The question of whether it is better to educate boys and girls separately has been debated for centuries. Advocates of single-sex schools argue boys and girls learn differently, while those who support coeducation say it reflects the real world.

In recent decades, the real world argument appeared to be winning as more schools opted to go coed. But something happened last year in Sydney. After the elite boys school Newington College announced its decision to start accepting girls, the response was extreme.