From individual preference construction to group decisions: Framing effects and group processes

Two choice tasks known to produce framing effects in individual decisions were used to test group sensitivity to framing, relative to that of individuals, and to examine the effect of prior, individual consideration of a decision on group choice. Written post-decision reasons and pre-decision group discussions were analyzed to investigate process explanations of choices made by preexisting, naturalistic groups. For a risky choice problem, a similar framing effect was observed for groups and individuals. For an intertemporal choice task where consumption was either delayed or accelerated, naïve groups (whose members had not preconsidered the decision) showed a framing effect, less discounting in the delay frame, opposite to that observed in individuals. Predecided groups showed a non-significant effect in the other, expected direction. In all cases, process measures better explained variability in choices across conditions than frame alone. Implications for group decision research and design considerations for committee decisions are addressed.     

Group vs individual information processing: The effects of outcome feedback on decision making

Recent theories of individual decision making have emphasized the role of environmental feedback on decision performance and confidence. However, in relation to group decision making, feedback has received only minor attention. This study compared individual and group decision performance and confidence on a multicue personnel decision task under three different feedback conditions. Individuals and five-person groups decided whether to promote 48 different job candidates, and rated how confident they were in each of their decisions. Feedback as to the correctness of their decisions was provided after (a) every decision (Total Feedback), (b) only those decisions to promote the candidate (Partial Feedback), or (c) after none of the decisions (No Feedback). Results indicated that groups performed best under total feedback, while individuals performed best under partial feedback. In addition, greater amounts of feedback reduced individuals' confidence but had little effect on group member confidence. Implications for both current theory in decision making and group vs individual information processing are discussed.     

Performance and process in collective and individual memory: the role of social decision schemes and memory bias in collective memory

To assess performance and processes in collective and individual memory, participants watched two job candidates on video. Beforehand, half the participants were told they would be tested on their memory of the interviews, and the other half were asked to make a decision to hire one of the candidates. Afterwards, participants completed a recognition memory task in either a group or individual condition. Groups had better recognition memory than individuals. Individuals made more false positives than false negatives and groups exaggerated this. Post-hoc analysis found that groups only exaggerated the tendency towards false positives on items that reflected negatively on the job candidate. There was no significant difference between instruction conditions. When reaching consensus on the recognition task, groups tended to choose the correct answer if at least two members had the correct answer. This method of consensus is discussed as a factor in groups' superior memory performance.     

Temporal discounting of rewards in patients with bipolar disorder and schizophrenia

Patients with bipolar disorder (BD) and schizophrenia (SZ) often show decision-making deficits in everyday circumstances. A failure to appropriately weigh immediate versus future consequences of choices may contribute to these deficits. We used the delay discounting task in individuals with BD or SZ to investigate their temporal decision making. Twenty-two individuals with BD, 21 individuals with SZ, and 30 healthy individuals completed the delay discounting task along with neuropsychological measures of working memory and cognitive function. Both BD and SZ groups discounted delayed rewards more steeply than did the healthy group even after controlling for current substance use, age, gender, and employment. Hierarchical multiple regression analyses showed that discounting rate was associated with both diagnostic group and working memory or intelligence scores. In each group, working memory or intelligence scores negatively correlated with discounting rate. The results suggest that (a) both BD and SZ groups value smaller, immediate rewards more than larger, delayed rewards compared with the healthy group and (b) working memory or intelligence is related to temporal decision making in individuals with BD or SZ as well as in healthy individuals.     

个体自信度对双人决策的影响

群体决策是重要的社会现象, 个体自信度在群体决策中发挥了重要作用。本文开展了不同难度和信息交流方式下的双人决策实验, 通过分析自信度和个体决策以及决策调整行为的关系, 研究了个体自信度的交流对双人决策的影响。实验结果表明, 个体的自信度与选择的正确率高度正相关; 双人决策过程是个体根据对方的自信度和选择来不断调整自己的选择最终达成一致的过程, 并通过交互过程提高双人决策的正确率; 实验中双人决策的质量明显优于“自信度分享模型”和“更自信者主导决策模型”的预期结果, 表明群体决策不是通过分享自信度进行的贝叶斯优化整合过程, 也不是由更自信的个体完全主导的过程。     

Differences in the memory-based searching of delayed and normally developing young children

