Conflicts between groups are among the most challenging problems of mankind. They arise as groups... more Conflicts between groups are among the most challenging problems of mankind. They arise as groups compete for the possession of certain scarce resources. Under what conditions does such competition lead to conflict or to a peaceful coexistence? Why do individual group members, despite the likelihood of being harmed, voluntarily become involved in conflicts? Social Networks and Intergroup Conflict explores how decisions of individuals in competitive intergroup relations are influenced by their social network and by a common past and future. Social network effects are studied with a specific focus on the segregation effect. It is shown how these effects arise from individual actions that are constrained by social control which takes place in the individuals network neighborhood. The study reveals conditions under which social control has positive or negative effects on individual participation in conflict. It shows the mechanisms through which social control operates and affects intergroup relations. In repeated interactions it is analyzed how and to what extent individuals apply behavioral heuristics that are driven by past experience or are based on future expectations. This study examines these questions using analytical, computer simulation and experimental tools in order to promote methods of conflict resolution.
Ezt talán mi sem bizonyítja jobban, mint az a tény, hogy csak 1995-ben sikerült tetszőleges jelze... more Ezt talán mi sem bizonyítja jobban, mint az a tény, hogy csak 1995-ben sikerült tetszőleges jelzett gráfra az ilyen típusú kiegyensúlyozottság-index általános matematikai alakját véglegesen kidolgozni. Lásd: [13] Hummon-Fararo 1995. 18 A kétféle-relációjelzet-megváltoztató ill. relációmegszüntető-módszer azonosságának bizonyításához lásd: [10] Harary et al. 1965. 19 A 3. ábrán szereplő nyolc alapesetből Davis definíciója szerint tehát öt kiegyensúlyozott, és három kiegyensúlyozatlan. 20 Ha k=2, akkor kapjuk meg az első struktúratételt.
Brokerage is a central concept in the organization literature. It has been argued that individual... more Brokerage is a central concept in the organization literature. It has been argued that individuals in broker positions—i.e., connecting otherwise disconnected parts within a firm’s social network—can control the flow of information. It would imply their increased relevance in workplace gossip. This allegation, however, has not been addressed empirically yet. To fill this gap, we apply social network analysis techniques to relational data from six organizations in Hungary. First, we identify informal groups and individuals in broker positions. Then, we use this information to predict the likelihood with which positive or negative gossip is reported. We find more gossip when the sender and receiver are part of the same group and more positive gossip about in-group rather than out-group targets. Individuals in broker positions are more likely the senders and targets of negative gossip. Finally, even if both the brokers and the boss(es) are the targets of their colleagues’ negative goss...
A kamaszok körében tapasztalható intenzív státuszverseny egyik gyakori velejárója a pletykálkodás... more A kamaszok körében tapasztalható intenzív státuszverseny egyik gyakori velejárója a pletykálkodás, amit a fiatalok gyakran használnak eszközként a csoporton belüli magasabb státusz elérésére. Ha valakiről sok negatív pletyka terjed, az előbb vagy utóbb veszít megbecsültségéből. Az alacsony megbecsültséggel rendelkező kamaszokról továbbá egyre több negatív pletyka terjedhet el. Ugyanakkor a gyakori pletykálás is vezethet alacsonyabb megbecsültséghez. Ezeknek a lehetséges folyamatoknak az elemzésére egy magyarországi középiskolai panel adatfelvétel (7 iskola, 40 osztály, NT1=1313) első három hullámának kapcsolathálózati adatait használtuk fel. A pletyka- és a reputációs hálózatok leíró statisztikai és korrelációs elemzése mellett hét gimnáziumi osztály esetében sztochasztikus aktororientált modellek segítségével vizsgáltuk a kamaszok pletyka- és reputációs hálózatának együttes változását. Igazolódott az a feltételezés, hogy a kamaszok hajlamosak idővel lenézni azokat a társaikat, akik...
