Cooperation declines in repeated public good games because individuals behave as conditional coop... more Cooperation declines in repeated public good games because individuals behave as conditional cooperators. This is because individuals imitate the social behaviour of successful individuals when their payoff information is available. However, in human societies, individuals cooperate in many situations involving social dilemmas. We hypothesize that humans are sensitive to both success (payoffs) and how that success was obtained, by cheating (not socially sanctioned) or good behaviour (socially sanctioned and adds to prestige or reputation), when information is available about payoffs and prestige. We propose and model a repeated public good game with heterogeneous conditional cooperators where an agent's donation in a public goods game depends on comparing the number of donations in the population in the previous round and with the agent's arbitrary chosen conditional cooperative criterion. Such individuals imitate the social behaviour of role models based on their payoffs an...
It has been known that altruistic punishments solve the free rider problem in public goods games.... more It has been known that altruistic punishments solve the free rider problem in public goods games. Considering spatial structure and considering pure strategies significant advances have been made in understanding the evolution of altruistic punishments. However, these models have not considered key behavior regularities observed in experimental and field settings, where the individuals behave like conditional cooperators who are more willing to donate and are also more willing to punish free riders. Considering these behavioral regularities, without imposing a spatial structure on the population, I propose an evolutionary agent-based model in which agents behave like conditional cooperators, each agent's donation conditional on the difference between the number of donations in the past and the threshold value and the propensity value of the agent. Altruistic punishment depends on the difference between the threshold value of the focal agent and the randomly matched another agent. The simulations show that, for certain inflicted costs of punishments, generous altruistic punishments evolve and stabilize cooperation. The results show that, unlike previous models, it is not necessary to punish all free riders equally; it is necessary to do so in the case of the selfish free riders but not in the case of negative reciprocators.
The co-evolution of conditional cooperation and social norms has garnered significant attention, ... more The co-evolution of conditional cooperation and social norms has garnered significant attention, yet the underlying mechanisms remain elusive. Social norms result from empirical expectations, individual expectations of group behavior, and normative expectations, the population's expectations of individual behavior. Aligning these expectations aids in norm formation, but diverse individual reactions to observed behavior and their sensitivity to norm conformity can be challenging. In our study, the agents are initially endowed with diverse conditional expectations, which mirror their anticipations regarding group behavior and their inherent inclination to conform to social norms, indicative of their sensitivity to psychic costs. These agents engage in a repeated public goods game, where their decisions to cooperate are shaped by their conditional expectations and the observed levels of cooperation within their group. Concurrently, free riders experience psychic costs determined by...
The emergence of large language models has led to the development of powerful tools such as ChatG... more The emergence of large language models has led to the development of powerful tools such as ChatGPT that can produce text indistinguishable from human-generated work. With the increasing accessibility of such technology, students across the globe may utilize it to help with their school work-a possibility that has sparked discussions on the integrity of student evaluations in the age of artificial intelligence (AI). To date, it is unclear how such tools perform compared to students on university-level courses. Further, students' perspectives regarding the use of such tools, and educators' perspectives on treating their use as plagiarism, remain unknown. Here, we compare the performance of ChatGPT against students on 32 university-level courses. We also assess the degree to which its use can be detected by two classifiers designed specifically for this purpose. Additionally, we conduct a survey across five countries, as well as a more in-depth survey at the authors' institution, to discern students' and educators' perceptions of ChatGPT's use. We find that ChatGPT's performance is comparable, if not superior, to that of students in many courses. Moreover, current AI-text classifiers cannot reliably detect ChatGPT's use in school work, due to their propensity to classify human-written answers as AI-generated, as well as the ease with which AI-generated text can be edited to evade detection. Finally, we find an emerging consensus among students to use the tool, and among educators to treat this as plagiarism. Our findings offer insights that could guide policy discussions addressing the integration of AI into educational frameworks.
A fundamental question in social and biological sciences is whether self-governance is possible w... more A fundamental question in social and biological sciences is whether self-governance is possible when individual and collective interests are in conflict. Free riding poses a major challenge to self-governance, and a prominent solution to this challenge has been altruistic punishment. However, this solution is ineffective when counter-punishments are possible and when social interactions are noisy. We set out to address these shortcomings, motivated by the fact that most people behave like conditional cooperators—individuals willing to cooperate if a critical number of others do so. In our evolutionary model, the population contains heterogeneous conditional cooperators whose decisions depend on past cooperation levels. The population plays a repeated public goods game in a moderately noisy environment where individuals can occasionally commit mistakes in their cooperative decisions and in their imitation of the role models’ strategies. We show that, under moderate levels of noise, i...
