更优更耐心：质量结果对跨期选择的影响

跨期选择以往的研究集中于金钱数量结果。基于维度加工的模型,本文探究了在跨期选择中,人们面对质量差异的结果(如,今天的低配版手机还是六个月后的高配版手机)vs.相对应的金钱结果(如,今天的5000元还是六个月后的6000元)的选择偏好差异。3个实验结果表明：人们面对质量结果(相比于金钱结果)的跨期选择表现得更耐心,而这种现象是由于人们面对选择时在结果维度差异感知不同所致。与金钱结果跨期选择相同,质量结果跨期选择的心理加工过程同样遵循维度间差异比较。本研究为基于维度的跨期选择模型提供了新的证据。     

心理距离对跨期选择和风险选择的影响

通过考察时间距离、社会距离和概率距离对跨期选择和风险选择的影响, 探究跨期选择和风险选择心理过程的相似性, 并检验不同心理距离影响决策的相似性。结果发现, 无论是时间距离(实验1)、社会距离(实验2)、还是概率距离(实验3), 心理距离越远, 被试在跨期选择中越倾向于延迟选项, 在风险选择中越倾向于风险选项。研究认为, 在跨期选择和风险选择中, 选项的表征结构和选项整体评价时不同选项特征的相对权重具有相似性。随着心理距离增加, 与高识解相联系的金额特征的相对权重增加, 与低识解相联系的时间和概率特征的相对权重降低, 这使得被试更倾向于选择金额较大的延迟和风险选项。同时, 研究发现三类心理距离对两类决策有相似影响, 进一步验证了不同心理距离的本质相似性。     

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。     

Too good to be true? Psychological responses to uncommon options in risk–reward environments

Risks and rewards, or payoffs and probabilities, are inversely related in many choice environments. We investigated people's psychological responses to uncommon combinations of risk and reward that deviate from learned regularities (e.g., options that offer a high payoff with an unusually high probability) as they evaluated risky options. In two experiments (N = 183), participants first priced monetary gambles drawn from environments in which risks and rewards were negatively correlated, positively correlated, or uncorrelated. In later trials, they evaluated gambles with uncommon combinations of risk and reward—that is, options that deviated from the respective environment's risk–reward structure. Pricing, response times, and (in Experiment 2) pupil dilation were recorded. In both experiments, participants took more time when responding to uncommon compared to foreseeable options or when the same options were presented in an uncorrelated risk–reward environment. This result was most pronounced when the uncommon gambles offered higher expected values compared to the other gambles in the set. Moreover, these uncommon, high‐value options were associated with an increase in pupil size. These results suggest that people's evaluations of risky options are based not only on the options' payoffs and probabilities but also on the extent to which they fit the risk–reward structure of the environment.     

The magnitude effect: Temporal discount rates and restaurant tips

Decision makers show a larger subjective temporal discount rate for small magnitudes than for large ones. That is, they demand a larger percent increase in value to compensate for a delay when they are waiting for a small amount of money than for a large amount. Prelec and Loewenstein (1991; see also Loewenstein & Prelec, 1992) proposed an increasing proportional sensitivity account of this magnitude effect. This account surmises that the magnitude effect stems from the utility function for money and is consequently not unique to intertemporal choice. One study tested this prediction by demonstrating the magnitude effect in two domains: intertemporal choice and tipping for restaurant meals, haircuts, and taxi rides. In intertemporal choice, subjects showed a larger discount rate for smaller monetary amounts. They also tipped a larger percentage on small bills than on large bills. Thus, both domains showed the magnitude effect; however, the size of the effect was not well correlated between domains.     

Tradeoffs in choice between risk and delay depend on monetary amounts

In Experiments 1 and 2, 25 and 48 college students made binary choices between hypothetical money amounts. In Part A, choices were between small amounts available with certainty and larger amounts ($10 to $10,000) available with risk. Choices in Part B were between immediate small amounts and delayed larger amounts. As money amount grew, risk aversion and delay aversion both changed but in opposite ways: Risk aversion grew but delay aversion shrank. Part C of Experiment 1 pitted risky amounts against delayed amounts, and its results were consistent with those of Parts A and B. Equivalences of particular risks and delays depended on the particular monetary amounts to which they attached. In Experiment 3, 20 college students made binary choices between money amounts, knowing that they would actually receive some of the selections they made. In Part A, choices were between certain small amounts and risky larger amounts ($1 and $10). Choice problems in Part B were between immediate small amounts and delayed receipt of $1 or $10. The results were like those of Experiment 1, though weaker. These results argue against models of choice that posit an equivalence of risk and delay that is independent of monetary amount.     

