From 2000 to 2004, he was a professor of Learning and Instructional Technologies at the Faculty of Educational Sciences of the University of L’Aquila, and, since December 2016, he has been a professor of Communication Psychology at the International Telematic University UniNettuno. During these years he collaborated in Italy and abroad with Domenico Parisi, Stefano Nolfi, Andrea Di Ferdinando, Gunter Wagner, Frank Keil, Paolo Spada, James Fishkin, Mark Klein, Luca Iandoli, Ivana Quinto, Juan Pablo Neirotti, Federico Diano, Raffaele Di Fuccio; Fabrizio Ferrara, Franco Rubinacci, Riccardo Galbiati, Vito Gironda, Carlo Gallina, Cesare Giordano, Valerio Consalvi and Roberto Scandurra.
From 1988 to 2002, he was a member of the Center of Computational Ecology at Yale University, and since 2001 he has been an affiliate member of the New England Complex Systems Institute (Cambridge, MA). In 1997 Calabretta spent a sabbatical year as a postdoc at Yale University (collaborating with Gunter Wagner, then chair of the newly formed Department of Ecology and Evolutionary Biology); in 2000 and 2002 he returned to Yale as a Visiting Fellow of the Department of Ecology and Evolutionary Biology and of Psychology (also collaborating with Frank Keil, chair of the Department; Calabretta et al., 2008), and in 2010 as a Visiting Fellow of the Department of Psychology. His interdisciplinary research was the first at the international level in which it was possible to simulate the origin of modularity, and led to the discovery of new mechanisms for the origin of structural and functional modularity (Gunter Wagner, personal communication, March 19, 2001; see, e.g., Calabretta et al., 2000; Calabretta et al., 2003; Calabretta, 2007). In 2015 he published his last paper on modularity (Calabretta & Neirotti, 2015).
He was the co-editor of the English book From animals to animats 9: Proceedings of the Ninth International Conference on Simulation of Adaptive Behaviour (Springer Verlag, Berlin), together with Nolfi, Baldassarre, Hallam, Marocco, Meyer, Miglino and Parisi.
In 2012 he was a Visiting Scholar at Stanford University (collaborating with James Fishkin, chair of the Department of Communication and the Center for Deliberative Democracy; Fishkin & Calabretta, 2012). Calabretta is the creator of Doparie, a new methodology for decision-making within political parties. In the spring of 2016, he was invited back to Stanford and participated as a co-organizer in the first deliberative survey conducted among students on the Californian campus. He developed the theory of doparies in the Italian books Il film delle emozioni (2007, second edition) and Doparie dopo le primarie (Nutrimenti, 2010), while in 2011 he published the first scientific article on the subject (Calabretta, 2011). In early 2012, together with collaborators from the Harvard Kennedy School of Government (Paolo Spada) and MIT (Mark Klein), he organized and directed the first online dopary experiment (Klein, Spada & Calabretta, 2012). The article was published in 2018 by the renowned international journal New Media & Society (Iandoli et al., 2018). In November 2016 he organized and directed the first face-to-face dopary, focused on the topic of a possible exit of Italy from the Euro. The dopary took place at the Centro Sociale La Strada, in the Garbatella district of Rome (thanks to Franco Principi); two experts: Mauro Scarfone (in favor of remaining in the Euro) and Thomas Fazi (in favor of leaving the Euro); moderator: literary critic Filippo La Porta.
The national project Emotion.exe, funded by the Lazio Region, produced the software of the same name in 2020 (Diano, Ferrara & Calabretta, 2019; Di Fuccio, Di Ferdinando, Rubinacci, Ferrara, Diano & Calabretta, 2020 ).
(https://youtube.com/@rcalab?si=DrARRfmZjt9U)