It is observed that in a repeated public good game with same individuals, free riding by a few in... more It is observed that in a repeated public good game with same individuals, free riding by a few individuals in the initial rounds triggers free riding by others in the subsequent rounds. It is presumed that individuals tend to imitate social behaviour of successful or relatively high payoff individuals, irrespective of how the payoffs were obtained. However, humans are concerned about how the payoffs were obtained, such as whether the payoffs were obtained by cheating or good behaviour. Individuals are willing to incur certain cost in order to improve group benefits and these individuals gain prestige. In human societies individuals tend to imitate social behaviour of high prestige agents. We propose that when agents are aware of other agents' payoffs scores and their prestige, perhaps agents are more likely to imitate social behaviour of high prestige and high payoff agents. We introduce, population level affinity parameters such as affinity towards payoff and affinity towards p...
Marchiori and Warglien (2008 , Science, 319(5866), 1111–1113) showed that a simple regret-driven ... more Marchiori and Warglien (2008 , Science, 319(5866), 1111–1113) showed that a simple regret-driven neural network model outperforms almost all competing models when predicting human choice behaviour in games with ‘unique equilibrium in mixed strategies’. Considering its effectiveness in this class of games, we scale up the model to account for strategically more important decision-making scenarios like prisoners’ dilemma (PD). The modification is based on the assumption that the trajectory of behaviour observed in a repeated PD experiment is the result of the bidirectional attraction between pareto-optimal (mutual cooperation) versus self-interested defection (mutual defection) in repeated PD game. The simulation results significantly capture the qualitative trends in behaviour over time.
Pictorial space is the 3-D impression that one obtains when looking `into' a 2-D picture. One... more Pictorial space is the 3-D impression that one obtains when looking `into' a 2-D picture. One is aware of 3-D `opaque' objects. `Pictorial reliefs' are the surfaces of such pictorial objects in `pictorial space'. Photographs (or any pictures) do in no way fully specify physical scenes. Rather, any photograph is compatible with an infinite number of possible scenes that may be called `metameric scenes'. If pictorial relief is one of these metameric scenes, the response may be considered `veridical'. The conventional usage is more restrictive and is indeed inconsistent. Thus the observer has much freedom in arriving at such a `veridical' response. To address this ambiguity, we determined the pictorial reliefs for eight observers, six pictures, and two psychophysical methods. We used `methods of cross-sections' to operationalise pictorial reliefs. We find that linear regression of the depths of relief at corresponding locations in the picture for differe...
Although altruistic punishments solve the free rider problem in repeated public good games, it ha... more Although altruistic punishments solve the free rider problem in repeated public good games, it has been a puzzle why altruistic punishers willing to incur personal costs in order to improve the group benefits. It has been shown that when the population consists of a finite set of pure strategies along with altruistic punishers, altruistic punishments evolve in the population. These models the population consists of a finite set of strategies and the strategies do not depend on the past strategies of the population. Unlike assumptions made in these models, the population is heterogeneous in their conditional cooperative strategies and the individuals who are more willing to donate also are more willing to punish the free riders. I propose an evolutionary agent-based model, each agent’s donation depends on the difference between the number of donations in the past and the threshold value and a propensity value. Altruistic punishment depends on the difference between the threshold valu...
Cooperation declines in repeated public good games because individuals behave as conditional coop... more Cooperation declines in repeated public good games because individuals behave as conditional cooperators. This is because individuals imitate the social behaviour of successful individuals when their payoff information is available. However, in human societies, individuals cooperate in many situations involving social dilemmas. We hypothesize that humans are sensitive to both success (payoffs) and how that success was obtained, by cheating (not socially sanctioned) or good behaviour (socially sanctioned and adds to prestige or reputation), when information is available about payoffs and prestige. We propose and model a repeated public good game with heterogeneous conditional cooperators where an agent's donation in a public goods game depends on comparing the number of donations in the population in the previous round and with the agent's arbitrary chosen conditional cooperative criterion. Such individuals imitate the social behaviour of role models based on their payoffs an...
