Female genital mutilation in Africa persists despite modernization, pu
blic education, and legal prohibition. Female footbinding in China las
ted for 1,000 years but ended in a single generation. I show that each
practice is a self-enforcing convention, in Schelling's (1960) sense,
maintained by interdependent expectations on the marriage market. Eac
h practice originated under conditions of extreme resource polygyny as
a means of enforcing the imperial male's exclusive sexual access to h
is female consorts. Extreme polygyny also caused a competitive upward
flow of women and a downward flow of conjugal practices, accounting fo
r diffusion of the practices. A Schelling coordination diagram explain
s how the three methods of the Chinese campaign to abolish footbinding
succeeded in bringing it to a quick end. The pivotal innovation was t
o form associations of parents who pledged nor to footbind their daugh
ters nor let their sons marry footbound women. The ''convention'' hypo
thesis predicts that promotion of such pledge associations would help
bring female genital mutilation to an end.