For more than a century, scientists have debated whether intelligence is mostly a product of nature or nurture. Identical ...

There’s a common assumption that intelligence is largely determined by genetics. After all, previously published studies ...

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 ...

Their children are genetic siblings, known as quaternary twins. After identical twin sisters from Delaware married identical twin brothers from Tennessee, the children they are raising together share ...

Sarah and Aimee Charlwood are identical twins. They didn't spend a day apart until they were 16. They share the same ...

After believing that her daughters were fraternal twins for so long, a mom was stunned when a genetic test revealed otherwise. Not long after Tamara Vanderent, 30, discovered that she was expecting ...

A century-old Mt. Everest mystery is being put to the test as identical twins climb the Himalayas – one in 1920s gear and the other in modern clothing.