“Bare branches,” the name given to unmarried men in China, have historically posed a great threat to social stability in that country. Based on historical records and literature, the findings in this study reveal that female infanticide, coupled with the practice of polygyny, meant that during the Ming and Qing dynasties and the Republican Era, up to twenty percent of males remained single. As a result, underclass bare branches turned to less socially accepted marriage practices. And if they were still unable to find a suitable marriage partner, they would turn to prostitutes, adultery with married women, or might even resort to sexual assault. Humiliated by their social status, bare branches tended to drift away from their hometowns and form brotherhoods, secret societies, bandit gangs and even military groups, posing a real threat to social stability. In extreme cases, they engaged in armed conflict, taking over government offices, clashing with government forces, destroying social infrastructure, and helping to topple dynastic regimes. Such extreme violence and disorder led to the reduction of local populations by the thousands or even millions, creating a subsequent negative effect on social development.