Why do you think poorer countries tend to be in the south and richer countries tend to be in the north and list some possible reasons?

There does seem to be a pattern showing that the richer countries are in the north, and the poorer countries in the south. While there are some clear exceptions (Australia) it does seem that North America, Europe and Japan are far economically superior to South America, Africa and the Pacific. Perhaps it is because the people of the European region were among the first to develop superior technology and general civilisation. They also introduced these traits to other countries, particularly northern (U.S. and such). This is the only possible reason I can think of. If there are any additions to this, they would be greatly appreciated.