Jessica Dunagan and Christina Manning shared their relationship trouble on TLC's "Extreme Sisters" when they clashed over who would attend a home birth.

A new video out of London’s Center for Fetal Care shows twins fighting. Not that interesting? Well, it gets better because these twins haven’t even been born yet: an MRI scan shows the beginnings of ...

From Romulus and Remus—the myth of the twin brothers who founded the city of Rome—to the synchronized speech of Australia's "Twinnies" Paula and Brigette Powers, identical siblings have long inspired ...