Codes of the Underworld: How Criminals Communicate

Bada-bing. For some people, The Godfather is no mere movie but a manual – a guide to living the gangster's life. They lap up all that stuff about going to the mattresses and sleeping with the fishes. The famous scene in which a mafia refusenik wakes up next to a horse's head may be macabre make-believe, but in some quarters it's treated like a tutorial.

So who are these apparent innocents taking their cues from Hollywood? None other than the mafia themselves, writes Diego Gambetta in his new book, Codes of the Underworld: How Criminals Communicate. The Oxford sociologist offers example upon example of gangsters apeing Francis Ford Coppola's masterpiece – or what he calls "lowlife imitating art".

There's the Don who took over a Sicilian aristocrat's villa for his daughter's wedding – with 500 guests revelling to the film's soundtrack; the building contractors of Palermo who receive severed horse's heads if they get in the mob's way; and John Gotti's former lieutenant, Salvatore "Sammy the Bull" Gravano, who confessed that plagiarism ranked among his (lesser) crimes: "I would always tell people, just like in The Godfather, 'If you have an enemy, that enemy becomes my enemy.'"

Yet Mario Puzo, The Godfather's inventor, admitted that he "never met a real honest-to-God gangster", while many of the film's most quotable lines (remember "Leave the gun. Take the cannoli"?) were improvised. So what accounts for its influence not just among the mafia but with Hong Kong triads, Japanese yakuza and Russian mobsters?

Well, strip away the mystique and organised crime is a business – one with big handicaps. It may be called "the Firm", but managing a poorly educated, violent workforce is a challenge, advertising job vacancies only attracts the law, and appraisals for underperforming staff can err on the brusque side. The Godfather and other gangster movies plug those holes, says Gambetta. They give criminals an easy-to-follow protocol and a glamour that serves as both corporate feelgood and marketing tool. Uncomfortable though it may be to acknowledge, the underworld is not above taking its cues from the upperworld.

Thanks to Aditya Chakrabortty