For example, if you are an Irish person, do you feel more of a connection to people from the UK compared to people in other EU countries like France or Germany? Similar question for Croatians with Bosnians or Poles with Ukrainians or any other combination of nationalities.
How much does language play into that as a factor? For example, where I live in the United States, I'm technically closer geographically to Mexico or many Caribbean nations, but I still feel closer culturally to Canadians because we speak the same language and many famous "American" celebrities are actually Canadian. Not to say that I don't feel close to Mexicans culturally, but Canadians and Americans seem to me to have many more similarities.