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

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

The 37-year-old sisters both gave birth on Aug. 26. Two twin sisters say it's "surreal" that they gave birth to their babies on the same day and in the same hospital. Identical twins Rachel ...

The mom was 20 weeks pregnant when she discovered that her twins, Graylen and Chaysen, had twin-to-twin transfusion syndrome.

Identical twins who were raised apart may have IQ differences similar to those of total strangers, according to new research.