Since 1949, Chinese government promoted the use of birth control and family planning. In the 70's their population was close to the one-billion mark, the government was worried, in 1978 they encouraged families to have no more than two children, on child being preferible. The campaing's slogan was "Late, Long, and Few". The next year, a policy was introduced, this policy required couples from the ethnic Han majority to limit themselves to one child. This was known as the "One child policy".
A range of cultural, religious, and racial ideologies were used to justify imperialism, including Social Darwinism, nationalism, the concept of the civilizing mission, and the desire to religiously convert indigenous populations.