Why are the peoples of the Earth not developing at the same rate?

Why are the peoples of the Earth not developing at the same rate? How do relations between peoples influence the process of their development?

In my opinion, everything depends on the desire of a particular nation to develop. The better the attitude, the stronger the development (example: supply of new products from abroad).
A less developed people borrows not only the positive results of the evolution of a more developed people, but also a lot of negative manifestations of development.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.