooked. The papers that follow draw on a variety of perspectives and methodologies – case presentations, longitudinal studies, historical perspectives, neurocognitive research, attachment theory – to explore the many factors that contribute to the fate of sibling rivalry, such as parental favoritism, birth order, parental sibling relationships, parental fantasies about their child, changes during developmental phases, the effect of adoption, and whether or not siblings are concordant (see parents in similar ways in terms of attachment). In identifying cognitive organizations crucial to healthy or unhealthy development, the papers demonstrate how the intensity of early sibling experiences can lead to resistances that must be addressed for healthy growth.