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.

A new analysis of studies spanning the last century finds that differences in schooling appear to explain a large portion of ...

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

When identical twins Chaysen and Graylen were in their mother Jessica Proudfoot’s womb, doctors discovered the beginning of ...