From Local to Global Dilemmas in Social Networks

Abstract

Social networks affect in such a fundamental way the dynamics of the population they support that the global, population-wide behavior that one observes often bears no relation to the individual processes it stems from. Up to now, linking the global networked dynamics to such individual mechanisms has remained elusive. Here we study the evolution of cooperation in networked populations and let individuals interact via a 2-person Prisoner's Dilemma – a characteristic defection dominant social dilemma of cooperation. We show how homogeneous networks transform a Prisoner's Dilemma into a population-wide evolutionary dynamics that promotes the coexistence between cooperators and defectors, while heterogeneous networks promote their coordination. To this end, we define a dynamic variable that allows us to track the self-organization of cooperators when co-evolving with defectors in networked populations. Using the same variable, we show how the global dynamics — and effective dilemma — co-evolves with the motifs of cooperators in the population, the overall emergence of cooperation depending sensitively on this co-evolution.

An Online Experimental Framework for Cooperative Relationships With a Real-Time Decision-Making and Rewarding Environment

“…It has also been shown that structures of social networks can influence the emergence of cooperative behavior (Nowak and May, 1992;Nowak, 2006;Pinheiro et al, 2012), theoretically. Recent experimental studies with interaction networks of human populations based on repeated games suggested that the population structure can affect the evolution of cooperative behavior as theoretically expected (Rand et al, 2014), or may not affect so significantly than theoretically expected (Grujić et al, 2014) because they might adopt different strategy updating criterions (e.g., moody conditional cooperation Grujić et al, 2014, reinforcement learning Horita et al, 2017 rather than an imitation-based criterion (e.g., imitating the best), which is a common assumption in theoretical models.…”

Reward from Punishment Does Not Emerge at All Costs

“…Popular mechanisms that aim at solving this evolutionary conundrum such as kin selection [17], direct reciprocity [13], [18], voluntary participation [19], [20], reputation [21]–[24], social structure [25]–[29], peer and pool punishment [30]–[40], etc , are able to promote cooperation by transforming a PD into a SH [4], [16], [41], [42]. From a sociological perspective, the SH portrays a milder dilemma when compared to the PD , since it strips temptation from the latter, leaving only fear in the way between individual and collective interest [43], [44].…”

Origin of Peer Influence in Social Networks

“…In the mean-field limit, in which everyone is equally likely to interact with anyone else (also known as well-mixed population approximation), this dilemma inexorably condemns cooperation to extinction [27], a fate which may change when individuals are embedded in a social network represented by means of a graph, in which structural diversity is ubiquitous [1][2][3]5,[7][8][9][10][22][23][24][25][26]28,[30][31][32][33][34][35].…”

“…Despite the importance of social networks in defining the paths and ends of the dynamical processes they support, showing how important it is to address and understand population dynamics from a complex networks perspective [5,10,32,33,37], the patterns of peer influence they exhibit are surprisingly independent of their structure. On the other hand, when networks are very sparse, different network properties may contribute to enlarge the sphere of influence of each individual.…”