"The vast majority of R&D organizations face the problem of holding valuable knowledge e... more "The vast majority of R&D organizations face the problem of holding valuable knowledge embodied in highly educated and specialized employees in house. Previous research describes social structure in which employees are embedded as one of the important determinants of career expectations. In an empirical study of 44 R&D teams in the Netherlands this issue is investigated. The results imply that the expectation to stay in the R&D team is determined positively by social closure, whereas the expectation to stay in the organization is determined positively by the efficiency and effectiveness of individual social networks. Conclusions highlight that situational-depending HRM strategies are required for holding costly R&D staff in house."
Philosophical Transactions of the Royal Society B: Biological Sciences, 2021
Gossip is believed to be an informal device that alleviates the problem of cooperation in humans.... more Gossip is believed to be an informal device that alleviates the problem of cooperation in humans. Communication about previous acts and passing on reputational information could be valuable for conditional action in cooperation problems and pose a punishment threat to defectors. It is an open question, however, what kind of mechanisms can make gossip honest and credible and reputational information reliable, especially if intense competition for reputations does not exclusively dictate passing on honest information. We propose two mechanisms that could support the honesty and credibility of gossip under such a conflict of interest. One is the possibility of voluntary checks of received evaluative information from different sources and the other is social bonding between the sender and the receiver. We tested the efficiency of cross-checking and social bonding in a laboratory experiment where subjects played the Prisoner's Dilemma with gossip interactions. Although individuals ha...
Humans are capable of solving cooperation problems following social norms. Social norms dictate a... more Humans are capable of solving cooperation problems following social norms. Social norms dictate appropriate behaviour and judgement on others in response to their previous actions and reputation. Recently, the so-called leading eight norms have been identified from many potential social norms that can sustain cooperation through a reputation-based indirect reciprocity mechanism. Despite indirect reciprocity being claimed to extend direct reciprocity in larger populations where direct experiences cannot be accumulated, the success of social norms have been analysed in models with global information and evolution. This study is the first to analyse the leading eight norms with local information and evolution. We find that the leading eight are robust against selfish players within most scenarios and can maintain a high level of cooperation also with local information and evolution. In fact, local evolution sustains cooperation under a wider set of conditions than global evolution, whi...
High school track choice determines college access in many countries. We hypothesize that some qu... more High school track choice determines college access in many countries. We hypothesize that some qualified students avoid the college-bound track in high school simply because they overestimate admission requirements. To test this hypothesis, we conducted a randomized field experiment that communicated the admission standards of local secondary schools on the academic track to students in Hungary before the application deadline. We targeted the subset of students (“seeds”) who occupied the most central position in the classroom-social networks, aiming to detect both direct effects on the track choice of targeted seeds and spillover effects on their untreated peers. We found neither a direct effect nor a spillover effect on students’ applications or admissions on average. Further analyses, however, revealed theoretically plausible heterogeneity in the direct causal effect of the intervention on the track choice of targeted seeds. Providing information about admission standards increase...
Journal of Artificial Societies and Social Simulation, 2019
Traditional desegregation policies have improved but not fully solved the problems associated wit... more Traditional desegregation policies have improved but not fully solved the problems associated with the reproduction of inequalities and interracial prejudice in schools. This is partly because social networks are inherently segregated within integrated schools and the benefits of contact have not fully materialized. Therefore, new kinds of policies are needed to further improve the situation. This paper investigates the consequences and e iciency of seating arrangements on academic outcomes and prejudice using an agent-based model that reflects real-life asymmetries. We model interpersonal dynamics and study behavior in the classroom in the hypothetical case of a single teacher who defines students' seating arrangements. The model incorporates the mechanisms of peer influence on study behavior, on attitude formation, and homophilous selection in order to depict the interrelated dynamics of networks, behavior, and attitudes. We compare various seating arrangement scenarios and observe how GPA distribution and level of prejudice changes over time. Results highlight the advantages and disadvantages of seating strategies. In general, more heterogeneous deskmate pairs lead to a lower level of inequality and prejudice in the classroom, but this strategy does not favor talent management. Further, we evaluate outcomes compared to the absence of external intervention whereby students choose their own deskmates based on homophilous selection. Our model takes into account the fact that homophilous selection may be distorted due to the 'Acting White' phenomenon and pre-existing prejudice. Accounting for these factors implies slower convergence between advantaged and disadvantaged students.
