Good things come to those who wait: Time discounting differences between adult offenders and nonoffenders

Criminal behavior has been explained by the idea that offenders have a lack of self-control. Yet, Wilson and Daly reported that juvenile offenders exhibit time-discounting tendencies similar to those of nonoffending juveniles. As no previous study has compared time-discounting behavior of adult offenders with nonoffenders, we raise the question, do adult offenders exhibit shorter time horizons or the tendency to discount future rewards? To answer this question, 89 offenders (ex-prisoners and prisoners) and 106 nonoffenders completed a time-discounting measure containing 27 different monetary choices. Our results show that, counter to findings with juvenile offenders, adult offenders (ex-prisoners) exhibit significantly shorter time horizons and discount more than nonoffenders as delayed payoffs increase to medium and large rewards. Furthermore, both offenders and nonoffenders are less likely to discount as the reward of future gains increases to medium and large.     

American base‐rate neglect: It is not the math,but the context

We investigate cross‐cultural disparities in focalism bias through two studies of probability estimation. Using 60 American and 60 Chinese participants, Experiment 1 yields the standard finding that Americans manifest greater focalism bias by tending to neglect background probability base‐rates and to rely more heavily on obtained samples in estimating true probabilities, whereas Chinese participants show little tendency to ignore base‐rates. In Experiment 2, the phrasing of the probability‐estimation task is changed to bring base‐rates into the focus of the problem statement, again using a sample of 60 Americans and 60 Chinese. This allows us to test whether cross‐cultural differences result from a tendency to focus on the sample, and ignore ‘context’ (i.e., the background base‐rates), rather than simply a discrepancy in mathematical facility between the two groups. The results show far less base‐rate neglect for Americans, but essentially no change for Chinese (who always use base‐rate information, regardless of how presented). This outcome argues against the explanation that Americans are poorer Bayesians simply because they are weaker mathematicians. Implications are discussed.     

Individual differences in impulsive choice and timing in rats

Individual differences in impulsive choice behavior have been linked to a variety of behavioral problems including substance abuse, smoking, gambling, and poor financial decision-making. Given the potential importance of individual differences in impulsive choice as a predictor of behavioral problems, the present study sought to measure the extent of individual differences in a normal sample of hooded Lister rats. Three experiments utilized variations of a delay discounting task to measure the degree of variation in impulsive choice behavior across individual rats. The individual differences accounted for 22-55% of the variance in choice behavior across the three experiments. In Experiments 2 and 3, the individual differences were still apparent when behavior was measured across multiple choice points. Large individual differences in the rate of responding, and modest individual differences in timing of responding were also observed during occasional peak trials. The individual differences in timing and rate, however, did not correlate consistently with individual differences in choice behavior. This suggests that a variety of factors may affect choice behavior, response rate, and response timing.     

Protecting Against Low‐Probability Disasters: The Role of Worry

We carry out a large monetary stakes insurance experiment with very small probabilities of losses and ambiguous as well as exact probabilities. Many individuals do not want to pay anything for insurance whether the probabilities are given exactly or are ambiguous. Many others, however, are willing to pay surprisingly large amounts. With ambiguity, the percentage of those paying nothing is smaller and the willingness to pay (WTP) of the other individuals larger than with exact probabilities. Comparing elasticities with ambiguity, we find that worry is much more important than subjective probability in determining WTP for insurance. Furthermore, when the ambiguous loss probability is increased by a factor of 1000, it has almost no effect on WTP. Copyright © 2011 John Wiley & Sons, Ltd.     

Disjunction Between Probability and Verdict in Juror Decision Making

Although the law assumes a close relation between the probability that a defendant committed the act in question and the ensuing verdict of the jurors, prior research has shown this assumption to be often violated. We present five experiments designed to show that factors that influence probability also influence verdict, but other factors are capable of directly producing changes in verdict without affecting probability. In Experiment 1, we replicated the Wells Effect; scenarios generating the same probability that the Blue Bus Company was to blame for the same accident, nevertheless, generated significantly different likelihoods of finding the defendant liable. In Experiment 2, we showed that equally diagnostic affirmative and negative evidence had differential effects on mock jurors' probability estimates and verdicts. In Experiment 3, we showed that a completely nondiagnostic witness, who either implicates the same bus company or a different bus company as did a diagnostic witness, significantly influenced mock jurors' verdicts. However, the nondiagnostic witness did not change the probability that the Blue Bus Company was responsible for the accident. In Experiment 4, we demonstrated that base rate and witness reliability information resulted in very similar probability estimates but radically different verdicts. In Experiment 5, we showed that a change in the diagnosticity of the evidence influenced both probability and verdict with the former mediating differences in the later. Because probability is only one of the several determinants of the verdict, the two dependent variables are not as closely related as the law presumes. Copyright © 2011 John Wiley & Sons, Ltd.     

