Crosstalk in concurrent repeated games impedes direct reciprocity and requires stronger levels of forgiveness

• Published in: Nature communications 2018-02, Vol.9 (1), p.555-8, Article 555
• Main Authors: Reiter, Johannes G., Hilbe, Christian, Rand, David G., Chatterjee, Krishnendu, Nowak, Martin A.
• Format: Article
• Language: English
• Subjects: 631/181/2469; 631/378/2645/2646; 631/477/2811; 639/705/1041; Algorithms; Computer Simulation; Cooperation; Cooperative Behavior; Crosstalk; Forgiveness; Game Theory; Games; Humanities and Social Sciences; Humans; Interpersonal Relations; Models, Psychological; multidisciplinary; Population structure; Prisoner Dilemma; Reciprocity; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-017-02721-8

Direct reciprocity is a mechanism for cooperation among humans. Many of our daily interactions are repeated. We interact repeatedly with our family, friends, colleagues, members of the local and even global community. In the theory of repeated games, it is a tacit assumption that the various games that a person plays simultaneously have no effect on each other. Here we introduce a general framework that allows us to analyze “crosstalk” between a player’s concurrent games. In the presence of crosstalk, the action a person experiences in one game can alter the person’s decision in another. We find that crosstalk impedes the maintenance of cooperation and requires stronger levels of forgiveness. The magnitude of the effect depends on the population structure. In more densely connected social groups, crosstalk has a stronger effect. A harsh retaliator, such as Tit-for-Tat, is unable to counteract crosstalk. The crosstalk framework provides a unified interpretation of direct and upstream reciprocity in the context of repeated games. Social interactions among people are often repeated, and yet it is assumed that simultaneous interactions are independent from one another. Here, Reiter and colleagues describe a conceptual framework where an action in one game can influence the decision in another.