The mindset that Caleb is using to evaluate Greek behavior when comes back from a vacation in Greece and announces that Greeks are cold and unfriendly since they won't strike up conversations with him on the subways like what is done in the US is called an ethnocentric mindset.
Ethnocentric mindset is the mindset where a person judges another culture based on their predisposition that they can find in the standards and values of their own culture.