Conditional cooperation declines over time if heterogeneous ideal conditional agents are involved... more Conditional cooperation declines over time if heterogeneous ideal conditional agents are involved in repeated interactions. With strict assumptions of rationality and a population consisting of ideal conditional agents who strictly follow a decision rule, cooperation is not expected. However, cooperation is commonly observed in human societies. Hence, we propose a novel evolutionary agent-based model where agents rely on social information. Each agent interacts only once either as a donor or as a receiver. In our model, the population consists of either non-ideal or ideal heterogeneous conditional agents. Their donation decisions are stochastically based on the comparison between the number of donations in the group and their conditional cooperative criterion value. Non-ideal agents occasionally cooperate even if the conditional rule of the agent is not satisfied. The stochastic decision and selection rules are controlled with decision intensity and selection intensity, respectively...
Pictorial space is the 3-D impression that one obtains when looking ‘into’ a 2-D picture. One is ... more Pictorial space is the 3-D impression that one obtains when looking ‘into’ a 2-D picture. One is aware of 3-D ‘opaque’ objects. ‘Pictorial reliefs’ are the surfaces of such pictorial objects in ‘pictorial space’. Photographs (or any pictures) do in no way fully specify physical scenes. Rather, any photograph is compatible with an infinite number of possible scenes that may be called ‘metameric scenes’. If pictorial relief is one of these metameric scenes, the response may be considered ‘veridical’. The conventional usage is more restrictive and is indeed inconsistent. Thus the observer has much freedom in arriving at such a ‘veridical’ response. To address this ambiguity, we determined the pictorial reliefs for eight observers, six pictures, and two psychophysical methods. We used ‘methods of cross-sections’ to operationalise pictorial reliefs. We find that linear regression of the depths of relief at corresponding locations in the picture for different observers often lead to very low (even insignificant) R2s. Thus the responses are idiosyncratic to a large degree. Perhaps surprisingly, we also observed that multiple regression of depth and picture coordinates at corresponding locations often lead to very high R2s. Often R2s increased from insignificant up to almost 1. Apparently, to a large extent ‘depth’ is irrelevant as a psychophysical variable, in the sense that it does not uniquely account for the relation of the response to the pictorial structure. This clearly runs counter to the bulk of the literature on pictorial ‘depth perception’. The invariant core of interindividual perception proves to be of an ‘affine’ rather than a Euclidean nature; that is to say, ‘pictorial space’ is not simply the picture plane augmented with a depth dimension.
Cooperation declines in repeated public good games because individuals behave as conditional coop... more Cooperation declines in repeated public good games because individuals behave as conditional cooperators. This is because individuals imitate the social behaviour of successful individuals when their payoff information is available. However, in human societies, individuals cooperate in many situations involving social dilemmas. We hypothesize that humans are sensitive to both success (payoffs) and how that success was obtained, by cheating (not socially sanctioned) or good behaviour (socially sanctioned and adds to prestige or reputation), when information is available about payoffs and prestige. We propose and model a repeated public good game with heterogeneous conditional cooperators where an agent's donation in a public goods game depends on comparing the number of donations in the population in the previous round and with the agent's arbitrary chosen conditional cooperative criterion. Such individuals imitate the social behaviour of role models based on their payoffs an...
It has been known that altruistic punishments solve the free rider problem in public goods games.... more It has been known that altruistic punishments solve the free rider problem in public goods games. Considering spatial structure and considering pure strategies significant advances have been made in understanding the evolution of altruistic punishments. However, these models have not considered key behavior regularities observed in experimental and field settings, where the individuals behave like conditional cooperators who are more willing to donate and are also more willing to punish free riders. Considering these behavioral regularities, without imposing a spatial structure on the population, I propose an evolutionary agent-based model in which agents behave like conditional cooperators, each agent's donation conditional on the difference between the number of donations in the past and the threshold value and the propensity value of the agent. Altruistic punishment depends on the difference between the threshold value of the focal agent and the randomly matched another agent. The simulations show that, for certain inflicted costs of punishments, generous altruistic punishments evolve and stabilize cooperation. The results show that, unlike previous models, it is not necessary to punish all free riders equally; it is necessary to do so in the case of the selfish free riders but not in the case of negative reciprocators.
The co-evolution of conditional cooperation and social norms has garnered significant attention, ... more The co-evolution of conditional cooperation and social norms has garnered significant attention, yet the underlying mechanisms remain elusive. Social norms result from empirical expectations, individual expectations of group behavior, and normative expectations, the population's expectations of individual behavior. Aligning these expectations aids in norm formation, but diverse individual reactions to observed behavior and their sensitivity to norm conformity can be challenging. In our study, the agents are initially endowed with diverse conditional expectations, which mirror their anticipations regarding group behavior and their inherent inclination to conform to social norms, indicative of their sensitivity to psychic costs. These agents engage in a repeated public goods game, where their decisions to cooperate are shaped by their conditional expectations and the observed levels of cooperation within their group. Concurrently, free riders experience psychic costs determined by...