How and why animals and humans signal reliably is a key issue in biology and social sciences. For... more How and why animals and humans signal reliably is a key issue in biology and social sciences. For many years the dominant paradigm in biology was the Handicap Principle. It claims a causal relationship between honesty and signal cost and thus predicts that honest signals have to be costly to produce. However, contrary to the Handicap Principle, game theoretical models predict that honest signaling is maintained by condition dependent signaling trade-offs and honest signals need not be costly at the equilibrium. Due to the difficulties of manipulating signal cost and signal trade-offs there is surprisingly little evidence to test these predictions either from biology or from social sciences. Here we conduct a human laboratory experiment with a two-factorial design to test the role of equilibrium signal cost vs. signalling trade-offs in the maintenance of honest communication. We have found that the trade-off condition has much higher influence on the reliability of communication than...
1 tudományos segédmunkatárs, mTa Társadalomtudományi Kutatóközpont "lendület" rECENS Kutatócsopor... more 1 tudományos segédmunkatárs, mTa Társadalomtudományi Kutatóközpont "lendület" rECENS Kutatócsoport 2 tudományos segédmunkatárs, mTa Társadalomtudományi Kutatóközpont "lendület" rECENS Kutatócsoport 3 kutató, mTa Társadalomtudományi Kutatóközpont "lendület" rECENS Kutatócsoport 4 tudományos segédmunkatárs, mTa Társadalomtudományi Kutatóközpont "lendület" rECENS Kutatócsoport, egyetemi tanársegéd, Szegedi Tudományegyetem Bölcsészettudományi Kar orosz Filológiai Tanszék 5 PhD, az mTa Társadalomtudományi Kutatóközpont "lendület" rECENS Kutatócsoport vezetője
Our study contributes to the debate on the evolution of cooperation in the singleshot Prisoner's ... more Our study contributes to the debate on the evolution of cooperation in the singleshot Prisoner's Dilemma (PD) played on networks. We construct a model in which individuals are connected with positive and negative ties. Some agents play signdependent strategies that use the sign of the relation as a shorthand for determining appropriate action toward the opponent. In the context of our model in which network topology, agent strategic types and relational signs coevolve, the presence of signdependent strategies catalyzes the evolution of cooperation. We highlight how the success of cooperation depends on a crucial aspect of implementation: whether we apply parallel or sequential strategy update. Parallel updating, with averaging of payoffs across interactions in the social neighborhood, supports cooperation in a much wider set of parameter values than sequential updating. Our results cast doubts about the realism and generalizability of models that claim to explain the evolution of cooperation but implicitly assume parallel updating.
Previous research describes social structure in which employees are embedded as one of the import... more Previous research describes social structure in which employees are embedded as one of the important determinants of intra-organizational career expectations. There are two contradictory arguments in the literature, however. First, social closure of informal relations is supposed to strengthen the intentions of staying. Second, the efficiency and effectivity of the individual social network is assumed to enhance in-house career expectations. This empirical study analyzed data from 44 R&D teams in the Netherlands. Multilevel analysis was used to separate individual and team influences. Results show that the prospects to stay in the R&D team are determined positively by social closure, whereas the expectation to stay in the organization is determined positively by the efficiency and effectivity of individual social networks. The conclusions highlight that different forms of social capital might be important for different types of career perspectives.
