In less developed societies with limited communication, spreading new sub-races occurs at a gradual pace. Once the defining characteristics of a sub-race are identified, the concept of unconscious selection suggests that these traits will tend to be emphasized over time, influenced by factors like current trends and regional cultural development.

This process of unconscious selection highlights how societal fashion and the level of civilization within a community can impact which features gain prominence in a sub-race. Thus, the evolution of these characteristics is not just a reflection of biological factors but is also intertwined with cultural dynamics.