The memory-based searching of developmentally delayed and normal 2-year-old children was compared. The results of the study confirmed the hypothesis that individual differences would be minimal in a relatively noneffortful memory task, but that substantial individual differences would occur when more cognitive effort was required. The performance of the delayed and normal children was very good and quite similar in the basic memory task, which simply involved remembering the location of a toy hidden in a distinctive, natural location in a room. Substantial individual differences were found, however, in the children's ability to draw inferences about plausible locations for a missing toy based on their memory for where it had been hidden. When they discovered that their toy was not where they remembered it had been hidden (it had been surreptitiously moved by the experimenter), a group of normal children searched for the toy in places that were nearby or otherwise related to the original location of the toy. They used their memory for where the toy had been hidden to generate plausible alternative locations to search. In contrast, delayed children, who discovered their toy to be unaccountably missing from a location, persevered in repeatedly searching that same place. Unlike the normal children, they did not try something new. An important aspect of the data reported is that they reveal an important difference-not just a delay-in the cognitive functioning of young delayed children.     

The testing effect as a function of explicit testing instructions and judgments of learning

During study, people monitor their learning; the output of this monitoring is captured in so-called judgments of learning (JOLs). JOLs predict later recall better if they are made after a slight delay, instead of immediately after study (the delayed JOL effect). According to the self-fulfilling prophecy (SFP) hypothesis delayed JOLs are based on covert retrieval attempts from long-term memory, and successful retrieval attempts in themselves enhance learning (the testing effect). We compared memory for 40 Swahili-Swedish paired associates after a week as a function of three different learning conditions, namely study plus (i) explicitly instructed self-testing, (ii) delayed JOLs, or (iii) less self-testing. We showed that repeated delayed JOLs lead to a memory improvement that does not differ significantly from a comparable condition where the participants are explicitly testing memory, and both the latter groups performed reliably better than a group that self-tested less. The results suggest that delayed JOLs improve long-term retention as efficiently as explicit memory testing and lend support to the SFP hypothesis.     

Individual and group advice taking in judgmental forecasting: Is group forecasting superior to individual forecasting?

We examined how individuals and groups behave in making judgmental forecasts when they are given external forecast advice. We compare individual and group advice-taking behavior under different conditions: (a) when advice quality is fixed, (b) when advice quality is randomly varied, and (c) when there is feedback on advice quality or not. Participants in Study 1 received fixed advice of either reasonable or unreasonable quality while making their decisions. Participants in Study 2 randomly received both reasonable and unreasonable advice. We found in both studies that groups feel more confident than individuals. This greater confidence decreased the groups' reliance on advice. We also found that groups are better than individuals at discerning the quality of advice. In the group treatment, the group's reliance on advice increased according to the degree of disagreement with the initial decisions of the group members. In Study 3, participants randomly received both reasonable and unreasonable advice, and in addition, they received feedback on actual realizations that enabled them to learn about the quality of advice. In the presence of feedback on random advice quality, groups are no longer less receptive to advice than individuals; with feedback, both individuals and groups discount advice more than they do without feedback. Nevertheless, groups are still better than individuals at discerning the quality of advice. We conclude that group forecasting is better than individual forecasting across various conditions that we investigate except when advice quality is known to be consistently reliable.     

Context effects on group-based employee selection decisions

The decoy effect occurs when preferences between two alternatives reverse as a result of the manipulation of a third alternative (i.e., a decoy) such that it is dominated by only one of the two original alternatives. Previous research has demonstrated this effect in employee selection decisions, but only when decisions were made by individuals. The present investigation was designed to test the generalizability of the phenomenon to decisions made by groups, and to determine the influence of process and outcome accountability on the decoy effect. Results showed that the overall decoy effect held for both individual and group decisions. However, for both individuals and groups, the decoy effect held only when decision makers knew they would have to justify their decision processes.     

Groups, group members and individual decision processes: the effects of decision strategy, social interaction style and reception of decision-threatening information on post-decision processes

In two experiments, one conducted at an individual level and one at a group level, it was investigated how decision strategies and the reception of decision-threatening information affect the degree of post-decision consolidation for both individual and group decision-makers. In Experiment 1, roughly half the 55 participants made decisions in three-person groups and the other half individually. The type of decision strategies subjects employed (compensatory, non-compensatory, other) was assessed by questionnaire. In two post-decision sessions, consolidation was assessed using a memory task, either decision-supporting or decision-threatening information being provided at the start of the last post-decision session. In Experiment 2, the same design and procedure were used at a group level. In both experiments, the groups (and the single group members) were analyzed with the SYMLOG instrument. The results indicated that individual decision-makers consolidated their own decisions more than members of decision-making groups. There was also greater post-decision consolidation with the use of non-compensatory decision strategies as well as with reception of decision-threatening information, this latter result being seen as providing an explanation for the greater consolidation that individual decision-makers showed. Furthermore, single task-oriented group members and groups with a task-oriented leader consolidated the decision made by their group.     

