Ethnocentrism is the belief that one's own culture is superior to all others. It is a form of prejudice that can lead to discrimination and conflict. In this case, the person who criticizes the Amish farmer is exhibiting ethnocentrism by assuming that the Amish farmer's way of life is inferior to their own. They are judging the Amish farmer based on their own cultural values and beliefs, rather than trying to understand the Amish farmer's perspective.