The Children of Twins Design: What have we learned and where should we head next?

The transmission of traits within families is well-recognised, but the underlying processes are not fully understood. Twin studies of both child and adult populations demonstrate the presence of both genetic and environmental... [ view full abstract ]

The transmission of traits within families is well-recognised, but the underlying processes are not fully understood. Twin studies of both child and adult populations demonstrate the presence of both genetic and environmental influences on almost every aspect of human behaviour and psychological development. Furthermore, multiple aspects of parenting, parental mental health, and the parent-child relationship are associated with offspring outcomes. The Children-of-Twins design is a valuable method in evaluating the relative contribution of genetic transmission versus direct transmission of traits from parents to their children. In this talk I will give an overview of what this method has shown to date, with a particular focus on transmission of depression and anxiety across generations, and associations between parenting and anxiety/depression in offspring. I will then describe the limitations of the design, and make some suggestions as to how we might overcome these. I will end by describing a new Children of Twins Study which we are just beginning.