Dense in-group and scarce out-group relations (network segregation) often support the emergence o... more Dense in-group and scarce out-group relations (network segregation) often support the emergence of conflicts between groups. A key underlying mechanism is social control that helps to overcome the collective action problem within groups, but contributes to harmful conflicts among them in segregated settings. In this study, a new experimental design is introduced to test whether internalized social control affects contribution decisions in intergroup-related collective action. Subjects played single-shot Intergroup Public Good games in two groups of five each without communication. Subjects were connected via computers and connection patterns were manipulated to detect forms of social control that are activated conditional on expectations and on the composition of the artificially created ego-network. Results confirm the influence of behavioral confirmation and the conditional impact of internalized traitor and selective incentives. As an aggregated consequence of these social control effects, harmful intergroup outcomes were least likely when members of the groups were arranged in a mixed network.
The evolution of unconditional cooperation is one of the fundamental problems in science. A new s... more The evolution of unconditional cooperation is one of the fundamental problems in science. A new solution is proposed to solve this puzzle. We treat this issue with an evolutionary model in which agents play the Prisoner's Dilemma on signed networks. The topology is allowed to co-evolve with relational signs as well as with agent strategies. We introduce a strategy that is conditional on the emotional content embedded in network signs. We show that this strategy acts as a catalyst and creates favorable conditions for the spread of unconditional cooperation. In line with the literature, we found evidence that the evolution of cooperation most likely occurs in networks with relatively high chances of rewiring and with low likelihood of strategy adoption. While a low likelihood of rewiring enhances cooperation, a very high likelihood seems to limit its diffusion. Furthermore, unlike in non-signed networks, cooperation becomes more prevalent in denser topologies.
Conflicts between groups are among the most challenging problems of mankind. They arise as groups... more Conflicts between groups are among the most challenging problems of mankind. They arise as groups compete for the possession of certain scarce resources. Under what conditions does such competition lead to conflict or to a peaceful coexistence? Why do individual group members, despite the likelihood of being harmed, voluntarily become involved in conflicts? Social Networks and Intergroup Conflict explores how decisions of individuals in competitive intergroup relations are influenced by their social network and by a common past and future. Social network effects are studied with a specific focus on the segregation effect. It is shown how these effects arise from individual actions that are constrained by social control which takes place in the individuals network neighborhood. The study reveals conditions under which social control has positive or negative effects on individual participation in conflict. It shows the mechanisms through which social control operates and affects intergroup relations. In repeated interactions it is analyzed how and to what extent individuals apply behavioral heuristics that are driven by past experience or are based on future expectations. This study examines these questions using analytical, computer simulation and experimental tools in order to promote methods of conflict resolution.
Ezt talán mi sem bizonyítja jobban, mint az a tény, hogy csak 1995-ben sikerült tetszőleges jelze... more Ezt talán mi sem bizonyítja jobban, mint az a tény, hogy csak 1995-ben sikerült tetszőleges jelzett gráfra az ilyen típusú kiegyensúlyozottság-index általános matematikai alakját véglegesen kidolgozni. Lásd: [13] Hummon-Fararo 1995. 18 A kétféle-relációjelzet-megváltoztató ill. relációmegszüntető-módszer azonosságának bizonyításához lásd: [10] Harary et al. 1965. 19 A 3. ábrán szereplő nyolc alapesetből Davis definíciója szerint tehát öt kiegyensúlyozott, és három kiegyensúlyozatlan. 20 Ha k=2, akkor kapjuk meg az első struktúratételt.
Brokerage is a central concept in the organization literature. It has been argued that individual... more Brokerage is a central concept in the organization literature. It has been argued that individuals in broker positions—i.e., connecting otherwise disconnected parts within a firm’s social network—can control the flow of information. It would imply their increased relevance in workplace gossip. This allegation, however, has not been addressed empirically yet. To fill this gap, we apply social network analysis techniques to relational data from six organizations in Hungary. First, we identify informal groups and individuals in broker positions. Then, we use this information to predict the likelihood with which positive or negative gossip is reported. We find more gossip when the sender and receiver are part of the same group and more positive gossip about in-group rather than out-group targets. Individuals in broker positions are more likely the senders and targets of negative gossip. Finally, even if both the brokers and the boss(es) are the targets of their colleagues’ negative goss...
