Different cultures. That can include language, traditions, clothing, food, natural resources, government, arts, hobbies, ...
I believe the answer is: Familiarity
In this context, familiarity refers to psychological phenomenon that cause people to develop preference toward a certain thing because they see it often.
This happen when people experience repeated exposure toward things and started to develop interest/attraction toward that thing.
Both Genders being allowed to vote. Women allowed to work in so called men’s jobs like in factory
