Individual differences in decision making: Drive and reward responsiveness affect strategic bargaining in economic games

BACKGROUND: In the growing body of literature on economic decision making, the main focus has typically been on explaining aggregate behavior, with little interest in individual differences despite considerable between-subject variability in decision responses. In this study, we were interested in asking to what degree individual differences in fundamental psychological processes can mediate economic decision-making behavior. METHODS: Specifically, we studied a personality dimension that may influence economic decision-making, the Behavioral Activation System, (BAS) which is composed of three components: Reward Responsiveness, Drive, and Fun Seeking. In order to assess economic decision making, we utilized two commonly-used tasks, the Ultimatum Game and Dictator Game. Individual differences in BAS were measured by completion of the BIS/BAS Scales, and correlations between the BAS scales and monetary offers made in the two tasks were computed. RESULTS: We found that higher scores on BAS Drive and on BAS Reward Responsiveness were associated with a pattern of higher offers on the Ultimatum Game, lower offers on the Dictator Game, and a correspondingly larger discrepancy between Ultimatum Game and Dictator Game offers. CONCLUSION: These findings are consistent with an interpretation that high scores on Drive and Reward Responsiveness are associated with a strategy that first seeks to maximize the likelihood of reward, and then to maximize the amount of reward. More generally, these results suggest that there are additional factors other than empathy, fairness and selfishness that contribute to strategic decision-making

Expectations in the Ultimatum Game: Distinct Effects of Mean and Variance of Expected Offers

Being treated fairly by others is an important need in everyday life. Experimentally, fairness can be studied using the Ultimatum Game, where the decision to reject a low, but non-zero offer is seen as a way to punish the other player for an unacceptable offer. The canonical explanation of such behavior is inequity aversion: people prefer equal outcomes over personal gains. However, there is abundant evidence that people's decision to reject a low offer can be changed by contextual factors and their emotional state, which cannot be explained by the inequity aversion model. Here, we expand a recent alternative explanation: rejections are driven by deviations from expectations: the larger the difference between the actual offer and the expected offer, the more likely one is to reject the offer. Specifically, we provided participants with explicit information on what kind of offers to expect using histograms depicting distribution of offers given in a previous experiment by the same proposers. Crucially, we showed four different distributions, manipulating both the mean and the variance of these expected sets of offers. We found that 50% of our participants clearly and systematically changed their behavior as a function of their expectations (11% followed the standard-economic model of pure self-interest and 39% where not distinguishable from the inequity-aversion model). Using a logistic mixed-model analysis, we found that the mean and variance differently affect the decision to reject an offer. Specifically, the mean expected offer affected the threshold of what offers are acceptable, while the expected variance of offers changed how strict participants were about this threshold. Together, these results suggest that social expectations have a more complex nature as current theories propose

Functional Imaging of Decision Conflict

Decision conflict occurs when people feel uncertain as to which option to choose from a set of similarly attractive (or unattractive) options, with many studies demonstrating that this conflict can lead to suboptimal decision making. In this article, we investigate the neurobiological underpinnings of decision conflict, in particular, the involvement of the anterior cingulate cortex (ACC). Previous studies have implicated the ACC in conflict monitoring during perceptual tasks, but there is considerable controversy as to whether the ACC actually indexes conflict related to choice, or merely conflict related to selection of competing motor responses. In a functional magnetic resonance imaging study, we dissociate the decision and response phases of a decision task, and show that the ACC does indeed index conflict at the decision stage. Furthermore, we sho that it does so for a complex decision task, one that requires the integration of beliefs and preferences and not just perceptual judgments

Catecholaminergic modulation of trust decisions

Rationale: Trust is a key component of social interactions. In order to assess the trustworthiness of others, people rely on both information learned from previous encounters, as well as on implicit biases associated with specific facial features. Objective: Here, we investigated the role of catecholamine (dopamine and noradrenaline) transmission on trust decisions as a function of both experienced behavior and facial features. Methods: To increase catecholamine levels, methylphenidate (MPH, i.e., Ritalin®, 20 mg) was administered to participants (N = 24) prior to their playing a well-studied economic task, namely the Trust Game (Berg et al. 1995). We measured the amount of money invested with a variety of game partners. Across game partners, we manipulated two aspects of trust: the facial trust level (high facial trust, low facial trust, and non-social) and the likelihood of reciprocation (high, low). Results: Results demonstrated no main effect of MPH on investments, but rather a selective lowering of investments under MPH as compared with placebo with the game partners who were low on facial trustworthiness and were low reciprocators. Conclusion: These results provide evidence that MPH administration impacts social trust decision-making, but does so in a context-specific manner

Social rank and social cooperation: Impact of social comparison processes on cooperative decision-making.

Successful navigation of our complex social world requires the capability to recognize and judge the relative status of others. Hence, social comparison processes are of great importance in our interactions, informing us of our relative standing and in turn potentially motivating our behavior. However, so far few studies have examined in detail how social comparison can influence interpersonal decision-making. One aspect of social decision-making that is of particular importance is cooperative behavior, and identifying means of maintaining and promoting cooperation in the provision of public goods is of vital interest to society. Here, we manipulated social comparison by grading performance rankings on a reaction time task, and then measured cooperative decisions via a modified Public Goods Game (PGG). Findings revealed that individuals ranked highest tended to be more cooperative as compared to those who placed in the bottom rank. Interestingly, this effect was regardless of whether the comparison group members were the subsequent players in the PGG or not, and this effect was stronger in those with higher social orientation. In summary, the present research shows how different social comparison processes (assessed via social rankings) can operate in our daily interaction with others, demonstrating an important effect on cooperative behavior

in press. Great expectations: neural computations underlying the use of social norms in decision-making

Social expectations play a critical role in everyday decision-making. However, their precise neuro-computational role in the decision process remains unknown. Here we adopt a decision neuroscience framework by combining methods and theories from psychology, economics and neuroscience to outline a novel, expectation-based, computational model of social preferences. Results demonstrate that this model outperforms the standard inequity-aversion model in explaining decision behavior in a social interactive bargaining task. This is supported by fMRI findings showing that the tracking of social expectation violations is processed by anterior cingulate cortex, extending previous computational conceptualizations of this region to the social domain. This study demonstrates the usefulness of this interdisciplinary approach in better characterizing the psychological processes that underlie social interactive decision-making

Screenshot, expectation induction.

<p>Introduction screen of a new partner in Study 2. The silhouette is coupled with an arbitrary ID number, a star rating, and written information about the participant’s past performance.</p