A kamaszok körében tapasztalható intenzív státuszverseny egyik gyakori velejárója a pletykálkodás... more A kamaszok körében tapasztalható intenzív státuszverseny egyik gyakori velejárója a pletykálkodás, amit a fiatalok gyakran használnak eszközként a csoporton belüli magasabb státusz elérésére. Ha valakiről sok negatív pletyka terjed, az előbb vagy utóbb veszít megbecsültségéből. Az alacsony megbecsültséggel rendelkező kamaszokról továbbá egyre több negatív pletyka terjedhet el. Ugyanakkor a gyakori pletykálás is vezethet alacsonyabb megbecsültséghez. Ezeknek a lehetséges folyamatoknak az elemzésére egy magyarországi középiskolai panel adatfelvétel (7 iskola, 40 osztály, NT1=1313) első három hullámának kapcsolathálózati adatait használtuk fel. A pletyka- és a reputációs hálózatok leíró statisztikai és korrelációs elemzése mellett hét gimnáziumi osztály esetében sztochasztikus aktororientált modellek segítségével vizsgáltuk a kamaszok pletyka- és reputációs hálózatának együttes változását. Igazolódott az a feltételezés, hogy a kamaszok hajlamosak idővel lenézni azokat a társaikat, akik...
"The vast majority of R&D organizations face the problem of holding valuable knowledge e... more "The vast majority of R&D organizations face the problem of holding valuable knowledge embodied in highly educated and specialized employees in house. Previous research describes social structure in which employees are embedded as one of the important determinants of career expectations. In an empirical study of 44 R&D teams in the Netherlands this issue is investigated. The results imply that the expectation to stay in the R&D team is determined positively by social closure, whereas the expectation to stay in the organization is determined positively by the efficiency and effectiveness of individual social networks. Conclusions highlight that situational-depending HRM strategies are required for holding costly R&D staff in house."
Philosophical Transactions of the Royal Society B: Biological Sciences, 2021
Gossip is believed to be an informal device that alleviates the problem of cooperation in humans.... more Gossip is believed to be an informal device that alleviates the problem of cooperation in humans. Communication about previous acts and passing on reputational information could be valuable for conditional action in cooperation problems and pose a punishment threat to defectors. It is an open question, however, what kind of mechanisms can make gossip honest and credible and reputational information reliable, especially if intense competition for reputations does not exclusively dictate passing on honest information. We propose two mechanisms that could support the honesty and credibility of gossip under such a conflict of interest. One is the possibility of voluntary checks of received evaluative information from different sources and the other is social bonding between the sender and the receiver. We tested the efficiency of cross-checking and social bonding in a laboratory experiment where subjects played the Prisoner's Dilemma with gossip interactions. Although individuals ha...
Humans are capable of solving cooperation problems following social norms. Social norms dictate a... more Humans are capable of solving cooperation problems following social norms. Social norms dictate appropriate behaviour and judgement on others in response to their previous actions and reputation. Recently, the so-called leading eight norms have been identified from many potential social norms that can sustain cooperation through a reputation-based indirect reciprocity mechanism. Despite indirect reciprocity being claimed to extend direct reciprocity in larger populations where direct experiences cannot be accumulated, the success of social norms have been analysed in models with global information and evolution. This study is the first to analyse the leading eight norms with local information and evolution. We find that the leading eight are robust against selfish players within most scenarios and can maintain a high level of cooperation also with local information and evolution. In fact, local evolution sustains cooperation under a wider set of conditions than global evolution, whi...
