The population of Japan has been decreasing for several years now because women have been choosing careers over family and are less likely to get married and have children.

In Nigeria, on the contrary, since 1960 the population has grown 4 times. Here, people want to have big families. And in the northern part of the country, men often live with several wives and every wife wants to have as many children as possible in order to be the top woman of the family.