Cooperative Agent Systems: Artificial Agents Play the Ultimatum Game

We explore computational approaches for artificial agents to play the ultimatum game. We compare our agents\u27 behavior with that predicted by classical game theory, as well as behavior found in experimental (or behavioral) economics investigations. In particular, we study the following questions: How do artificial agents perform in playing the ultimatum game against fixed rules, dynamic rules, and rotating rules? How do coevolving artificial agents perform? Will learning software agents do better? What is the value of intelligence? What will happen when smart learning agents play against dumb (no-learning) agents? What will be the impact of agent memory size on performance? This exploratory study provides experimental results pertaining to these questions

The Role of Prosocial Behaviors in Mate Choice: a Critical Review of the Literature

Research has focused on the role of prosocial behaviors in mate choice, across both social and evolutionary psychology. Several studies provide strong support for the role of altruism in mate choice, whereby people find prosociality attractive in potential mates. As most research focuses on the role of altruism in mate choice, most research has found that people exhibit altruism towards attractive people, suggesting altruistic behavior is driven by mate choice motivation. Although studies have supported the notion that men’s altruism towards women is driven by mate choice, the findings are inconsistent, which may be due to the methodologies adopted by researchers. To our knowledge, this review paper is the first to critically review the literature concerning prosociality and mate choice. We provide an outline of the research thus far, methodological issues, and considerations for future research

Virtual world experimentation: an exploratory study

We explore the scientific potential of virtual worlds for experimental economics in terms of the subject pools and experimental platforms they present. Our results offer tentative, qualified support for virtual world experimentation. Overall, the be- haviour of virtual subjects recruited, incentivised and observed within Second Life across a range of five standard experimental games was not found to differ significantly from established standard results. In addition, we identify certain methodological opportunities and challenges which confront virtual world experimenters

Social decisions and fairness change when people’s interests are represented by autonomous agents

There has been growing interest on agents that represent people’s interests or act on their behalf such as automated negotiators, self-driving cars, or drones. Even though people will interact often with others via these agent representatives, little is known about whether people’s behavior changes when acting through these agents, when compared to direct interaction with others. Here we show that people’s decisions will change in important ways because of these agents; specifically, we showed that interacting via agents is likely to lead people to behave more fairly, when compared to direct interaction with others. We argue this occurs because programming an agent leads people to adopt a broader perspective, consider the other side’s position, and rely on social norms—such as fairness—to guide their decision making. To support this argument, we present four experiments: in Experiment 1 we show that people made fairer offers in the ultimatum and impunity games when interacting via agent representatives, when compared to direct interaction; in Experiment 2, participants were less likely to accept unfair offers in these games when agent representatives were involved; in Experiment 3, we show that the act of thinking about the decisions ahead of time—i.e., under the so-called “strategy method”—can also lead to increased fairness, even when no agents are involved; and, finally, in Experiment 4 we show that participants were less likely to reach an agreement with unfair counterparts in a negotiation setting. We discuss theoretical implications for our understanding of the nature of people’s social behavior with agent representatives, as well as practical implications for the design of agents that have the potential to increase fairness in society

Psychological and Neural Processing of Social Risk and Discrepancy in Major Depressive Disorder

Major Depressive Disorder (MDD) is one of the most prevalent health conditions in the world, characterised by persistent low mood and disruption to education, relationships, and employment. Disruption to social functioning is a core feature of MDD, and this dimension of the disorder may offer valuable insight into its aetiology. This thesis aims to extend our understanding of social processing in MDD by testing hypotheses generated from a socio-evolutionary theoretical framework of MDD, with particular emphasis on the Social Risk Hypothesis of Depressed Mood, which conceptualises depressed mood as an adaptive response to elevated risk of social exclusion. The thesis pursues these aims utilising novel protocols and neuroeconomic games to examine social risk-taking and self-discrepancies, and by examining the role of regions of the physical pain network in social function and processing of unexpected social information. The thesis consists of nine chapters; one general methodology chapter (Chapter 3), five chapters detailing novel experimental studies (Chapters 4,5,6,7 and 8), one describing a reanalysis of existing data (Chapter 2), one introductory chapter and one discussion chapter (Chapters 1 and 9 respectively). Across these chapters, the thesis presents neural and behavioural evidence that MDD is associated with reduced social risk-taking, increased sensitivity to an exclusion-relevant context (in-group interactions) and stronger enforcement of social norms. The thesis presents neural evidence of a negative processing bias for self-discrepancies in MDD, linked to activation in the dorsal anterior cingulate cortex and anterior insula, and suggesting a role for perfectionism as a transdiagnostic sensitivity to such discrepancies. Suggestions for future research are discussed, including increased utilisation of neuroeconomic games, particularly in relation to assessing social function as a transdiagnostic marker. Overall, the thesis provides support for socio-evolutionary frameworks of affect, and highlights their unique perspective for understanding affective disorders, with some ‘deficits’ usefully reconceptualised as adaptive mechanisms

Interpersonal Style Predicts Behavioral Heterogeneity During Economic-Exchange Task Gameplay in Individuals With Social Anxiety

Recent evidence suggests that individuals who exhibit socially anxious (SA) symptoms endorse patterns of maladaptive interpersonal behavior that can be parceled into three subtypes based upon interpersonal circumplex theory: friendly-submissive, hostile-submissive, and hostile-dominant. It remains unclear, however, whether these subtypes translate into observable social behavior in laboratory contexts. I used two economic-exchange tasks, the prisoner’s dilemma game (PDG) and the ultimatum game (UG), as models of domains of social behavior to detect interpersonal differences in a sample of college students (N= 88) who endorsed mild-to-severe levels of SA based upon responses to the Liebowitz Social Anxiety Scale Self-Report (LSAS-SR). Using a two-step automatic clustering procedure, the sample was divided into three groups according to their responses on the Inventory of Interpersonal Problems – 32 (IIP-32). Interpersonal profiles were constructed for these groups and two of the three expected subtypes were identified (friendly-submissive and hostile-submissive); however, instead of hostile-dominance, friendly-dominance emerged as a potential subtype. Hierarchical and quantile regressions were conducted to examine whether SA severity and interpersonal subtype predicted cooperation and acceptance rates in the PDG and UG respectively. The data revealed that in the PDG, SA severity significantly predicted an increase in cooperation rate, while the interpersonal subtypes did not have a significant effect. However, when analyses included only those individuals who met a clinical cutoff for severe SA (N = 66), SA severity no longer predicted cooperation rates. But friendly-submissiveness predicted cooperation rates exceeding 65% during gameplay, while friendly-dominance predicted a ceiling cooperation rate of 65%. Hostile-submissiveness did not predict variance in cooperation rate. In the UG, the interpersonal subtypes and SA severity did not significantly predict acceptance rate. These findings build upon a burgeoning literature substantiating links between self-reported interpersonal problems and unique interindividual psychopathological presentations. However, improvements in sample recruitment, the implementation of economic-exchange tasks, and data-analytic methods need to be put into practice before stronger assertions can be made concerning the therapeutic relevance of these games as social decision-making paradigms