Does Family Complexity Matter for Children's Well-being and development?

How the characteristics of their families affect children’s well-being and development has long being of interest to researchers. Consideration of the demographic characteristics of the family has in the past predominately focused on the partnership of the parents, this thesis looks beyond this to create a broader measure of structural family complexity. Family complexity consists of both the parental partnership history of the parents in the family and the degree of relatedness amongst siblings in the family. This thesis looks at parental partnership history and the child’s sibling group structure individually before combining both these aspects to examine the role of family complexity for children’s well being and development outcomes. In doing so, this thesis aims to offer an insight into what aspects of children’s family structure matters for children’s well-being and development and therefore how best to promote their outcomes. The thesis uses data from the Millennium Cohort Study, using problematic externalising and internalising behaviour and age adjusted poor reading ability as outcomes at the age of seven. Three alternative ways of measuring parental partnership, trajectory, transitions, and status are examined individually and then compared in order to outline the implications of these different specifications. The association between children’s complex sibling groups and their outcomes is investigated, with an association between complex sibling groups, i.e. those with half siblings, and poorer outcomes for children. Finally, family complexity is examined using logistic regression, both with and without interaction effects, and propensity score matching. The results of this analysis suggest that the composition of the child’s sibling group is more informative of their likelihood to have poor outcomes than their parent’s partnership. Poorer outcomes are associated with younger half siblings and stepparents but not with stepparents only for externalising behaviour. Children who have older half siblings, regardless of their biological parent’s partnership status, are at increased risk of poorer reading outcomes for age.