The emergence of large language models has led to the development of powerful tools such as ChatG... more The emergence of large language models has led to the development of powerful tools such as ChatGPT that can produce text indistinguishable from human-generated work. With the increasing accessibility of such technology, students across the globe may utilize it to help with their school work-a possibility that has sparked discussions on the integrity of student evaluations in the age of artificial intelligence (AI). To date, it is unclear how such tools perform compared to students on university-level courses. Further, students' perspectives regarding the use of such tools, and educators' perspectives on treating their use as plagiarism, remain unknown. Here, we compare the performance of ChatGPT against students on 32 university-level courses. We also assess the degree to which its use can be detected by two classifiers designed specifically for this purpose. Additionally, we conduct a survey across five countries, as well as a more in-depth survey at the authors' institution, to discern students' and educators' perceptions of ChatGPT's use. We find that ChatGPT's performance is comparable, if not superior, to that of students in many courses. Moreover, current AI-text classifiers cannot reliably detect ChatGPT's use in school work, due to their propensity to classify human-written answers as AI-generated, as well as the ease with which AI-generated text can be edited to evade detection. Finally, we find an emerging consensus among students to use the tool, and among educators to treat this as plagiarism. Our findings offer insights that could guide policy discussions addressing the integration of AI into educational frameworks.
A fundamental question in social and biological sciences is whether self-governance is possible w... more A fundamental question in social and biological sciences is whether self-governance is possible when individual and collective interests are in conflict. Free riding poses a major challenge to self-governance, and a prominent solution to this challenge has been altruistic punishment. However, this solution is ineffective when counter-punishments are possible and when social interactions are noisy. We set out to address these shortcomings, motivated by the fact that most people behave like conditional cooperators—individuals willing to cooperate if a critical number of others do so. In our evolutionary model, the population contains heterogeneous conditional cooperators whose decisions depend on past cooperation levels. The population plays a repeated public goods game in a moderately noisy environment where individuals can occasionally commit mistakes in their cooperative decisions and in their imitation of the role models’ strategies. We show that, under moderate levels of noise, i...
It is observed that in a repeated public good game with same individuals, free riding by a few in... more It is observed that in a repeated public good game with same individuals, free riding by a few individuals in the initial rounds triggers free riding by others in the subsequent rounds. It is presumed that individuals tend to imitate social behaviour of successful or relatively high payoff individuals, irrespective of how the payoffs were obtained. However, humans are concerned about how the payoffs were obtained, such as whether the payoffs were obtained by cheating or good behaviour. Individuals are willing to incur certain cost in order to improve group benefits and these individuals gain prestige. In human societies individuals tend to imitate social behaviour of high prestige agents. We propose that when agents are aware of other agents' payoffs scores and their prestige, perhaps agents are more likely to imitate social behaviour of high prestige and high payoff agents. We introduce, population level affinity parameters such as affinity towards payoff and affinity towards p...
Marchiori and Warglien (2008 , Science, 319(5866), 1111–1113) showed that a simple regret-driven ... more Marchiori and Warglien (2008 , Science, 319(5866), 1111–1113) showed that a simple regret-driven neural network model outperforms almost all competing models when predicting human choice behaviour in games with ‘unique equilibrium in mixed strategies’. Considering its effectiveness in this class of games, we scale up the model to account for strategically more important decision-making scenarios like prisoners’ dilemma (PD). The modification is based on the assumption that the trajectory of behaviour observed in a repeated PD experiment is the result of the bidirectional attraction between pareto-optimal (mutual cooperation) versus self-interested defection (mutual defection) in repeated PD game. The simulation results significantly capture the qualitative trends in behaviour over time.
Pictorial space is the 3-D impression that one obtains when looking `into' a 2-D picture. One... more Pictorial space is the 3-D impression that one obtains when looking `into' a 2-D picture. One is aware of 3-D `opaque' objects. `Pictorial reliefs' are the surfaces of such pictorial objects in `pictorial space'. Photographs (or any pictures) do in no way fully specify physical scenes. Rather, any photograph is compatible with an infinite number of possible scenes that may be called `metameric scenes'. If pictorial relief is one of these metameric scenes, the response may be considered `veridical'. The conventional usage is more restrictive and is indeed inconsistent. Thus the observer has much freedom in arriving at such a `veridical' response. To address this ambiguity, we determined the pictorial reliefs for eight observers, six pictures, and two psychophysical methods. We used `methods of cross-sections' to operationalise pictorial reliefs. We find that linear regression of the depths of relief at corresponding locations in the picture for differe...
