The nature of adult twin relationships: an attachment-theoretical perspective

Twin relationships have been hailed as one of the most unique and intimate kinds of relationships. Unfortunately, there is a paucity of empirical research that addresses the interpersonal nature of twin relationships. In this article, the authors argue that attachment theory may provide a useful framework for understanding the nature of twin relationships. The authors present data indicating that (a) twins are more likely than non-twin siblings to use their sibling as an attachment figure; (b) the developmental course of twin attachment differs from that of other attachments; and (c) certain factors, such as genetic relatedness, empathy, including the other in the self, and shared experiences, may impact the extent to which twins use one another as attachment figures.