Answer:
migrant diffusion.
Step-by-step explanation:
Migrant diffusion was the main mechanism by which folk customs spread to popular culture. Folk customs such as sports and music originated in small, limited regions that shared common cultural traits. Its global spread was limited by geographical and environmental barriers, as well as limited technology. Therefore, the main way in which these spread was through migrant diffusion. As people moved away from their places of origin, they took these traditions with them, spreading them to other areas of the world.