Post-decision consolidation in large group decision-making

Decision-makers tend to change the psychological attractiveness of decision alternatives in favor of their own preferred alternative after the decision is made. In two experiments, the present research examined whether such decision consolidation occurs also among individual group members in a large group decision-making situation. High-school students were presented with a decision scenario on an important issue in their school. The final decision was made by in-group authority, out-group authority or by majority after a ballot voting. Results showed that individual members of large groups changed the attractiveness of their preferred alternative from a pre- to a post-decision phase, that these consolidation effects increased when decisions were made by in-group members, and when participants identified strongly with their school. Implications of the findings for understanding of group behavior and subgroup relations are discussed.     

Differential short-term memorisation for vocal and instrumental rhythms

This study explores differential processing of vocal and instrumental rhythms in short-term memory with three decision (same/different judgments) and one reproduction experiment. In the first experiment, memory performance declined for delayed versus immediate recall, with accuracy for the two rhythms being affected differently: Musicians performed better than non-musicians on clapstick but not on vocal rhythms, and musicians were better on vocal rhythms in the same than in the different condition. Results for the second experiment showed that concurrent sub-vocal articulation and finger-tapping differentially affected the two rhythms and same/different decisions, but produced no evidence for articulatory loop involvement in delayed decision tasks. In a third experiment, which tested rhythm reproduction, concurrent sub-vocal articulation decreased memory performance, with a stronger deleterious effect on the reproduction of vocal than of clapstick rhythms. This suggests that the articulatory loop may only be involved in delayed reproduction not in decision tasks. The fourth experiment tested whether differences between filled and empty rhythms (continuous vs. discontinuous sounds) can explain the different memorisation of vocal and clapstick rhythms. Though significant differences were found for empty and filled instrumental rhythms, the differences between vocal and clapstick can only be explained by considering additional voice specific features.     

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.     

Individual Versus Group Decision Making: Social Comparison in Goals for Individual Task Performance

This experiment compares the decisions of individuals and groups on goals for the performance expected from individuals on a problem-solving or an error-checking task. For both tasks, two versions were constructed to reflect low and high levels of task difficulty. Predictions from two different social comparison of abilities approaches were formulated, with the social comparison based on success approach predicting that group goals would be easier than individual goals, while social comparison based on performance predicted the opposite pattern. Consistent with the social comparison based on success predictions, group goals were observed to be significantly less difficult than individual goals for both tasks, both levels of task difficulty, and for both an initial and a second goal-setting occasion. Of particular interest was a finding that the easier group goals reflected group member preferences for easy goals in anticipation of group decision making. It is proposed that social factors such as evaluation apprehension and social comparison may be responsible for the differences observed in group and individual goal decisions, and that social factors may have an important role in a variety of goal-setting situations.     

Are intertemporal preferences contagious? Evidence from collaborative decision making

Prior research has provided substantial insight into individuals’ intertemporal preferences (i.e., preferences about delayed rewards). In the present study, we instead investigated the preferences of small groups of individuals asked to express collective intertemporal decisions. The paradigm consisted of three phases. During the precollaboration and postcollaboration phases, participants completed an intertemporal decision task individually. During the collaboration phase, participants completed a similar task in small groups, reaching mutually-agreed-upon decisions. The results suggest that group preferences were systematically related to the mean of the group members’ precollaboration preferences. In addition, collaborative decision making altered the group members’ intertemporal preferences. Specifically, individuals’ postcollaboration preferences converged toward the preferences of their respective groups. Furthermore, we found that individuals’ postcollaboration preferences were independently related to both their precollaboration preferences and the preferences of the other group members, suggesting that individuals’ postcollaboration preferences represented a revision of their precollaboration preferences based on the preferences observed in other group members. In Experiment 2, we demonstrated that similar patterns of results were found whether participants were making matching judgments or binary choices.     

