“ A culture must hide its hands in the arm of their clothing as a sign of respect and peace. When approaching somebody you show them respect by crossing your arms and hiding the hands in the shirt sleeves. Nobody worries about hidden knives and such, it is the threat of magic that this custom was created to prevent.”
“ A certain tribe in a valley believes that the soul remains trapped in the body after death and is aware of it. So they treat their dead as if they are alive, talking to them and keeping them at home. They are used to the stink and for some reason are also immune to the diseases that this practise causes but outsiders are not so lucky.”
“ A people who believe it is incredibly impolite to speak to anybody they meet for the first time. They believe their actions should speak for them until they are comfortable in each others presence and can then trust each other. Only then would converstation be appropriate.”