Over the past 4 decades, the rate of multiple births in the United States has increased; the body of empirical research examining twins' developmental experience has also grown, but has yet to be systematically reviewed in ways that might inform mental health care providers' work with members of twin pairs. The small existing literature suggests that while families with twin children may face distinctive challenges, such as increased stress, particularly during infancy and toddlerhood, most twins develop typically, and are largely indistinguishable from singletons by school age. However, given the relative dearth of literature, anecdotal areas of importance for twin development (e.g., parent-child interactions in older children and autonomy development) that are not supported by empirical literature are emphasized as directions for future research. This article provides a meta-analysis and systematic review of the literature examining twin development as compared with singleton development and then offers suggestions based on the available data for how to incorporate these findings into clinical practice.
Public Significance StatementThere are more twins in the United States than ever before, and many may seek treatment. This article offers a review of the literature on twin development and the ways in which it converges and diverges from that of singleton children. It then provides recommendations to guide clinicians in helping families with twins digest, evaluate, and make use of existing findings.