Differences in delay, not ratios, control choice in concurrent chains

In two experiments, pigeons were trained with concurrent-chains schedules, wherein responding to equal initial links measured preference between variable-interval terminal links. Absolute terminal-link duration was varied by keeping constant the difference between the terminal-link delays and forcing their ratio to change. Delay-reduction theory scales value relative to a common temporal context and requires that delay differences control choice. Thus, preference should remain invariant. Most competing accounts, including the matching law and a strong form of Weber's law, require that preference vary with the delay ratio. Experiment 1 employed standard concurrent chains, in which terminal-link position and color were confounded. Although average preference remained constant, individual preferences were highly variable and inconsistent, possibly due to carryover of position biases across conditions. In an attempt to reduce variability, Experiment 2 used a modified concurrent-chains procedure. Preference at different terminal-link durations was assessed simultaneously to prevent order effects, and terminal-link position was alternated randomly across trials to minimize the impact of position biases. In Experiment 2, both individual and mean preferences showed the constant-difference invariance. Overall, choice was controlled by terminal-link differences, not ratios.     

On the role of differential sample behaviors in matching-to-sample

Pigeons were trained on matching-to-sample (MTS) with differential sample-response requirements that were identical with respect to two pairs of sample stimuli but were either correlated or uncorrelated with correct choice. Experiment 1A showed that birds in the uncorrelated condition were slower to reach criterion levels of accuracy than birds in the correlated condition in spite of their equivalent sample discriminations. However, correlated birds were more disrupted in their matching performances than the uncorrelated birds when subsequently switched to nondifferential sample-response requirements (Experiment 1B). Experiment 2 showed that differential sample behaviors also generated higher levels of accuracy on delayed MTS when correlated with choice, and that accuracy in this condition did not differ as a function of whether the samples were hues or lines. Sample dimension did affect memory performance, on the other hand, in the uncorrelated condition. In Experiment 3, reversing differential sample-response requirements for one pair of samples substantially reduced matching accuracy in the correlated group but had almost no effect in the uncorrelated group. These findings demonstrate that differential sample behaviors directly control pigeons' matching performances and also overshadow conditional stimulus control by the samples when these behaviors are predictive of correct choice. The facilitation in matching produced by differential sample behaviors apparently arises from the additional cue these behaviors provide, not because they enhance sample discriminability.     

跨期选择单维占优模型的过程检验

跨期选择需要决策者在眼前与未来的损益之间做出权衡与取舍。主流跨期选择理论认为, 跨期选择是把未来价值折扣到现在, 根据折扣后的价值进行选择的过程; 而单维占优模型则认为决策者把“结果”维度上的差异和“延迟”维度上的差异进行比较(维度间差异比较), 然后根据差异更大的维度(即占优势的维度)进行决策。跨期选择众理论之争无果的原因之一或是研究者未能找到揭示其心理过程的令人信服的证据。为此, 本研究采用过程检验而非结果拟合的方法, 首创了“直观模拟天平”任务, 对维度间差异比较的大小进行测量, 从而为验证单维占优模型提供了支持性的证据。实验1A证明了维度间差异大小中介了选择结果, 被试认为“结果”维度上的差异相对于“延迟”维度上的差异越大, 越倾向于选择延迟长、结果大的选项; 反之, 被试认为“延迟”维度上的差异相对于“结果”维度上的差异越大, 越倾向于选择延迟短、结果小的选项。实验1B证明了维度间差异比较是在选择时实时(而不是在选择后)进行的。实验1C通过调整实验程序消减了共同方法偏差对结果的影响。实验2进一步证明维度间差异比较可以解释众多的跨期选择异象。通过4个实验, 本研究揭示了维度间差异比较构成了跨期选择的重要(尽管可能不是唯一)决策过程, 为支持单维占优模型提供了重要的过程验证证据。     

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.     

Risky choice as a function of amount and variance in food supply.

In Experiment 1, 4 rats earned their daily food ration by choosing on a trials basis between a "risky" and a "riskless" lever. The risky lever produced either 15 45-mg food pellets or no pellets, and on average provided five pellets per choice. The riskless lever always produced three pellets. Across conditions, the number of trials per session was varied. Body weight and choice of the risky lever decreased as the number of trials per session decreased, even though body weight could only be defended by increased choice of the risky lever. In Experiment 2, trials per session were fixed, but the number of pellets delivered by the risky and riskless levers was either at the same level as in Experiment 1 or tripled from those levels. Now choice of the risky lever was inversely related to the size of reinforcement and to body weight. The results of these experiments show that risk aversion covaries with the amount of food available in a session and the daily variance in the amount of food earned.     

