Ignoring intersex people (born with variations in sex characteristics).
Erasing the experiences of transgender and non-binary people
Based on the principle that gender is strictly binary (male/female).      Â
The American Academy of Pediatrics emphasizes:
"Gender identity is a person's internal sense of their own gender, which may or may not correspond to the sex assigned at birth. It usually appears between the ages of 2 and 4."
Babies don't act like a specific gender. They simply behave like babies.