When I arrived in the university town of Nanjing on my first visit to China in 2007, I spent days on end watching and talking to students, marvelling above all at the confidence, competence and poise of the girls. I was working on a book about Pearl Buck, who grew up in the Chinese countryside before teaching on the Nanjing campus in the 1920s, so I knew a lot about the world of these girls’ grandmothers: a slow-moving world where traffic went by river steamer or canal boat, and the only wheeled vehicle most people ever saw was a wheelbarrow. Girls were shut up at home on reaching puberty with no further access to the outside world, and no voice in their own or their family’s affairs.