You are traveling abroad and encounter a society where people eat insects as a regular part of their diet. To them, insects are a nutritious and sustainable food source, but in your culture, eating insects is considered unappetizing and strange. When discussing this practice with your friends back home, one of them says, “That’s disgusting. How can they eat insects? Our way of eating is obviously better.” 

This example perfectly represents what anthropologists call "Prejudice Theory".