Income and choice between different goods

In Experiment 1, 3 rats chose between two simultaneously operating variable-interval schedules, one of which provided saccharin water and the other, food. In five conditions, the absolute (and equal) reinforcement rates provided by the pair of equal-valued schedules were manipulated in the range of 36 to 240 per hour. Experiment 2 was identical to Experiment 1 except that these schedules operated successively, arranged by requiring the rat to stand on the side of the chamber correlated with each schedule. Food/saccharin choice ratios were inversely related to reinforcement rate in both experiments, although this effect was stronger in Experiment 2. When delivery rates were high, preference for food over saccharin often reversed as the session progressed. The results were interpretable in terms of economic accounts of choice (e.g., the minimum-needs hypothesis), as well as in terms of traditional psychological accounts (e.g., matching theory).     

Context effects on choice.

Four pigeons responded on a concurrent-chains schedule in four experiments that examined whether the effectiveness of a stimulus as a conditioned reinforcer is best described by a global approach, as measured by the average interreinforcement interval, or by a local contextual approach, as measured by the onset of the stimulus preceding the conditioned reinforcer. The interreinforcement interval was manipulated by the inclusion of an intertrial interval, which increased the overall time to reinforcement but did not change the local contingencies on a given trial A global analysis predicted choice for the richer alternative to decrease with the inclusion of an intertrial interval, whereas a local analysis predicted no change in preference. Experiment 1 examined sensitivity to intertrial intervals when each was signaled by the same houselight that operated throughout the session. In Experiment 2, the intertrial interval always was signaled by the stimulus correlated with the richer terminal link. In Experiment 3, the intertrial interval was signaled by the keylights correlated with the initial links and two novel houselights. Experiment 4 provided free food pseudorandomly during the intertrial interval. In all experiments, subjects' preferences were consistent with a local analysis of choice in concurrent chains. These results are discussed in terms of delay-reduction theory, which traditionally has failed to distinguish global and local contexts.     

“金钱-环境”复合收益的风险决策:价值取向的影响

现实中的环境决策,往往要在多个由"金钱-环境"复合而成的结果间做选择。人们如何对异质复合结果进行评估与选择,是决策研究面临的新课题。本研究着重考察个体金钱取向和环境取向的相对强度对复合收益风险决策的影响。结果表明,无论是采用自陈量表(实验1)或内隐联想测验(实验2)来测量价值取向,还是采用混词造句任务(实验3)来启动价值取向,均发现价值取向相对强度对复合风险决策有显著影响。(1)相比于金钱取向占优的个体,环境取向占优的个体在进行复合风险决策时更偏好环境风险较小的复合选项;(2)在复合选项等价匹配任务中,环境取向占优的个体会赋予复合选项中的环境收益以更高权重,倾向于用更多的金钱收益来弥补环境收益的风险折扣;(3)在复合收益风险概率匹配任务中,环境取向占优的个体更倾向于为获取倍增的环境收益而承担更大的复合收益风险。作为对复合结果风险决策的首次探索,本研究初步回答了不同价值取向的个体在金钱-环境复合风险决策中更倾向于规避什么风险、拿什么冒险以及为什么冒险等问题,为今后进一步开展复合决策研究打下了理论和方法基础。     

Money, Kisses, And Electric Shocks: On the Affective Psychology of Risk

Prospect theory's S-shaped weighting function is often said to reflect the psychophysics of chance. We propose an affective rather than psychophysical deconstruction of the weighting function resting on two assumptions. First, preferences depend on the affective reactions associated with potential outcomes of a risky choice. Second, even with monetary values controlled, some outcomes are relatively affect-rich and others relatively affect-poor. Although the psychophysical and affective approaches are complementary, the affective approach has one novel implication: Weighting functions will be more S-shaped for lotteries involving affect-rich than affect-poor outcomes. That is, people will be more sensitive to departures from impossibility and certainty but less sensitive to intermediate probability variations for affect-rich outcomes. We corroborated this prediction by observing probability-outcome interactions: An affect-poor prize was preferred over an affect-rich prize under certainty, but the direction of preference reversed under low probability. We suggest that the assumption of probability-outcome independence, adopted by both expected-utility and prospect theory, may hold across outcomes of different monetary values, but not different affective values.     

