Biological Processes Are Never Universal

The process of sex differentiation ensures that human fetuses are born with distinct external & internal genitalia (which is used to assign their sex at birth).

However, in a small town in the Dominican Republic, a community known as the "Guevedoces" (translating to "penis at twelve") undergo a different process of sex differentiation.

Many of them are brought up girls due to the absence a penis & testes & the presence of a vagina.

When puberty approaches, some of their male sexual organs grow, and their biological sex is reassigned as male according to their genitalia.