[Tsuwabuki]

Essentialisation means thinking of all people in a category have some inherent similarity.

The example used when I learned about it was the view that all members of the African Diaspora have an inherent similarity because of colonialism and slavery.

I reject essentialisationist views. The idea that all women are inherently similar because of their biology is just such a view. It's more than just stereotyping, because it often relies on an idea of something that is far more permanent and less malleable. That it is a limitation that has natural reasoning behind it, and it cannot be overcome.

Your view that boys and girls cannot play rugby together is essentialisationalist, and I reject it out of hand, the same way I reject notions that it is impossible for some woman at some point to meet the standards for being a US Navy Seal, as an example. Rare, perhaps. Yet not impossible.