Anna Vannucci has a twin. Her younger sisters are also twins. Despite the shared genes and the close proximity in age (all four siblings were born within 15 months of each other), Vannucci and her siblings all had deeply different personalities. At the age of 8, Vannucci sat her siblings down on a couch and asked them questions to try to get to the bottom of why they all seemed so different.
https://medicalxpress.com/news/2025-01-qa-ai-early-childhood-affect.html