When and why it was implemented? There's a post about China not having enough women so is it true they drown female babies? Sorry if this is an ignorant question. Thank you for your responses.
I'm genuinely curious. Are you still awaiting a response, or after several hours have you just googled it?
This is somewhat of a geographical question as it focuses more on demographics and is actually taught in geography itself. Though the main things about it are as follows:
It began in 1979 and still lasts today although the policy was relaxed in 2013.
It was implemented because China was experiencing very bad over population, in essence, so the Chinese government implemented the policy to attempt to decrease the number of births a couple could have.
In order to fully implement this they had laws against having more than one child (unless, I think, in the circumstance that the first born was female). Such punishments would be generally fines which would be rather expensive for a couple to pay.
In terms of twins etc. the couple would generally be allowed to keep them without a fine (I believe) due to it not actually being a planned thing.
The reason you hear so much about female babies being killed is because generally Chinese couples wanted male children to continue their family name and inheritance. Whether or not it is completely true that they did kill female babies I have no plausible idea. However, if the couple knew they were going to have a female baby they would most likely have aborted it and tried again alongside the fact that there were reports of female children being abandoned, thus explaining China's current lack of women.
Hope I helped.