Steven Pinker's New York Times article of that name is definitely worth a read.
In it he argues that the universal human tendency to moralise has five main, culturally-variable drivers: Authority, Purity, Community, Fairness and Harm. In the west for example we tend to prioritise fairness over community in our commercial dealings, but this is not the case in other societies where nepotism and cronyism are more prevalent. He also looks at the ways that some things in our culture have become moralised (food, smoking) whilst others are effectively downgraded into lifestyle choices (divorce, homosexuality etc.).
Interestingly, he suspects that "there seems to be a Law of Conservation of Moralization, so that as old behaviours are taken out of the moralized column, new ones are added to it."
The article is also replete with fascinating thought experiments.