TIL in 1970, average Chinese women gave birth to 6.1 children. That's just before my sister was born!
Then China's State Council under Zhou Enlai produced slogan in 1970: 一个不少，两个正好，三个多了 (1 not too few, 2 perfect, 3 too much). Thus began Chinese family planning policy that led to dramatic reduction of births in China.

Chinese birthrate was also higher than India in 1970 while China had much bigger population (818 million) than India (557 million)

At the time China rolled out family planning policy, China had 818 million population and higher fertility rate 6.08 vs India's 557 million w fertility rate of 5.06.
Wonder how things might've turned out if China had allowed for natural decline of birthrate like India did

Before China implemented One Child Policy nationwide in 1980, birthrate already crashed to 2.7 children per women due to 1970s gov policy of later marriage age and encourage to have only 2 children.
But because 2.7 children was still way above replacement rate of 2.1, more drastic One Child Policy was put in place in 1980