Deviation from social norms depends on three things
Time
Context
Culture
ERA
Into early 20th Century - criminals were executed in Britain
Equally, women were expected to do the housework while the man earned money
CONTEXT
Wearing sandals in winter is deviant, but not in summer
Wearing sunglasses at night is deviant, but not in the day
CULTURE
In one culture, it might be normal to marry as young as possible
In some countries, especially in Asia, the elderly are treated with huge amounts of respect. In others, that is not the case
In the Middle East, the thumbs up gesture is incredibly offensive
Keeps society under control. Social norms subconsciously keep us in order - things like queuing and manners keep things functioning, and without them, we wouldn't have as much of an orderly society.