There are many cultures within cultures in this world and we often assume that one subculture is different for the obvious reasons. Sure, many people who belong to one subculture might look a little different from those who exist in another culture. But this is where the obvious differences end. Many cultures within cultures have their own set of hierarchy and their own set of laws and rules. You can’t just walk into the culture and break these rules. You have to get to know them first and you must abide by them regardless of your own culture.
When one culture collides with another, there is usually a bit of tension and someone ends up either breaking through the tension or settling it with violence. In many ways, the culture who has been disturbed sets up the rules for how things are going to happen when they are disrupted. This is, in many cases, a large reason why there are so many cultures within cultures. This allows for some sort of reigning culture that can tell the others how and why they should respond to certain influences. The smaller cultures can create additional subcultures, and so on down the line to weed out the most dedicated and the most pinpointed, honed, culture expert within one community. It can be a little scary to enter a subculture you know nothing about, as mistakes are not always easily forgiven and there is no guarantee that you will understand the rules in the early part of your visit.