Jolie M. Martin

Intergroup prisoner's dilemma with Intragroup Power Dynamics

The Intergroup Prisoner’s Dilemma with Intragroup Power Dynamics (IPD^2) is a new game paradigm for studying human behavior in conflict situations. IPD^2 adds the concept of intragroup power to an intergroup version of the standard Repeated Prisoner’s Dilemma game. We conducted a laboratory study in which individual human participants played the game against computer strategies of various complexities. The results show that participants tend to cooperate more when they have greater power status within their groups. IPD^2 yields increasing levels of mutual cooperation and decreasing levels of mutual defection, in contrast to a variant of Intergroup Prisoner’s Dilemma without intragroup power dynamics where mutual cooperation and mutual defection are equally likely. We developed a cognitive model of human decision making in this game inspired by the Instance-Based Learning Theory (IBLT) and implemented within the ACT-R cognitive architecture. This model was run in place of a human participant using the same paradigm as the human study. The results from the model show a pattern of behavior similar to that of human data. We conclude with a discussion of the ways in which the IPD^2 paradigm can be applied to studying human behavior in conflict situations. In particular, we present the current study as a possible contribution to corroborating the conjecture that democracy reduces the risk of wars.

A Cognitive Model of Dynamic Cooperation With Varied Interdependency Information

We analyze the dynamics of repeated interaction of two players in the Prisoners Dilemma (PD) under various levels of interdependency information and propose an instance-based learning cognitive model (IBL-PD) to explain how cooperation emerges over time. Six hypotheses are tested regarding how a player accounts for an opponents outcomes: the selfish hypothesis suggests ignoring information about the opponent and utilizing only the players own outcomes; the extreme fairness hypothesis weighs the players own and the opponents outcomes equally; the moderate fairness hypothesis weighs the opponents outcomes less than the players own outcomes to various extents; the linear increasing hypothesis increasingly weighs the opponents outcomes at a constant rate with repeated interactions; the hyperbolic discounting hypothesis increasingly and nonlinearly weighs the opponents outcomes over time; and the dynamic expectations hypothesis dynamically adjusts the weight a player gives to the opponents outcomes, according to the gap between the expected and the actual outcomes in each interaction. When players lack explicit feedback about their opponents choices and outcomes, results are consistent with the selfish hypothesis; however, when this information is made explicit, the best predictions result from the dynamic expectations hypothesis.

Practice makes improvement: how adults with autism out-perform others in a naturalistic visual search task.

People with autism spectrum disorder (ASD) often exhibit superior performance in visual search compared to others. However, most studies demonstrating this advantage have employed simple, uncluttered images with fully visible targets. We compare the performance of high-functioning adults with ASD and matched controls on a naturalistic luggage screening task. Although the two groups were equally accurate in detecting targets, the ASD adults improve in their correct elimination of target-absent bags faster than controls. This feature of their behavior is extremely important for many real-world monitoring tasks that require sustained attention for long time periods. Further analyses suggest that this improvement is attributable neither to the motor speed nor to the level of intelligence of the adults with ASD. These findings may have possible implications for employment opportunities of adult individuals with ASD.

The effects of individual and context on aggression in repeated social interaction

In two studies using variations of the Prisoners Dilemma game, we explore the combined impact of individual traits and social context on aggressive behavior. In the first study, we compared defection rates in the Iterated Prisoners Dilemma when participants were presented with a payoff matrix (Description condition) or learned payoffs through experience (Experience condition). Interpersonal trust and maximizing tendency led to relatively more cooperation in the Description condition than in the Experience condition, demonstrating that individual characteristics manifest differently depending on the information available to decision-makers. In the second study, we employed a new game paradigm, the Intergroup Prisoners Dilemma with Intragroup Power Dynamics, to examine the way that power motives influence extreme aggressive behavior. We discovered that certain individuals exhibit very high levels of defection, but only when they play with particular combinations of predefined strategies, suggesting further how the confluence of individual factors and context can induce aggression.

The effects of individual and context on aggression in repeated social interaction.

In two studies using variations of the Prisoners Dilemma game, we explore the impact of individual traits and social context on aggressive behavior. In the first study, we compared defection rates in the Iterated Prisoners Dilemma when participants were presented with a payoff matrix (Description condition) or learned payoffs through experience (Experience condition). Interpersonal trust and maximizing tendency led to relatively less defection in the Description condition than in the Experience condition, demonstrating that individual characteristics manifest differently depending on the information available to decision-makers. In the second study, we employed a new game paradigm, the Intergroup Prisoners Dilemma with Intragroup Power Dynamics, to examine the way that power motives influence extreme aggressive behavior. We discovered that certain individuals exhibit very high levels of defection, but only when they play with particular combinations of predefined strategies, further suggesting how the confluence of individual factors and context can induce aggression.

Cognitive aspects of power in a two-level game

The Intergroup Prisoners Dilemma with Intragroup Power Dynamics (IPD∧2) is a new game paradigm for studying human behavior in conflict situations. IPD∧2 adds the concept of intragroup power to an intergroup version of the standard Iterated Prisoners Dilemma game. We conducted an exploratory laboratory study in which individual human participants played the game against computer strategies of various complexities. We also developed a cognitive model of human decision making in this game. The model was run in place of the human participant under the same conditions as in the laboratory study. Results from the human study and the model simulations are presented and discussed, emphasizing the value of including intragroup power in game theoretic models of conflict.