Hacker News Reader

> A better comparison would be separated twins (widely separated).

The two people in The Parent Trap are twins and were widely separated, yet they still looked identical, so much so that their parents could not even tell them apart.

There is a documentary I think on Netflix of twins who find each other randomly on the internet. I think the were Korean and we're adopted by two families. One in California and another in France.

It is common to compare traits in monozygotic vs dizygotic twins to help control for shared environments.