My understanding (and it could be incorrect) is that this is more of a definitional/philosophical thing.
Though you are more than welcome to read directly from the source Judith Butler who (to my understanding) first started this theory on gender:
https://www.amherst.edu/system/files/media/1650/butler_performative_acts.pdf
Stealing the answer because I’m nowhere near as articulate on this matter:
The basic (and simplified) idea is that gender–what we think of as masculine and/or feminine–is performed in the ways we act, speak, dress, move, etc. and doesn’t really exist outside of that performance. We learn how to perform this way from dominant culture and conventions–what someone might (incorrectly) call “normal male” or “normal female” behavior. But these “normal” qualities (and genders themselves) don’t actually exist–rather, we are all repeatedly mimicking them and are rewarded for doing so (or punished for not doing so). We merely impersonate the qualities we’ve been taught match the gender we’ve been told we possess (like females being demure or males being aggressive) until those impersonations (and gender itself) become belief and seen as something natural and assumed.
https://www.reddit.com/r/explainlikeimfive/comments/4dddcq/eli5butlers_gender_performativity/
I’ve played enough KSP to know that’s a good location to crash.
We could instead be out of billionaires in two months.