Reasoning about evidence

Bayesians understand the notion of evidential support in terms of probability raising. Little is known about the logic of the evidential support relation, thus understood. We investigate a number of prima facie plausible candidate logical principles for the evidential support relation and show which of these principles the Bayesian evidential support relation does and which it does not obey. We also consider the question which of these principles hold for a stronger notion of evidential support.     

Waiting When Both Certainty and Magnitude Are Increasing: Certainty Overshadows Magnitude

In everyday decision making, people often face decisions with outcomes that differ on multiple dimensions. The trade‐off in preferences between magnitude, temporal proximity, and probability of an outcome is a fundamental concern in the decision‐making literature. Yet, their joint effects on behavior in an experience‐based decision‐making task are understudied. Two experiments examined the relative influences of the magnitude and probability of an outcome when both were increasing over a 10‐second delay. A first‐person shooter video game was adapted for this purpose. Experiment 1 showed that participants waited longer to ensure a higher probability of the outcome than to ensure a greater magnitude when experienced separately and together. Experiment 2 provided a precise method of comparing their relative control on waiting by having each increase at different rates. Both experiments revealed a stronger influence of increasing probability than increasing magnitude. The results were more consistent with hyperbolic discounting of probability than with cumulative prospect theory's decision weight function. Copyright © 2014 John Wiley & Sons, Ltd.     

Control your cravings: Self-controlled food choice varies by eating attitudes,sex, and food type among Division I collegiate athletes

Eating attitudes are predictive of disordered eating, which can be quite prevalent among collegiate athletes. The present study tested if disordered eating attitudes and the sex of collegiate athletes are related to “self-controlled food choice” for four food types: a dessert, fried food, fruit, and vegetable. In total, 102 athletes completed a disordered eating attitudes assessment and a delay discounting task. For the delay discounting task, athletes chose between one large delayed reward and one successively smaller immediate reward for four food types, and indifference points were computed with lower indifference points indicating greater self-controlled food choice. In this study female athletes showed greater self-controlled food choice for all three tempting food types (dessert, fried food, and fruit), but not the control food type (vegetable). For males, results were moderated by their level of disordered eating attitudes. Overall, these data show that “self-controlled food choice,” measured using a delay discounting task, is a key factor related to sex differences in disordered eating attitudes among college athletes.     

The Accuracy of Causal Learning Over Long Timeframes: An Ecological Momentary Experiment Approach

The ability to learn cause–effect relations from experience is critical for humans to behave adaptively — to choose causes that bring about desired effects. However, traditional experiments on experience-based learning involve events that are artificially compressed in time so that all learning occurs over the course of minutes. These paradigms therefore exclusively rely upon working memory. In contrast, in real-world situations we need to be able to learn cause–effect relations over days and weeks, which necessitates long-term memory. 413 participants completed a smartphone study, which compared learning a cause–effect relation one trial per day for 24 days versus the traditional paradigm of 24 trials back- to- back. Surprisingly, we found few differences between the short versus long timeframes. Subjects were able to accurately detect generative and preventive causal relations, and they exhibited illusory correlations in both the short and long timeframe tasks. These results provide initial evidence that experience-based learning over long timeframes exhibits similar strengths and weaknesses as in short timeframes. However, learning over long timeframes may become more impaired with more complex tasks.     

Hazard function effects on promoting self-control in variable interval time-based interventions in rats

The present experiments investigated properties of time-based interventions used to increase self-control. Rats received impulsive-choice assessments before and after interventions that consisted of different distributions of delays to reinforcement. In Experiment 1, rats received an intervention with an increasing hazard function where delays were more evenly distributed, a decreasing hazard function where delays were mostly short, or a constant hazard function where delays were exponentially distributed. Surprisingly, rats that received the decreasing hazard function made the most self-controlled choices. Response rates during intervention trials showed that rats anticipated reinforcement based on the shape of the distributions they received. In Experiment 2, rats received an intervention with a decreasing hazard function with a steep slope or a shallow slope. Both time-based interventions increased self-control and produced similar response-rate patterns, indicating that the slope of the decreasing hazard function may not play a strong role in intervention efficacy. While this research aligns with previous literature showing that time-based interventions improved self-control, exposure to short delays produced the biggest improvements. Ultimately, exposure to short delays may increase the subjective value of the larger–later choice while occasional long delays may promote the ability to wait, which may have important implications for translational applications.     

Intuitive Probabilities and the Limitation of Moral Imagination

There is a vast literature that seeks to uncover features underlying moral judgment by eliciting reactions to hypothetical scenarios such as trolley problems. These thought experiments assume that participants accept the outcomes stipulated in the scenarios. Across seven studies (N = 968), we demonstrate that intuition overrides stipulated outcomes even when participants are explicitly told that an action will result in a particular outcome. Participants instead substitute their own estimates of the probability of outcomes for stipulated outcomes, and these probability estimates in turn influence moral judgments. Our findings demonstrate that intuitive likelihoods are one critical factor in moral judgment, one that is not suspended even in moral dilemmas that explicitly stipulate outcomes. Features thought to underlie moral reasoning, such as intention, may operate, in part, by affecting the intuitive likelihood of outcomes, and, problematically, moral differences between scenarios may be confounded with non‐moral intuitive probabilities.     

Prospective emotion enables episodic prospection to shift time preference

The episodic effect suggests that episodic prospection (imagining future events) can effectively reduce time discounting, the propensity to discount the value of delayed rewards relative to immediate ones. However, less clear is how episodic prospection modulates time preference. As engagement in episodic prospection usually evokes prospective emotions, it was proposed that episodic prospection might work by inducing prospective emotions. Although one previous study has attempted to provide evidence to the emotional account of the episodic effect, shortcomings in its experimental design make its conclusion questionable. In this study, we replicated previous experimental design with improvements to further test the effects of prospective emotion on time preference. By manipulating the emotional valency associated with episodic prospection in a delay discounting task, we found that positive episodic prospection attenuated time discounting; negative episodic prospection exacerbated time discounting; and episodic prospection did not shift time preference when prospective emotion is removed. These results were essentially identical to the result of the previous study. Together, these studies suggested that the effects of episodic prospection depended on prospective emotion. Thus, one cannot ignore prospective emotion if counting on episodic prospection to combat humans’ impulsive behaviours.     

Effects of immediacy of feedback on estimations and performance

We investigated the role of anticipation of feedback in performance and estimation about own performance. We submitted 155 participants to a test of verbal aptitude, and we requested them to give estimations of their own performance and the performance of other participants. There were two treatments: immediate feedback and delayed feedback. Participants in the immediate‐feedback group were informed that they would receive feedback on their performance immediately after finishing the test, whereas participants in the delayed‐feedback group were informed that they would receive feedback a week after taking the test. The immediate‐feedback group performed better than the delayed‐feedback group. Furthermore, the former underestimated their own performance. On the other hand, participants on the delayed‐feedback group made unbiased estimations. We present a mathematical model based on construal‐level theory, decision affect theory, temporal discounting, and Moore and Healy's model of overestimation. The model suggests that the source of differences in performance and in estimations of own performance is a construal of the feedback situation that modifies the expected utility of the task.