High school track choice determines college access in many countries. We hypothesize that some qu... more High school track choice determines college access in many countries. We hypothesize that some qualified students avoid the college-bound track in high school simply because they overestimate admission requirements. To test this hypothesis, we conducted a randomized field experiment that communicated the admission standards of local secondary schools on the academic track to students in Hungary before the application deadline. We targeted the subset of students (“seeds”) who occupied the most central position in the classroom-social networks, aiming to detect both direct effects on the track choice of targeted seeds and spillover effects on their untreated peers. We found neither a direct effect nor a spillover effect on students’ applications or admissions on average. Further analyses, however, revealed theoretically plausible heterogeneity in the direct causal effect of the intervention on the track choice of targeted seeds. Providing information about admission standards increase...
Journal of Artificial Societies and Social Simulation, 2019
Traditional desegregation policies have improved but not fully solved the problems associated wit... more Traditional desegregation policies have improved but not fully solved the problems associated with the reproduction of inequalities and interracial prejudice in schools. This is partly because social networks are inherently segregated within integrated schools and the benefits of contact have not fully materialized. Therefore, new kinds of policies are needed to further improve the situation. This paper investigates the consequences and e iciency of seating arrangements on academic outcomes and prejudice using an agent-based model that reflects real-life asymmetries. We model interpersonal dynamics and study behavior in the classroom in the hypothetical case of a single teacher who defines students' seating arrangements. The model incorporates the mechanisms of peer influence on study behavior, on attitude formation, and homophilous selection in order to depict the interrelated dynamics of networks, behavior, and attitudes. We compare various seating arrangement scenarios and observe how GPA distribution and level of prejudice changes over time. Results highlight the advantages and disadvantages of seating strategies. In general, more heterogeneous deskmate pairs lead to a lower level of inequality and prejudice in the classroom, but this strategy does not favor talent management. Further, we evaluate outcomes compared to the absence of external intervention whereby students choose their own deskmates based on homophilous selection. Our model takes into account the fact that homophilous selection may be distorted due to the 'Acting White' phenomenon and pre-existing prejudice. Accounting for these factors implies slower convergence between advantaged and disadvantaged students.
How and why animals and humans signal reliably is a key issue in biology and social sciences. For... more How and why animals and humans signal reliably is a key issue in biology and social sciences. For many years the dominant paradigm in biology was the Handicap Principle. It claims a causal relationship between honesty and signal cost and thus predicts that honest signals have to be costly to produce. However, contrary to the Handicap Principle, game theoretical models predict that honest signaling is maintained by condition dependent signaling trade-offs and honest signals need not be costly at the equilibrium. Due to the difficulties of manipulating signal cost and signal trade-offs there is surprisingly little evidence to test these predictions either from biology or from social sciences. Here we conduct a human laboratory experiment with a two-factorial design to test the role of equilibrium signal cost vs. signalling trade-offs in the maintenance of honest communication. We have found that the trade-off condition has much higher influence on the reliability of communication than...
1 tudományos segédmunkatárs, mTa Társadalomtudományi Kutatóközpont "lendület" rECENS Kutatócsopor... more 1 tudományos segédmunkatárs, mTa Társadalomtudományi Kutatóközpont "lendület" rECENS Kutatócsoport 2 tudományos segédmunkatárs, mTa Társadalomtudományi Kutatóközpont "lendület" rECENS Kutatócsoport 3 kutató, mTa Társadalomtudományi Kutatóközpont "lendület" rECENS Kutatócsoport 4 tudományos segédmunkatárs, mTa Társadalomtudományi Kutatóközpont "lendület" rECENS Kutatócsoport, egyetemi tanársegéd, Szegedi Tudományegyetem Bölcsészettudományi Kar orosz Filológiai Tanszék 5 PhD, az mTa Társadalomtudományi Kutatóközpont "lendület" rECENS Kutatócsoport vezetője
Our study contributes to the debate on the evolution of cooperation in the singleshot Prisoner's ... more Our study contributes to the debate on the evolution of cooperation in the singleshot Prisoner's Dilemma (PD) played on networks. We construct a model in which individuals are connected with positive and negative ties. Some agents play signdependent strategies that use the sign of the relation as a shorthand for determining appropriate action toward the opponent. In the context of our model in which network topology, agent strategic types and relational signs coevolve, the presence of signdependent strategies catalyzes the evolution of cooperation. We highlight how the success of cooperation depends on a crucial aspect of implementation: whether we apply parallel or sequential strategy update. Parallel updating, with averaging of payoffs across interactions in the social neighborhood, supports cooperation in a much wider set of parameter values than sequential updating. Our results cast doubts about the realism and generalizability of models that claim to explain the evolution of cooperation but implicitly assume parallel updating.
