Emergent Power Hierarchies and Group Performance

In newly formed groups, informal hierarchies emerge automatically and readily. In this study, we argue that emergent group hierarchies enhance group performance (Hypothesis 1) and we assume that the more the power hierarchy within a group corresponds to the task‐competence differences of the individual group members, the better the group performs (Hypothesis 2). Twelve three‐person groups and 28 four‐person groups were investigated while solving the Winter Survival Task. Results show that emerging power hierarchies positively impact group performance but the alignment between task‐competence and power hierarchy did not affect group performance. Thus, emergent power hierarchies are beneficial for group performance and although they were on average created around individual group members' competence, this correspondence was not a prerequisite for better group performance.     

A Signal Detection Model for Multiple-Choice Exams

A model for multiple-choice exams is developed from a signal-detection perspective. A correct alternative in a multiple-choice exam can be viewed as being a signal embedded in noise (incorrect alternatives). Examinees are assumed to have perceptions of the plausibility of each alternative, and the decision process is to choose the most plausible alternative. It is also assumed that each examinee either knows or does not know each item. These assumptions together lead to a signal detection choice model for multiple-choice exams. The model can be viewed, statistically, as a mixture extension, with random mixing, of the traditional choice model, or similarly, as a grade-of-membership extension. A version of the model with extreme value distributions is developed, in which case the model simplifies to a mixture multinomial logit model with random mixing. The approach is shown to offer measures of item discrimination and difficulty, along with information about the relative plausibility of each of the alternatives. The model, parameters, and measures derived from the parameters are compared to those obtained with several commonly used item response theory models. An application of the model to an educational data set is presented.     

The role of perceptual similarity of the task environments in children’s perseverative responding

Perseverative responding is often seen in children’s performance in a variety of contexts. One such context is symbolic comprehension in which 2- and 2½-year-olds demonstrate difficulty in appreciating the association of symbols (pictures and scale models) and their referents and show a high proportion of perseverative responding. Representational-level explanations of perseveration were explored in the current studies via examination of the impact of perceptual similarity of visual environments across trials. Across two experiments, children saw either a picture (Experiment 1) or a scale model (Experiment 2) of a hiding location of a room and were then encouraged to recover the toy from an identical room. Manipulating the perceptual similarity of the environments across successive trials affected performance and perseverative responding. These results highlight the critical role played by perceptual information not only in symbolic tasks but also in many other tasks and have important implications for theories of perseveration.     

A Test of the Adams-Creamer Decay Hypothesis for the Timing of Motor Responses

The Adams-Creamer hypothesis states that S uses the decay of proprioceptive feedback from an early portion of a movement to cue a timed response at some later time. This hypothesis was tested by creating passive left-arm movement in one group and withholding it from another, and having Ss make a right-hand response when exactly 2.0 sec. had elapsed since the end of the movement Ss with left-arm feedback had less absolute and algebraic error, and greater within-S consistency than did the no-movement control Ss and, when KR was withdrawn, Ss with left-arm movement regressed less than did Ss without the left-arm movement, which provided 2 lines of support for the decay hypothesis.     

A validation of a computerised task of risk-taking and moral decision-making and its association with sensation-seeking,impulsivity and sociomoral reasoning

The aim of this study was to investigate the reliability and validity of the computer based application of the Secret Agent (SA) task of risk-taking and moral decision-making. The participants were 100 male patients in a maximum security hospital (50 with severe mental illness and 50 with personality disorder) and 50 community based healthy controls. All participants completed the SA task, the Iowa Gambling Task (IGT), and measures of IQ, antisocial personality traits, sensation-seeking, impulsivity and sociomoral reasoning. The SA risk-taking and moral decision-making scales had satisfactory levels of reliability (Cronbach’s alpha). Risk-taking correlated significantly with sensation-seeking across all three participant groups. In contrast, risk-taking only correlated with impulsivity among the severe mental illness group. Moral decision-making correlated with sociomoral reasoning among the personality disorder group. No correlation was found between the SA scores and the IGT score and the IGT did not correlate with sensation-seeking or impulsivity. IQ and antisocial personality traits did not correlate with the SA or IGT scales. The study highlights the importance of context, the nature of the risk-taking task, and ‘problem framing’ of the instructions in their relationship with individual differences.     

Positive affect facilitates task switching in the dimensional change card sort task: Implications for the shifting aspect of executive function

Using the modified Dimensional Change Card Sort task, we examined the influence of positive affect on task switching by inspecting various markers for the costs, including restart cost, switch cost and mixing cost. Given that the executive-control processes that underlie switching performance—i.e., inhibition or shifting—are distinct from the component processes that underlie non-switching performance—i.e., stimulus evaluation, resource allocation or response execution—we hypothesised that if positive affect facilitates task switching via executive-control processes, rather than via component processes, positive affect would reduce both switch and restart costs, but not mixing cost, because both switch and restart costs rely on executive processes, while mixing cost imposes only minimal demands on executive processes. We found beneficial effects of positive affect on both restart and switch costs, but not on mixing costs. These results suggest that positive affect improves switching abilities via executive processes rather than via component processes.     

Task conflict,information processing,and decision-making: The damaging effect of relationship conflict

A popular theoretical assumption holds that task-related disagreements stimulate critical thinking, and thus may improve group decision making. Two recent meta-analyses showed, however, that task conflict can have a positive effect, a negative effect, or no effect at all on decision-making quality (De Dreu & Weingart, 2003; De Wit, Greer, & Jehn, 2012). In two studies, we built upon the suggestion of both meta-analyses that the presence of relationship conflict determines whether a task conflict is positively or negatively related to decision making. We hypothesized and found that the level of perceived relationship conflict during task conflict (Study 1), and the actual presence (vs. absence) of relationship conflict during task conflict (Study 2), increased group members’ rigidity in holding onto suboptimal initial preferences during decision making and thus led to poor decisions. In both studies the effect of relationship conflict on decision making was mediated by biased use of information.     

Developmental changes of win-stay and loss-shift strategies in decision making

This study aims to clarify the developmental changes in real-life decision making when strategy is adjusted using both positive and negative feedback, that is, whether strategic adjustment evolves with age. A total of 84 participants divided into three age groups (children, adolescents, and adults) performed the standard version of the Iowa Gambling Task (IGT). Children and adolescents showed a strong bias in favor of disadvantageous choices whereas adults learned to decide advantageously during the course of the task. Interestingly, the results clearly demonstrate that children did not switch differently following gains and losses whereas adolescents and adults switched more often after a loss than after a gain, corresponding to the “loss-shift” and the “win-stay” strategies, respectively. The results also revealed that adults switched less often after losses compared to children and adolescents and, thus, used the loss-stay strategy more often than the 2 youngest groups. These new findings suggest that successful completion of the IGT by adults requires fine feedback monitoring and more frequent use of the win-stay and loss-stay strategic adjustments.     

Differential attentional allocation and subsequent recognition for young and older adult faces

Studies examining own-age recognition biases report inconsistent results and often utilize paradigms that present faces individually and in isolation. We investigated young and older adults' attention towards young and older faces during learning and whether differential attention influences recognition. Participants viewed complex scenes while their eye movements were recorded; each scene contained two young and two older faces. Half of the participants formed scene impressions and half prepared for a memory test. Participants then completed an old/new face recognition task. Both age groups looked longer at young than older faces; however, only young adults showed an own-age recognition advantage. Participants in the memory condition looked longer at faces but did not show enhanced recognition relative to the impressions condition. Overall, attention during learning did not influence recognition. Our results provide evidence for a young adult face bias in attentional allocation but suggest that longer looking does not necessarily indicate deeper encoding.