I think there are two threads of thought I'd like to contribute to. I think the concept of Platonic forms is really appropriate and relevant here, that is I think precisely what people are talking and thinking about whether they have encountered or explored that concept before. Plato was hugely influential to western thinking.
Here's a thought experiment, you're in front of the class of primary school kids
The special 'woman' essence / mind / soul exists you tell them let's think about what it is, you're a trained teacher so you ask them questions, they give you answers, you write the answers on the board. What is it that you could possibly end up with that isn't a sex stereotype?
Wouldn't it be better to run the lesson as...
divide the whiteboard into 3
just for girls - both girls and boys - just for boys
Start with Hobbies:
What hobbies are only for girls? [take answers, see if anyone disagrees, write it on the board in the appropriate place]
What hobbies are only for boys [take answers, see if anyone disagrees, write it on the board in the appropriate place]
What hobbies can both boys and girls do [take answers, see if anyone disagrees, write it on the board in the appropriate place]
I would imagine in this country that children would actually be quite uncomfortable answering the first 2 questions, I'd be surprised if you had more than 1 or 2 answers in either the boys or girls column - by the time you got to question 3 they'd be giving you hobbies faster than you could write them. IF you had anything in the boys or girls column go back and reframe the question as do we actually think boys can't do this? Why not, what stops them? Repeat for the girls column. rub out and move if / when the class wants you to.
Repeat for tv programs, music they listen to, sports they do (or want to try), jobs they do (or would want to do), there may never have been a woman who was president of the united states but there have demonstrably been a number of women and girls who wanted to be.- food & drinks ( show the yorkie bar "it's not for girls advert" - I would expect the kids to laugh).
Talk about personality words:
careless / careful
strong / weak
kind / mean
decisive/ indecisive
determined
ambitious
confident
as you're writing them ask if people think this is a good thing to be...
boss
bossy - is bossy a good thing to be?
see how the kids take it - talk about the way sexism sometimes 'punishes' girls and women with bad words for behaviours that would get a good word for a boy or man. What might be called confident / decisive / determined in a boy or man being called bossy in a girl - is that fair?
Talk about who you're allowed to fall in love with... give examples of famous 'out' people if necessary as a prompt but it's likely someone in the class will give you the answer that women are allowed to fall in love with women, and vice versa.
Show some photos of famous people who did not present in conventional or expected ways. Explain hair make up and dress can be thought of in the same way.
Some men want to wear make up and some women want to wear make up and (although there's a rule against wearing it to school) that's ok. It isn't compulsory for anyone and although it's more commonly done by women than men - wearing make up, nail varnish, of elaborate hairstyles doesn't make you any less of a man, or any more of a woman. Say that sometimes men dressing in colourful clothes, using make up having elaborate hairstyles might also be gay and be attracted to men, or they might be bisexual and be attracted to men and women.
You spend you childhood figuring out what kind of a grown up you want to be, what hobbies are you, what sports you enjoy doing or watching, what clothes suit you and make you feel happy and confident, figure it out and be the best happiest version of yourself and no need to mind or worry about the fact that there are lots of different ways to be a man, and lots of different ways to be a woman.
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It seems to me that that is a much better and more helpful lesson for children to hear