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 ...

You can have three babies that are identical (if one egg splits into three embryos), three babies that are fraternal (if three separate eggs are fertilized), or two babies that are identical and one ...