Previous research describes social structure in which employees are embedded as one of the import... more Previous research describes social structure in which employees are embedded as one of the important determinants of intra-organizational career expectations. There are two contradictory arguments in the literature, however. First, social closure of informal relations is supposed to strengthen the intentions of staying. Second, the efficiency and effectivity of the individual social network is assumed to enhance in-house career expectations. This empirical study analyzed data from 44 R&D teams in the Netherlands. Multilevel analysis was used to separate individual and team influences. Results show that the prospects to stay in the R&D team are determined positively by social closure, whereas the expectation to stay in the organization is determined positively by the efficiency and effectivity of individual social networks. The conclusions highlight that different forms of social capital might be important for different types of career perspectives.
Dense in-group and scarce out-group relations (network segregation) often support the emergence o... more Dense in-group and scarce out-group relations (network segregation) often support the emergence of conflicts between groups. A key underlying mechanism is social control that helps to overcome the collective action problem within groups, but contributes to harmful conflicts among them in segregated settings. In this study, a new experimental design is introduced to test whether internalized social control affects contribution decisions in intergroup-related collective action. Subjects played single-shot Intergroup Public Good games in two groups of five each without communication. Subjects were connected via computers and connection patterns were manipulated to detect forms of social control that are activated conditional on expectations and on the composition of the artificially created ego-network. Results confirm the influence of behavioral confirmation and the conditional impact of internalized traitor and selective incentives. As an aggregated consequence of these social control effects, harmful intergroup outcomes were least likely when members of the groups were arranged in a mixed network.
The evolution of unconditional cooperation is one of the fundamental problems in science. A new s... more The evolution of unconditional cooperation is one of the fundamental problems in science. A new solution is proposed to solve this puzzle. We treat this issue with an evolutionary model in which agents play the Prisoner's Dilemma on signed networks. The topology is allowed to co-evolve with relational signs as well as with agent strategies. We introduce a strategy that is conditional on the emotional content embedded in network signs. We show that this strategy acts as a catalyst and creates favorable conditions for the spread of unconditional cooperation. In line with the literature, we found evidence that the evolution of cooperation most likely occurs in networks with relatively high chances of rewiring and with low likelihood of strategy adoption. While a low likelihood of rewiring enhances cooperation, a very high likelihood seems to limit its diffusion. Furthermore, unlike in non-signed networks, cooperation becomes more prevalent in denser topologies.
Physica A: Statistical Mechanics and its Applications, 2007
Previous models of collective action assume that the network structure of individual relations th... more Previous models of collective action assume that the network structure of individual relations that transmit social control mechanisms promoting or inhibiting collective action is given. An extended game-theoretical model that incorporates social control mechanisms as side payments and allows for endogenous network change is presented here. The model represents collective action as a public goods game and predicts that network clustering undermines mass public good production and the possibility of deleting ties leads towards equilibrium structures in which contributors and defectors are segregated. It is argued and elaborated how laboratory experiments with virtual social networks can be used to test these model predictions. An innovative experimental method is proposed, in which subjects are seated behind computers that are connected according to simple network structures. Subjects are informed about the decisions of their contacts and could send happy or sad smiley symbols to them, which are two possible operationalizations of social control mechanisms. In addition, subjects could delete existing links in reaction to collective action outcomes or to avoid unpleasant forms of social control. Results of a larger series of experimental tests are to follow.
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