Culture in terms of Middle-earth, refers to the cumulative deposit of knowledge, experience, beliefs, values, attitudes, meanings, hierarchies, religion, notions of time, roles, spatial relations, concepts of the world, and material objects and possessions acquired by a group of people in the course of generations through individual and group striving.
Due to the mass amount of history in Middle-earth, culture changes. The major cause of certain cultures is due to where groups of peoples come from, where their ancestors come, what languages they speak, where a language has roots in, and what race they are. For example Dwarves, naturally like mining and mountainsm therefore that is where they live and build their homes out of. Also for example the elves have many historic roots and each have their own language which shapes what architecture they build and what clothes and armor they wear.