In small towns, mostly everyone thinks alike. They mostly all have the same opinion, and there is no difference in what people think. In big cities, not everyone has the same opinion. People are able to debate about their opinions, because not everyone thinks the same. It also allows a child to be able to learn that not everyone will think the same way as them, therefore helping the child in the long run.
Also, in big cities, there are more education options. There are typically more schools for the child to choose from. Most schools specialize in different things,