My DS is 4, started reception in September. Up till then he has never had any negativity from us or from extended family (though had to virtually gag FIL occasionally) about girls or women. If he liked something, (eg toys or when he fell in love with a pink kids handbag) we have never expressed any judgement and he's never seen things as 'just for girls' or 'just for boys'.
Now he's recently started to speak in a derogatory way about anything he perceives as 'for girls'. Such as using a pink cup. Ffs! Or saying that boys are so much better than girls at X. We've been pulling him up on it every time and DH has been making a point of talking about it with him when he does.
There is a definite split socially at school and the girls and boys only seem to play with kids of the same gender but I wasn't expecting to hear this shit come out of his mouth so young!
It has opened DH's eyes to the conditioning that takes place socially. He has discovered feminism with me as I have talked a lot with him as I have had my own eyes opened over the last few years, so I'm glad DS at least has a positive feminist male role model in his life. Still depressed the shit out of me though, I have to admit.
He's only 4 ffs! No wonder we live in a patriarchal society.