ABSTRACT
Parents with more than one child are often surprised that their children are "like chalk and cheese" in terms of their behaviour, interests and abilities. Despite anecdotal evidence of large differences between siblings, psychologists have traditionally focused on differences between rather than within families to explain children's developmental outcomes. As a result, shared genes and shared environmental influences are often assumed to lead to similarities across children within the same family. This chapter discusses three different approaches to explore the interdependence of family relationships. First, it considers the convergence between different family members' perspectives of the sibling relationship. Next, the chapter discusses the lens of spillover and compensatory processes to consider the interplay between the quality of sibling relationships and the quality of parent–child relationships. The chapter then examine links between parental differential treatment and sibling relationship quality to consider how two parent–child subsystems can interact with the sibling subsystem.
