1. Reputation and reciprocity : reviewChengyi Xia, Juan Wang, Matjaž Perc, Zhen Wang, 2023, pregledni znanstveni članek Opis: Reputation and reciprocity are key mechanisms for cooperation in human societies, often going hand in hand to favor prosocial behavior over selfish actions. Here we review recent researches at the interface of physics and evolutionary game theory that explored these two mechanisms. We focus on image scoring as the bearer of reputation, as well as on various types of reciprocity, including direct, indirect, and network reciprocity. We review different definitions of reputation and reciprocity dynamics, and we show how these affect the evolution of cooperation in social dilemmas. We consider first-order, second-order, as well as higherorder models in well-mixed and structured populations, and we review experimental works that support and inform the results of mathematical modeling and simulations. We also provide a synthesis of the reviewed researches along with an outlook in terms of six directions that seem particularly promising to explore in the future. Ključne besede: pattern formation, Monte Carlo method, complex network, evolutionary game theory, cooperation, social physics Objavljeno v DKUM: 20.06.2024; Ogledov: 111; Prenosov: 6 Celotno besedilo (4,71 MB) Gradivo ima več datotek! Več... |
2. Turing patterns in simplicial complexesShupeng Gao, Lili Chang, Matjaž Perc, Zhen Wang, 2023, izvirni znanstveni članek Opis: The spontaneous emergence of patterns in nature, such as stripes and spots, can be mathematically explained by reaction-diffusion systems. These patterns are often referred as Turing patterns to honor the seminal work of Alan Turing in the early 1950s. With the coming of age of network science, and with its related departure from diffusive nearest-neighbor interactions to long-range links between nodes, additional layers of complexity behind pattern formation have been discovered, including irregular spatiotemporal patterns. Here we investigate the formation of Turing patterns in simplicial complexes, where links no longer connect just pairs of nodes but can connect three or more nodes. Such higher-order interactions are emerging as a new frontier in network science, in particular describing group interaction in various sociological and biological systems, so understanding pattern formation under these conditions is of the utmost importance. We show that a canonical reaction-diffusion system defined over a simplicial complex yields Turing patterns that fundamentally differ from patterns observed in traditional networks. For example, we observe a stable distribution of Turing patterns where the fraction of nodes with reactant concentrations above the equilibrium point is exponentially related to the average degree of 2-simplexes, and we uncover parameter regions where Turing patterns will emerge only under higher-order interactions, but not under pairwise interactions. Ključne besede: Turing pattern, higher-order network, nonlinear dynamics, pattern formation Objavljeno v DKUM: 31.05.2024; Ogledov: 148; Prenosov: 4 Celotno besedilo (1,57 MB) Gradivo ima več datotek! Več... |
3. Self-organization towards optimally interdependent networks by means of coevolutionZhen Wang, Attila Szolnoki, Matjaž Perc, 2014, izvirni znanstveni članek Opis: Coevolution between strategy and network structure is established as a means to arrive at the optimal conditions needed to resolve social dilemmas. Yet recent research has highlighted that the interdependence between networks may be just as important as the structure of an individual network. We therefore introduce the coevolution of strategy and network interdependence to see whether this can give rise to elevated levels of cooperation in the prisonerʼs dilemma game. We show that the interdependence between networks self-organizes so as to yield optimal conditions for the evolution of cooperation. Even under extremely adverse conditions, cooperators can prevail where on isolated networks they would perish. This is due to the spontaneous emergence of a two-class society, with only the upper class being allowed to control and take advantage of the interdependence. Spatial patterns reveal that cooperators, once arriving at the upper class, are much more competent than defectors in sustaining compact clusters of followers. Indeed, the asymmetric exploitation of interdependence confers to them a strong evolutionary advantage that may resolve even the toughest of social dilemmas. Ključne besede: coevolution, cooperation, interdependent networks, evolutionary games, collective phenomena, self-organization, phase transitions, physics of social systems Objavljeno v DKUM: 03.07.2017; Ogledov: 1297; Prenosov: 415 Celotno besedilo (887,51 KB) Gradivo ima več datotek! Več... |
4. Wisdom of groups promotes cooperation in evolutionary social dilemmasAttila Szolnoki, Zhen Wang, Matjaž Perc, 2012, izvirni znanstveni članek Opis: Whether or not to change strategy depends not only on the personal success of each individual, but also on the success of others. Using this as motivation, we study the evolution of cooperation in games that describe social dilemmas, where the propensity to adopt a different strategy depends both on individual fitness as well as on the strategies of neighbors. Regardless of whether the evolutionary process is governed by pairwise or group interactions, we show that plugging into the wisdom of groups strongly promotes cooperative behavior. The more the wider knowledge is taken into account the more the evolution of defectors is impaired. We explain this by revealing a dynamically decelerated invasion process, by means of which interfaces separating different domains remain smooth and defectors therefore become unable to efficiently invade cooperators. This in turn invigorates spatial reciprocity and establishes decentralized decision making as very beneficial for resolving social dilemmas. Ključne besede: cooperation, public goods, wisdom of crowds, phase transitions, physics of social systems Objavljeno v DKUM: 23.06.2017; Ogledov: 1329; Prenosov: 394 Celotno besedilo (646,99 KB) Gradivo ima več datotek! Več... |
