Climate is closely related to economic development  In Europe, countries with colder climates in the north are generally more developed than those in the south  In the Americas, Canada and the United States are more developed than Mexico in the south  In Asia, South Korea's GDP is the sum of all the countries in Southeast Asia
Getting food is not the main mental activity of human beings
 The difference is due to the fact that the brain is further complicated by people in cold areas in order to survive, while people in the tropics lose the motivation to evolve further because of the abundance of food