Although altruistic punishments solve the free rider problem in repeated public good games, it ha... more Although altruistic punishments solve the free rider problem in repeated public good games, it has been a puzzle why altruistic punishers willing to incur personal costs in order to improve the group benefits. It has been shown that when the population consists of a finite set of pure strategies along with altruistic punishers, altruistic punishments evolve in the population. These models the population consists of a finite set of strategies and the strategies do not depend on the past strategies of the population. Unlike assumptions made in these models, the population is heterogeneous in their conditional cooperative strategies and the individuals who are more willing to donate also are more willing to punish the free riders. I propose an evolutionary agent-based model, each agent’s donation depends on the difference between the number of donations in the past and the threshold value and a propensity value. Altruistic punishment depends on the difference between the threshold valu...
Cooperation declines in repeated public good games because individuals behave as conditional coop... more Cooperation declines in repeated public good games because individuals behave as conditional cooperators. This is because individuals imitate the social behaviour of successful individuals when their payoff information is available. However, in human societies, individuals cooperate in many situations involving social dilemmas. We hypothesize that humans are sensitive to both success (payoffs) and how that success was obtained, by cheating (not socially sanctioned) or good behaviour (socially sanctioned and adds to prestige or reputation), when information is available about payoffs and prestige. We propose and model a repeated public good game with heterogeneous conditional cooperators where an agent's donation in a public goods game depends on comparing the number of donations in the population in the previous round and with the agent's arbitrary chosen conditional cooperative criterion. Such individuals imitate the social behaviour of role models based on their payoffs an...
Conditional cooperation declines over time if heterogeneous ideal conditional agents are involved... more Conditional cooperation declines over time if heterogeneous ideal conditional agents are involved in repeated interactions. With strict assumptions of rationality and a population consisting of ideal conditional agents who strictly follow a decision rule, cooperation is not expected. However, cooperation is commonly observed in human societies. Hence, we propose a novel evolutionary agent-based model where agents rely on social information. Each agent interacts only once either as a donor or as a receiver. In our model, the population consists of either non-ideal or ideal heterogeneous conditional agents. Their donation decisions are stochastically based on the comparison between the number of donations in the group and their conditional cooperative criterion value. Non-ideal agents occasionally cooperate even if the conditional rule of the agent is not satisfied. The stochastic decision and selection rules are controlled with decision intensity and selection intensity, respectively...
Pictorial space is the 3-D impression that one obtains when looking ‘into’ a 2-D picture. One is ... more Pictorial space is the 3-D impression that one obtains when looking ‘into’ a 2-D picture. One is aware of 3-D ‘opaque’ objects. ‘Pictorial reliefs’ are the surfaces of such pictorial objects in ‘pictorial space’. Photographs (or any pictures) do in no way fully specify physical scenes. Rather, any photograph is compatible with an infinite number of possible scenes that may be called ‘metameric scenes’. If pictorial relief is one of these metameric scenes, the response may be considered ‘veridical’. The conventional usage is more restrictive and is indeed inconsistent. Thus the observer has much freedom in arriving at such a ‘veridical’ response. To address this ambiguity, we determined the pictorial reliefs for eight observers, six pictures, and two psychophysical methods. We used ‘methods of cross-sections’ to operationalise pictorial reliefs. We find that linear regression of the depths of relief at corresponding locations in the picture for different observers often lead to very low (even insignificant) R2s. Thus the responses are idiosyncratic to a large degree. Perhaps surprisingly, we also observed that multiple regression of depth and picture coordinates at corresponding locations often lead to very high R2s. Often R2s increased from insignificant up to almost 1. Apparently, to a large extent ‘depth’ is irrelevant as a psychophysical variable, in the sense that it does not uniquely account for the relation of the response to the pictorial structure. This clearly runs counter to the bulk of the literature on pictorial ‘depth perception’. The invariant core of interindividual perception proves to be of an ‘affine’ rather than a Euclidean nature; that is to say, ‘pictorial space’ is not simply the picture plane augmented with a depth dimension.
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