Instance‐based Learning: A General Model of Repeated Binary Choice

A common practice in cognitive modeling is to develop new models specific to each particular task. We question this approach and draw on an existing theory, instance‐based learning theory (IBLT), to explain learning behavior in three different choice tasks. The same instance‐based learning model generalizes accurately to choices in a repeated binary choice task, in a probability learning task, and in a repeated binary choice task within a changing environment. We assert that, although the three tasks are different, the source of learning is equivalent and therefore, the cognitive process elicited should be captured by one single model. This evidence supports previous findings that instance‐based learning is a robust learning process that is triggered in a wide range of tasks from the simple repeated choice tasks to the most dynamic decision making tasks. Copyright © 2010 John Wiley & Sons, Ltd.     

Feelings of dread and intertemporal choice

It frequently has been observed that people discount future rewards relative to present rewards. However, the literature on intertemporal choices involving emotional upsets and losses is fraught with inconsistencies, with some studies finding similar discounting of gains and losses, and others reporting that participants elect to undergo negative experiences sooner rather than later. To help resolve these contradictions, time preferences for different types of aversive experiences (social rejection, embarrassment, pain, monetary and property loss) were examined in five studies. Most participants preferred to postpone monetary and property losses, but intertemporal choices for other unpleasant experiences showed highly variable responses, with some participants deferring them as long as possible, and many electing to experience them immediately. Time preferences for these negative experiences were correlated, but were independent of time preference for rewards. It is argued (following Loewenstein, 1987 ) that anticipation of dread plays a key role in many people's choices about timing of aversive experiences. This interpretation was supported by choices about when to learn of a very unpleasant event whose timing was fixed (Study 3), and by a novel preference reversal (Study 4). Study 5 examined how actual and hypothetical experiences of dread unfolded over time; the results were consistent with a dread‐based interpretation of choices in the preceding studies. Copyright © 2010 John Wiley & Sons, Ltd.     

How fast can you (possibly) do it,or how long will it (certainly) take? Communicating uncertain estimates of performance time

Recent research on verbal probability statements has revealed that some expressions (e.g., possible) are especially appropriate for describing outcomes in the high end of a distribution, whereas other expressions (e.g., certain) are more appropriate for describing low-end values. However, some dimensions appear to be reversible, with higher achievements sometimes associated with high and sometimes with low values, depending on frame. We report three experiments where this “reframing effect” is studied in communications of estimated performance time, both from a speaker's and from a listener's perspective. We hypothesize that statements describing tasks as “taking time” suggest a duration frame, and find accordingly that statements about how many hours that possibly will be spent on a task, or the time a task possibly takes, lead to high time estimates. Statements focusing on the actor's role suggest, in contrast, a speed frame, thus statements about what the actor can possibly do lead to low time estimates. Estimates of the time a task certainly takes or when it is certainly done follow the opposite pattern. The results are in line with approaches that see production and comprehension of language as a dynamical and context-driven process.     

Weighing Outcomes by Time or Against Time? Evaluation Rules in Intertemporal Choice

Models of intertemporal choice draw on three evaluation rules, which we compare in the restricted domain of choices between smaller sooner and larger later monetary outcomes. The hyperbolic discounting model proposes an alternative‐based rule, in which options are evaluated separately. The interval discounting model proposes a hybrid rule, in which the outcomes are evaluated separately, but the delays to those outcomes are evaluated in comparison with one another. The tradeoff model proposes an attribute‐based rule, in which both outcomes and delays are evaluated in comparison with one another: People consider both the intervals between the outcomes and the compensations received or paid over those intervals. We compare highly general parametric functional forms of these models by means of a Bayesian analysis, a method of analysis not previously used in intertemporal choice. We find that the hyperbolic discounting model is outperformed by the interval discounting model, which, in turn, is outperformed by the tradeoff model. Our cognitive modeling is among the first to offer quantitative evidence against the conventional view that people make intertemporal choices by discounting the value of future outcomes, and in favor of the view that they directly compare options along the time and outcome attributes.