The spread of cultural traits (such as good and ideas) can be identified as the exchange of ideas ig. Ex,, when a merchant is traveling to sell their goods they also exchanged their cultural traits or something they may have. Like learning a new language/religion/ or technology. The two merchants exchange something and also learn something from the other merchant or get encouraged to try something the other merchant does on a daily basis. Then they would maybe tell their family/friends about maybe the religion they learned from the other merchant and it spreads and spreads from people to people until you get something called cultural diffusion.
