‘Trust thy crooked neighbor’: Al Capone and the power of social networks

Nearly a century ago, the United States prohibited the production and distribution of alcohol through a constitutional amendment. The social experiment, known as Prohibition, lasted only 14 years, but it had the long-term consequence of strengthening organized crime, especially in cities like Chicago, giving rise to Chicago’s infamous Al Capone.

Capone’s criminal organization existed before the days of Facebook and Twitter, but the existence and prominence of the Capone’s Syndicate relied heavily on the power of social networks. A new study by sociologists from Yale and the University of California-Davis analyzed the role of these social networks during this time in U.S. history when the boundaries between the criminal and legitimate worlds dramatically shifted.

The researchers created a network database from more than 5,000 pages of historical documents located at multiple archives in Chicago. Co-authors Andrew V. Papachristos, associate professor of sociology at Yale, and Chris M. Smith, assistant professor of sociology at University of California-Davis, used this database to map Capone’s criminal and social networks. The study, recently published in the American Sociological Review, reveals how multiple types of relationships formed and sustained Capone’s Syndicate.

Papachristos and Smith discovered that the Chicago organized crime network contained more than 1,000 people whose criminal activities directly or indirectly connected them to Capone. However, the organized crime network also contained personal relationships, such as family members and friendships, and legitimate relationships that were completely legal but easily corruptible, such as co-owning businesses, political associations, or union associations.

“Our findings suggest that one method of organized crime’s integration into mainstream society is through multiplex social relationships,” says Papachristos. “When groups of ordinary bootleggers, brothel owners, and bookies organize and infiltrate police departments, courtrooms, unions, and political offices through overlapping and multiplex relationships, seemingly disparate social worlds collide and generate organized crime networks.”

“Multiplexity was rare but relevant,” says Smith. “It was incredibly important for generating organized crime. Although only 10% of the relationships between organized crime individuals contained multiplex ties, these overlapping relationships integrated the criminal, legitimate, and personal networks and were essential to the operation of organized crime.”

Multiplexity is an important characteristic of organized crime that generates both its unique character and a unique set of problems, note the sociologists. On the one hand, multiplexity organizes criminal groups’ pursuit of the American Dream through connections to the legitimate world. On the other hand, the costs of failure for multiplex ties are higher, as exposure can lead to apprehension or death. “Organized crime represents a unique case, because cultivating multiplex ties requires individuals to ‘trust thy crooked neighbor,’ a context in which quick cash and shady dealings require people to trust each other, even when corruption and violence are tools of the trade,” says Papachristos.

These findings have implications for the study of organized crime and the study of social networks more broadly, say the researchers. With regard to organized crime, the results highlight the ways multiplexity links the underworld and mainstream society — a process that organizes crime into mainstream society and, specifically, institutionalized Prohibition networks within the city of Chicago. The rarity of multiplexity highlights the difficulty of locating trustworthy bridges when one cannot trust just any crook, neighbor, or politician, even when multiplexity brought the spheres of organized crime together.

Papachristos notes that just mentioning Al Capone will drum up a lot of imagery. “Capone is a cultural force but at the same time he couldn’t have been without the network that he both inherited and created.”

A goal of the project, according to the researchers, was to address some of these challenges with the creation of a “Capone Database,” a relational dataset containing information on more than 3,000 individuals who were in some way connected to organized crime from 1900 to 1950, with the majority of these ties occurring during Prohibition. The database includes records from the Chicago Crime Commission, the Internal Revenue Service, the Federal Bureau of Investigation, the National Archives-Great Lakes Region, Northwestern’s Homicide in Chicago 1870 to 1930 database, the Proquest Historical Chicago Tribune, and John Landesco’s organized crime section of the Illinois Crime Survey of 1929.

“The Capone Database is remarkable in terms of size, content, and dynamics, both for the study of social networks more generally and the study of organized crime more specifically,” says Papachristos. “The database contains information on more than 100 different types of relationships that we are able to aggregate into various analytically meaningful categories. Exploring and analyzing multiplexity requires this fine-grained information on the content of relationships.

“We took network science — a cutting edge computational approach — and applied it to a historical sociological problem: Prohibition Era Chicago,” says Papachristos. “This research is at the intersection of history, social science, and computer science.”

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