It is polite to bow. Just how far down you bow depends on the status of the person in question ? you needn ' t get down on your hands and knees, but a slight nod of the head is generally appropriate. If you drink with seniors, you should turn your shoulder sideways and drink unless they allow you to face to face each other. In any social unit there are accepted rules of behavior upheld. There are also norms of behavior mandated by custom and enforced by group pressure. An offender faces no formal trial or sentence for breach of etiquette; the penalty lies in the disapproval of other members of the group. Regardless of its level of material culture, any highly stratified society will possess an etiquette in which every person knows the behavior expected from him toward others and from other toward himself. Nonetheless, etiquette remains active on royal or ceremonial occasions and in the more formal aspects of professional or communal life. Since the framework and content of the communities of which society is formed are constantly changing, the habits of etiquette can and do change with them.