5. Optimal interdependence between networks for the evolution of cooperationZhen Wang, Attila Szolnoki, Matjaž Perc, 2013, izvirni znanstveni članek Opis: Recent research has identified interactions between networks as crucial for the outcome of evolutionary games taking place on them. While the consensus is that interdependence does promote cooperation by means of organizational complexity and enhanced reciprocity that is out of reach on isolated networks, we here address the question just how much interdependence there should be. Intuitively, one might assume the more the better. However, we show that in fact only an intermediate density of sufficiently strong interactions between networks warrants an optimal resolution of social dilemmas. This is due to an intricate interplay between the heterogeneity that causes an asymmetric strategy flow because of the additional links between the networks, and the independent formation of cooperative patterns on each individual network. Presented results are robust to variations of the strategy updating rule, the topology of interdependent networks, and the governing social dilemma, thus suggesting a high degree of universality. Ključne besede: social dilemma, cooperation, public goods, biased utility, interdependent networks, statistical physics of social systems Objavljeno v DKUM: 23.06.2017; Ogledov: 1195; Prenosov: 380 Celotno besedilo (658,72 KB) Gradivo ima več datotek! Več... |
6. Interdependent network reciprocity in evolutionary gamesZhen Wang, Attila Szolnoki, Matjaž Perc, 2013, izvirni znanstveni članek Opis: Besides the structure of interactions within networks, also the interactions between networks are of the outmost importance. We therefore study the outcome of the public goods game on two interdependent networks that are connected by means of a utility function, which determines how payoffs on both networks jointly influence the success of players in each individual network. We show that an unbiased coupling allows the spontaneous emergence of interdependent network reciprocity, which is capable to maintain healthy levels of public cooperation even in extremely adverse conditions. The mechanism, however, requires simultaneous formation of correlated cooperator clusters on both networks. If this does not emerge or if the coordination process is disturbed, network reciprocity fails, resulting in the total collapse of cooperation. Network interdependence can thus be exploited effectively to promote cooperation past the limits imposed by isolated networks, but only if the coordination between the interdependent networks is not disturbed. Ključne besede: social dilemma, cooperation, public goods, biased utility, interdependent networks, statistical physics of social systems Objavljeno v DKUM: 23.06.2017; Ogledov: 1260; Prenosov: 394 Celotno besedilo (741,04 KB) Gradivo ima več datotek! Več... |
7. If players are sparse social dilemmas are too: importance of percolation for evolution of cooperationZhen Wang, Attila Szolnoki, Matjaž Perc, 2012, izvirni znanstveni članek Opis: Spatial reciprocity is a well known tour de force of cooperation promotion. A thorough understanding of the effects of different population densities is therefore crucial. Here we study the evolution of cooperation in social dilemmas on different interaction graphs with a certain fraction of vacant nodes. We find that sparsity may favor the resolution of social dilemmas, especially if the population density is close to the percolation threshold of the underlying graph. Regardless of the type of the governing social dilemma as well as particularities of the interaction graph, we show that under pairwise imitation the percolation threshold is a universal indicator of how dense the occupancy ought to be for cooperation to be optimally promoted. We also demonstrate that myopic updating, due to the lack of efficient spread of information via imitation, renders the reported mechanism dysfunctional, which in turn further strengthens its foundations. Ključne besede: cooperation, public goods, punishment, phase transitions, physics of social systems Objavljeno v DKUM: 23.06.2017; Ogledov: 1246; Prenosov: 367 Celotno besedilo (413,53 KB) Gradivo ima več datotek! Več... |
8. Heterogeneous aspirations promote cooperation in the prisoner's dilemma gameMatjaž Perc, Zhen Wang, 2010, izvirni znanstveni članek Opis: To be the fittest is central to proliferation in evolutionary games. Individuals thus adopt the strategies of better performing players in the hopeof successful reproduction. In structured populations the array of those that are eligible to act as strategy sources is bounded to the immediate neighbors of each individual. But which one of these strategy sources should potentially be copied? Previous research dealt with this question either by selecting the fittest or by selecting one player uniformly at random. Here we introduce a parameter that interpolates between these two extreme options. Setting equal to zero returns the random selection of the opponent, while positive favor the fitter players. In addition, we divide the population intotwo groups. Players from group select their opponents as dictated by the parameter , while players from group do so randomly irrespective of . We denote the fraction of players contained in groups and by and , respectively. The two parameters and allow us to analyze in detail how aspirations in the context of the prisoner's dilemma game influence the evolution of cooperation. We find that for sufficiently positive values of there exist a robust intermediate for which cooperation thrives best. The robustness of this observation is tested against different levels of uncertainty in the strategy adoption process and for different interaction networks. We also provide complete phase diagrams depicting the dependence of the impact of and for different values of , and contrast the validity of ourconclusions by means of an alternative model where individual aspiration levels are subject to evolution as well. Our study indicates that heterogeneity in aspirations may be key for the sustainability of cooperation in structured populations. Ključne besede: evolutionary game theory, prisoner's dilemma, spatial games, aspirations, social systems, physics and society Objavljeno v DKUM: 19.06.2017; Ogledov: 1432; Prenosov: 378 Celotno besedilo (822,95 KB) Gradivo ima več datotek! Več... |