6 panel comic, all panels show a student at a desk and a teacher pointing at a board
Top pair:
1 basic math(s): on the board is the number minus one within a root symbol, both within a red circle with a line through it, implying there is no root to minus one.
2 advanced math(s): on the board is the root of minus one equals i
Middle pair:
3 basic physics: on the board it says "3 states of matter"
4 advanced physics: on the board the it says "3 states of matter" but the 3 is crossed out and replaced with a 4 which is also crossed out and replaced with a 7+
Bottom pair:
5 basic biology: on the board it says: " 2 sexes" above a simple table that shows F and M
6 advanced biology: on the board it say: "sex ≠ gender" above a graph of bimodal distribution where one peak is marked M and the other F. At this point the student reacts: "Nooooooo!!!
My 2 genderinos"
Gender being a separate thing from sex is entirely made up. It has no basis in science.
[citation needed]
Most of psychology is entirely made up.
But anyway, the fact that trans people exist would seem to contradict your premise.