Why do some people live to 100 while their sibling dies decades earlier? Is it luck, lifestyle, or something written into their DNA? Relative to many other species, humans are particularly long-lived, ...

When we think of identical twins, we often imagine mirror images — same face, same smile and perhaps even the same talents. But what surprises many is that these genetic carbon copies can have ...

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 ...