Science

actually youre right. It was only when fuedalistic societies starting forming and and non-males were increasingly seen as. 'objects to prodice more soldiers , hiers, and more workers' and were increasingly put under the control of patriarchal men and even non-males who betrayed their own non-male allies did this binary idea become more convenient for the fuedalists to adopt. ANd so....

Thats what they went along with and most of us went along with it.

Back inthe neolithic era there probably wasnt even a rigid classification for gender. If you were born intersex or agenderd you woulsd probably just get treated like which of your genstalia mattered the most or based on what your mother or her mother's mother said about people who were intersex.