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

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

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

Identical, or monozygotic, twins develop from the same fertilized egg that splits into two. These twins are the same sex and share the same genes. Sometimes called paternal twins, identical twins ...

A comedy of errors ensues when two sets of identical twin brothers, separated at birth, find themselves in the same city. Their lives and relationships become a hilarious, chaotic tangle of mistaken ...

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 ...