Sex, Culture and Modernity in China (London: Hurst; Honolulu: Hawaii University Press, 1995) showed how sexuality gradually became an object of investigation, surveillance and intervention for the sake of state power in the early twentieth century. Prostitution, masturbation, homosexuality and other forms of sexual activity not linked to procreation were all viewed with deep suspicion by the elite. The book also demonstrated how a dubious 'science of sexuality' justified gender inequality, as women were widely portrayed to be biologically inferior to men in terms of body and mind: their primary role was to produce healthy babies for a healthy nation.