Twins which were raised separately are often used for such studies: https://www.google.com/amp/s/www.cbsnews.com/amp/news/just-alike-twins-separated-at-birth/ h

Twins which were raised separately are often used for such studies: https://www.google.com/amp/s/www.cbsnews.com/amp/news/just-alike-twins-separated-at-birth/ https://www.google.com/amp/s/www.cbsnews.com/amp/news/just-a...