Language is considered a cultural characteristic because
Social barrier effects consist of characteristics that differentiate human groups and potentially limit interaction between them, thus inhibiting the spread of culture. Examples include language, religion, race and ethnicity, and a history of conflict between specific cultural communities.). That also would be a culture region based on a single cultural component. In contrast, if you were teaching about Japan, you might ask your students to go down the list of cultural components and characterize the Japanese culture region with respect to religion, language, architecture, cuisine, and so forth.