The first thing you learn when studying different cultures is that there is no such thing as “normal”. For instance, what colour would a bride wear to a wedding, or to a funeral? Well – the answer is – depends. Nowadays, brides can wear pretty much anything they like and often do. Tradition has Western brides in white and often Eastern brides in red. White for many asian groups is for funerals.
Are you quiet in church or should you dance and wave your arms about? Depends.
Is it polite to look someone in the eyes while you are talking to them? Not if you are a woman talking to an older man, especially if he is not from your family. Ask any Muslim or traditional indigenous family.
Is it polite to burp, wipe your nose, show the soles of your feet, offer your left hand to someone? Well, again – it depends. So when you are writing, be sure that the responses your characters are offering are correct for their cultural beliefs. Don’t assume that if your cultural norm is to wear a bag on your head – so is everyone elses’.