Just because you grew up in the same home doesn't mean you had the same experience. Experts break down how and why this ...

and gender nonbinary people, it does not. It's for this reason that identical twins can ultimately have different genders. Can Identical Twins Ever Be Different Sexes? In extremely rare cases ...

A conjoined twin has revealed that he hid his true gender identity, keeping it a secret from his sister for decades, a report ...

Can fraternal twins have different fathers ... The Science of Fraternal Twins Mixed-gender twins are the most common type of fraternals, some 50 percent are boy-girl. To understand this ...

Born in 1961, conjoined twins George and Lori Schappell shared a skull and 30% of their brains. Assigned female at birth, ...

Identical twins do not share identical fingerprints.Fingerprint patterns are developed early during pregnancy, and the environment of the womb has a lot to do with how the prints are shaped. The ...

When they compared identical twins raised in different families ... Ten years ago, at 32, Juan began treatments to change gender. "I'm more comfortable in my body than ever before," he says.

This text and the language in the corresponding map was updated in consultation with a world gender expert* in October ... so you may need to log in under a different or personal email address ...

Elon Musk is the father of 14 children whom he welcomed with four women. Here's everything to know about Elon Musk's kids.

A new Pew Research Center survey finds that 1.6% of U.S. adults are transgender or nonbinary – that is, their gender is different from the sex they were assigned at birth.