Assigned Gamer at Birth

Was thinking about AGAB (assigned gender at birth) and thus about sex and gender and I thought--what if it was assigned gamer at birth? Like, what if a doctor glanced at an infant's genitals fresh out of the womb and decided "yeah, this kid is a gamer". Wouldn't that be ridiculous? And yet its considered normal for people to expect that glance to dictate behavior and roles in almost every aspect of a person's life and to magically include x-ray vision and a genetics test as well.