Framing effects in group investment decision making: role of group polarization

Prospect theory proposes that framing effects result in a preference for risk-averse choices in gain situations and risk-seeking choices in loss situations. However, in group polarization situations, groups show a pronounced tendency to shift toward more extreme positions than those they initially held. Whether framing effects in group decision making are more prominent as a result of the group-polarization effect was examined. Purposive sampling of 120 college students (57 men, 63 women; M age = 20.1 yr., SD = 0.9) allowed assessment of relative preference between cautious and risky choices in individual and group decisions. Findings indicated that both group polarization and framing effects occur in investment decisions. More importantly, group decisions in a gain situation appear to be more cautious, i.e., risk averse, than individual decisions, whereas group decisions in the loss situation appear to be more risky than individual decisions. Thus, group decision making may expand framing effects when it comes to investment choices through group polarization.     

The effects of statistical training on choice heuristics in choice under uncertainty

Kahneman and Tversky (1984) proposed that decision makers perceive choice uncertainty in two ways: (1) as a distribution of possible outcomes or (2) as a single uncertain outcome. Using statistical training as a factor that influences these perceptions, and thus the type of decision approach individuals use, we found that individuals with different levels of experience displayed differences in the decisions they made and in the choice heuristics used to make those decisions. Statistically naive individuals were more likely to prefer loss-minimizing alternatives, use a more non-compensatory heuristic, and spend more time on loss-related information than their statistically experienced counterparts. When a distributional cue, indicating the distributional nature of choice outcomes, was presented to both experience groups, the naive group was found to use a decision approach similar to the experienced group and to make similar decisions. The results are discussed in terms of the need to include factors that alter individuals' approaches to uncertainty in future behavioral models of uncertain choice.     

Does delaying judgments of learning really improve the efficacy of study decisions? Not so much

A widely held assumption in metamemory is that better, more accurate metamemory monitoring leads to better, more efficacious restudy decisions, reflected in better memory performance--we refer to this causal chain as the restudy selectivity hypothesis. In 3 sets of experiments, we tested this hypothesis by factorially manipulating metamemory monitoring accuracy and self-regulation of study. To manipulate monitoring accuracy, we compared judgments of learning (JOLs) made contemporaneously with a delayed retrieval attempt to JOLs either made at a delay without attempting retrieval or made immediately after study; in previous studies, delayed retrieval-based JOLs have robustly predicted recall with greater relative accuracy than have the other JOL types. To manipulate self-regulation of study, in Experiments 1A-1C and 2A-2C, we compared conditions in which participants' restudy selections were honored with conditions in which they were completely or randomly dishonored; in Experiments 3A-3C, we randomly honored or dishonored half of the restudy selections and half of the nonselections. Results revealed that the benefit of delayed, retrieval-based JOLs for final memory performance was due largely to the selection of more items for restudy rather than to better discriminations between items that would benefit more versus less from restudy. In most cases, gains in recall due to greater self-regulation of study did not increase with better monitoring accuracy; when they did, the effect was extremely small. The surprising conclusion was that restudy decisions were not very much more efficacious under conditions that yield greater monitoring accuracy than under those that do not.     

Intergroup trust and reciprocity in strategic interactions: Effects of group decision-making mechanisms

I examined the impact of the consensus-making mechanism, where members reach a common decision via an intra-group discussion, on intergroup trust and reciprocity in a strategic setting. Data from a trust game generated the following results. First, compared to individual decision-makers, consensus groups exhibited (a) lower psychological trust, (b) higher behavioral trust, after controlling for psychological trust, and (c) lower reciprocity. Second, compared to decisions made by group-representatives, who are responsible for unilateral decisions on behalf of their groups, group consensus decisions were more trusting but less reciprocating. Thus, the specific decision-making mechanism adopted by groups in a strategic interaction may profoundly change the nature and the interplay of the interaction. Lastly, results show that the level of behavioral trust is driven by reciprocity expectations, while the level of reciprocity behavior, measured as a proportion of the trust received, does not change systematically with the level of trust experienced.     

Manipulating memory associations changes decision-making preferences in a preconditioning task

Memories of past experiences can guide our decisions. Thus, if memories are undermined or distorted, decision making should be affected. Nevertheless, little empirical research has been done to examine the role of memory in reinforcement decision-making. We hypothesized that if memories guide choices in a conditioning decision-making task, then manipulating these memories would result in a change of decision preferences to gain reward. We manipulated participants’ memories by providing false feedback that their memory associations were wrong before they made decisions that could lead them to win money. Participants’ memory ratings decreased significantly after receiving false feedback. More importantly, we found that false feedback led participants’ decision bias to disappear after their memory associations were undermined. Our results suggest that reinforcement decision-making can be altered by false feedback on memories. The results are discussed using memory mechanisms such as spreading activation theories.