- Sicily is blamed for the emergence of organized crime.
- Some Northern Italians also believe Sicilians are part Arab/North African, and thus, not really "European" (but as the other poster pointed out, that's not totally accurate - as there were invasions from the *North* as well).
- Sicilians are considerably more socially conservative and devout than most of Italy, presenting the stereotypical illusion in urbane places like Milan, Florence, and Rome that the island is "backward" and "mystical".
Thus, while most Italians are fond of rituals and traditions, Sicilians are looked down upon for actually believing the mumbo-jumbo, as it were. Instead of only paying it lip service like the others.
- These ideas are also coupled with the island's chronic poverty as a so-called explanation for Sicilian "inferiority" compared to the properous North. A bigoted notion for sure.
- Most Italian immigrants to the Americas are from Sicily: Including the largest communities on the U.S. East Coast and Midwest (New York, New Jersey, Illinois), and of course, Argentina.
Though certainly that's not always the case... the large Italian population in San Francisco, for instance, is mainly of Genoan and Florentine extraction (hence, SF never developed a powerful mafia).
- In truth, most of these perceived "differences" are silly prejudices, of course. Europe has always been multi-cultural, with lots of people mixing from throughout the Eurasian and African continents. Organized crime would be a problem even without Sicily. And Sicily is a geographically and culturally important part of Italy.