I hardly believed they were twins! Several years ago, one of my developmental psychology students told me that she had a fraternal twin sister who looked nothing like her, and it turned out that she ...

Twin estrangement starts with unresolved anger between twins in childhood. Perhaps one twin is favored over the other twin for parental personal reasons. Another explanation is that one twin is in ...

Mono-mono twins are an incredibly rare type of identical twins who share both a placenta and an amniotic sac. While this makes for a high-risk pregnancy, advances in monitoring and treatment have ...