Distrust alone cannot explain mafia origins in Sicily. [causal]
The mafia may be a solution, however perverse, to the problem of distrust, but it is not the only one. Some parts of the South found no solution at all, and these degenerated into miserable places in which to live. In the village explored by Edward Banfield (1958) lack of trust plainly remained uncompensated, while other towns, such as Pisticci (Davis 1975), developed a system of patronage rather than a mafia. Still others established pockets of civil society on a par with those throughout the rest of Italy. Hence, there must be some additional factor that accounts for the origin of the mafia.
Diego Gambetta, The Sicilian Mafia The Busi…, loc. 200