@Lilith_Atheist It makes an excellent point about the religious mind. Because they consider their indoctrination to be reality, they fear everything else can be taught to young children too. Even innate characteristics that no amount of tuition could influence.
The scrotum's skin, rich in nerve endings, is highly sensitive to touch. Especially when scrotal hair is tickled or moved, it activates these nerves, awakening the beast within.