Temporal discounting for monetary and close relationship outcomes

The present study extended research on intertemporal choice—in which individuals choose between outcomes that may be received immediately or after a delay—to close relationships. In Experiment 1, New Zealand university students aged 18 to 25 made decisions about hypothetical monetary and relationship outcomes, and in Experiment 2, about relationship outcomes which emphasized companionate or sexual aspects (Ns = 64). Both experiments found effects of delay and magnitude on temporal discounting rates, and domain independence for choices about close relationships, similar to previous studies with monetary outcomes. There were no significant gender differences. Overall, results suggest that people make intertemporal choices about relationships according to a similar process used to make decisions involving other types of outcomes.     

Need for Cognition and Choice Framing Effects

Two experiments tested the hypothesis that framing biases in decision making would affect more strongly individuals with relatively low levels of need for cognition (NC). Participants were classified as high or low NC based on responses to a standard scale and subsequently were exposed to one of two framings of a choice problem. Different choice problems were used in each experiment, modeled after those developed by Kahneman and Tversky. Experiment 1 employed a monetary task and Experiment 2 a medical decision-making task. Consistent with expectations, framing effects on choice were observed in both experiments, but only for low NC participants. High NC participants were unaffected by problem framing, showing that they were less susceptible to attempts to alter their frame of reference.     

Zebrafish choice behavior is sensitive to reinforcer rate,immediacy, and magnitude ratios

Behavioral flexibility has, in part, been defined by choice behavior changing as a function of changes in reinforcer payoffs. We examined whether the generalized matching law quantitatively described changes in choice behavior in zebrafish when relative reinforcer rates, delays/immediacy, and magnitudes changed between two alternatives across conditions. Choice was sensitive to each of the three reinforcer properties. Sensitivity estimates to changes in relative reinforcer rates were greater when 2 variable-interval schedules were arranged independently between alternatives (Experiment 1a) than when a single schedule pseudorandomly arranged reinforcers between alternatives (Experiment 1b). Sensitivity estimates for changes in relative reinforcer immediacy (Experiment 2) and magnitude (Experiment 3) were similar but lower than estimates for reinforcer rates. These differences in sensitivity estimates are consistent with studies examining other species, suggesting flexibility in zebrafish choice behavior in the face of changes in payoff as described by the generalized matching law.     

Effects of self–other decision-making on time-based intertemporal choice

The effects of self–other decision-making on intertemporal choice have been revealed in many studies using a monetary outcome. However, the outcome of intertemporal choice is not restricted to money; time is also a scarce and nonrenewable resource outcome. Thus, we conducted a series of experiments to address the effects of self–other decision-making on time-based intertemporal choice, a type of intertemporal choice that uses time as an outcome. Over the course of three experiments, differences in self–other decision-making were evidenced. Participants who made decisions for others were more likely to prefer the smaller but sooner (SS) option over the larger but later (LL) option and considered the gain of the SS option to be significantly greater than that of the LL option. Participants who made decisions for themselves were likely to prefer the LL option over the SS option. However, they considered the gains of the LL and the SS option to be indifferent. Changing the role of decision-making could affect the ability of individuals to consider the future consequences of their decisions. The effects of self–other decision-making on time-based intertemporal choice could be explained by the accounts of economic reasoning and construal level theory. The findings indicated that the effects of self–other decision-making on time-based intertemporal choice, which could be generated simply by rewording questions, can help individuals make optimal long-term choices without the need for increased control.     

Instructions and reinforcement in the observing behavior of adults and children

Observing responses of college students and children of different ages (4 to 5, 9 to 10, and 13 to 14 years) were studied using two-component schedules of reinforcement. Different frequencies or numbers of points were given in the components and points were backed by either money or instructions about getting points (e.g., “points are for the experimenter's information only”). Stimuli that were either correlated or uncorrelated with the components were contingent on presses on either of two concurrently available levers (observing responses). In each of three experiments, preferences for stimuli were consistent with the conditioned-reinforcement hypothesis of observing but inconsistent with the uncertainty-reduction hypothesis. Stimulus preferences were established, eliminated, or reversed by instructions about the significance of getting points not backed with money. Instructions to in effect ignore points with no monetary value eliminated stimulus preference provided that money was not associated with points in other conditions for the same subjects. Stimulus preferences were otherwise independent of monetary point value. Instructions that described reinforcement contingencies promoted more rapid adjustment to the contingencies than occurred without them, and preferences were less variable across sessions within subjects and were on the average more extreme. Although some results involving absolute rates of observing depended upon the age of subjects, stimulus preferences did not. The data suggest that the conditioned-reinforcement hypothesis of observing has considerable generality for humans in choice procedures in the laboratory. That monetary value of points did not affect preferences in a graded fashion is consistent with versions of the conditioned-reinforcement hypothesis which emphasize reduction in delay to reinforcement over other reinforcement parameters.