They only learn to be frightened of those differences when an adult influences them to behave that way, and maybe censors that natural curiosity, or you know, reins in the question-asking in the hopes of them being polite little kids.
Elas só aprendem a ter medo dessas diferenças quando um adulto as influencia a ser assim, e talvez censure essa curiosidade e controle as perguntas esperando que elas sejam criancinhas comportadas.