Research for this exhibition was supported by the Andrew W. Mellon Foundation, the Canada 150 Research Chairs Program, and the Columbia Graduate School of Architecture, Planning and Preservation. Thanks to Leslie Gill Architect for design consultation, and to the Columbia University Rare Book and Manuscript Library, Harriet Zuckerman, and Robert Lazarsfeld for assistance and reproduction permissions on archival materials.

Columbia University’s Center for Spatial Research investigates links between design, urbanism, the humanities, and data science. Homophily: The Urban History of an Algorithm is named after a term coined by researchers Paul Lazarsfeld and Robert Merton in an influential 1954 study of friendships in a public housing project in Pittsburgh. “Homophily” is “the tendency for friendships to form between people ‘of the same kind.’” Focusing on the residents’ attitudes toward racial integration versus segregation, the study concluded that close friendships form and persist not simply on the basis of shared racial identities but also thanks to shared values and beliefs. The model of homophily was born in the larger context of midcentury urban struggles over race and space in the United States, and this installation by the Center for Spatial Research looks at its legacy, presenting data visualizations that show its contemporary applications. What began as a formal explanation of social life in a housing complex has today become an algorithm that shapes social dynamics in digital space, driving everything from targeted advertising to movie and book recommendations to predictive policing on the streets of Chicago. It perpetuates a social world in which positions are reinforced and concentrated rather than challenged or hybridized.