The influence of caloric information on cafeteria food choices

We evaluated the effect of posting caloric information on food purchases at a cafeteria. Purchases of more than 14,300 entrees, vegetables, and salads by 6,970 customers were unobtrusively monitored via the cash register inventory control system during 15 evening observations. A quasi-multiple-baseline design across food groups was used to test the additive effect of labeling the three lowest caloric choices for vegetables, salads, and entrees. A linear logit analysis confirmed that labeling increased the probability of low calorie selections for vegetables and salads, but not for entrees. Observations of meals purchased by a subsample of 413 customers indicated labeling did not change the total caloric content of meals. The number of customers and total sales per evening were unaffected by the labeling intervention. The results suggest that manipulating environmental cues may be an effective method for changing food purchases in a cafeteria, but labeling individual items may not be the best way to decrease total calories purchased.     

Evaluations of Outcome Sequences

We extend the literature on intertemporal choice by investigating how possession of knowledge related to the present value of future outcomes (PV knowledge) affects the extent to which individuals weight certain attributes when evaluating outcome sequences. While PV-knowledgeable individuals can ascribe value to attributes according to their PV relevance (or irrelevance), unknowledgeable individuals cannot do so. Such knowledge, therefore, likely interacts with outcome-sequence attributes to affect the extent to which individuals exhibit impatience when evaluating outcome sequences. The main experimental findings indicate that higher PV knowledge increases the extent to which individuals value impatience (as opposed to improvement). However, these findings also reinforce a need to distinguish among impatience, improvement, and PV because some higher PV knowledge participants willingly sacrifice PV while exhibiting impatience (while others do so in order to gain improvement). Overall, PV considerations appear central, but not determinative, in higher PV-knowledgeable individuals' evaluations of outcome sequences.     

Building blocks of self-control: increased tolerance for delay with bundled rewards

Impulsive choice can be defined as temporary preference for a smaller-sooner reward (SS) over a larger-later reward (LL). Hyperbolic discounting implies that impulsive choices will occur less when organisms choose between a series of SSs versus LLs all at once than when they choose between single SS versus LL pairs. Eight rats were exposed to two conditions of an intertemporal choice paradigm using sucrose solution as reward. In both conditions, the LL was 150 microl delayed by 3 s, while the SS was an immediate reward that ranged from 25-150 microl across sessions. Preference for the LL was greater when the chosen reward was automatically delivered three times in succession (bundled) than when it was chosen singly and delivered after each choice. For each of the 8 rats, the estimated SS amount that produced indifference was higher in the bundled condition than in the single condition. Because bundling in humans may be based on the perception that one's current choice is predictive of future choices, the data presented here may demonstrate an important building block of self-control.     

跨期决策中的维度差异偏好：眼动证据

在跨期决策研究领域,虽然基于维度的跨期模型得到了一些源自结果检验和过程检验的证据支持,但此类模型所假设的维度间差异比较的心理过程尚缺乏直接的过程证据。本研究通过两个眼动实验,系统考察了相关眼动指标对维度差异偏好的预测效应。结果发现,根据基于维度的权衡模型可有效拟合出个体在跨期决策中的维度差异偏好,并且反应时、眼跳注视熵和静态注视熵等指标均与维度差异偏好负相关,而基于维度的注意分配与维度差异判断正相关。这些研究发现支持了本研究所提出的跨期眼动模型的相关假设,证实了维度差异偏好与跨期决策的认知加工过程之间的联系,为基于维度的跨期模型提供了更直接的过程证据,并为今后跨期决策的眼动模型发展指明了新方向。     

Group choice: the ideal free distribution of human social behavior

Group choice refers to the distribution of group members between two choice alternatives over time. The ideal free distribution (IFD), an optimal foraging model from behavioral ecology, predicts that the ratio of foragers at two resource sites should equal the ratio of obtained resources, a prediction that is formally analogous to the matching law of individual choice, except that group choice is a social phenomenon. Two experiments investigated the usefulness of IFD analyses of human group choice and individual-based explanations that might account for the group-level events. Instead of nonhuman animals foraging at two sites for resources, a group of humans chose blue and red cards to receive points that could earn cash prizes. The groups chose blue and red cards in ratios in positive relation to the ratios of points associated with the cards. When group choice ratios and point ratios were plotted on logarithmic coordinates and fitted with regression lines, the slopes (i.e., sensitivity measures) approached 1.0 but tended to fall short of it (i.e., undermatching), with little bias and little unaccounted for variance. These experiments demonstrate that an IFD analysis of group choice is possible and useful, and suggest that group choice may be explained by the individual members' tendency to optimize reinforcement.     

风险对两类跨期选择的影响：一项ERP研究

该研究利用ERP技术,采用伴随风险的跨期选择任务比较了两类跨期选择（立即vs.延迟、延迟vs.延迟）,并探究了风险（零风险、低风险、高风险）对两者跨期选择影响的神经动力学机制。ERP结果显示,对于立即vs.延迟和延迟vs.延迟,在N2和N400上前者大于后者,在LPC上后者大于前者;风险对两者在时程上的影响趋于一致。因此,其加工可能是先对奖赏在风险维度上进行折扣,再与延迟时间进行整合形成奖赏预期,而后做出选择。     

The predictive accuracy of intertemporal‐choice models

How do people choose between a smaller reward available sooner and a larger reward available later? Past research has evaluated models of intertemporal choice by measuring goodness of fit or identifying which decision‐making anomalies they can accommodate. An alternative criterion for model quality, which is partly antithetical to these standard criteria, is predictive accuracy. We used cross‐validation to examine how well 10 models of intertemporal choice could predict behaviour in a 100‐trial binary‐decision task. Many models achieved the apparent ceiling of 85% accuracy, even with smaller training sets. When noise was added to the training set, however, a simple logistic‐regression model we call the difference model performed particularly well. In many situations, between‐model differences in predictive accuracy may be small, contrary to long‐standing controversy over the modelling question in research on intertemporal choice, but the simplicity and robustness of the difference model recommend it to future use.     

Patterns and evolution of moral behaviour: moral dynamics in everyday life

Recent research on moral dynamics (the processes and phenomena – collective or individual – by which moral behaviour and moral attitudes emerge, evolve, spread, erode or disappear) shows that an individual's ethical mind-set (i.e. outcome-based vs. rule-based) moderates the impact of an initial ethical or unethical act on the likelihood of behaving ethically on a subsequent occasion. More specifically, an outcome-based mind-set facilitates Moral Balancing (behaving ethically or unethically decreases the likelihood of engaging in the same type of behaviour again later), whereas a rule-based mind-set facilitates Moral Consistency (engaging in an ethical or unethical behaviour increases the likelihood of engaging in the same type of behaviour later on). The objective was to look at the evolution of moral choice across a series of scenarios, that is, to explore if these moral patterns (Balancing vs. Consistency) are maintained over time. The results of three studies showed that Moral Balancing is not maintained over time. On the other hand, Moral Consistency could be maintained over time, if the mind-set was reinforced before making a new moral judgment (but not otherwise).     

得失不对称：跨期选择中自我-他人决策差异

采用跨期选择任务范式,考察得失情境下自我–他人决策差异。结果发现：（1）为自己决策比为他人决策更偏好于选择即刻选项;（2）损失情境比获益情境下更偏好于选择即刻选项;（3）获益情境下为自己决策与为他人决策在选择即刻选项上不存在显著差异,而损失情境下为自己决策比为他人决策更偏好于选择即刻选项,表明得失情境下自我–他人决策差异存在不对称性。