Group choice: competition, travel, and the ideal free distribution

If a group of foragers distributes among resource patches according to the ideal free distribution, the relative number of foragers in each patch should match the relative amount of resource obtained there, unless deviations arise from factors such as incomplete information or interforager interference. In analogy to individual choice, such effects may produce undermatching—group distribution falling short of resource distribution—or overmatching—group distribution overshooting resource distribution. In the present experiments, a flock of about 30 pigeons distributed between two patches with continuous inputs of green peas. Competition was varied by changing the size or extent of the patches. When the patches were areas or troughs, some undermatching occurred. When the patches were small bowls, strong undermatching occurred. When travel was required to switch patches, undermatching decreased slightly. A visual barrier that prevented pigeons from seeing one patch from the other had no effect. Overall rate of food delivery, varied over a wide range, had no effect. It appeared that the mechanism of flock distribution depended on comparisons between patches that were successive rather than simultaneous. Although most pigeons participated in the experiments, and different pigeons participated to different extents, individual pigeons tended to be consistent in the extent of participation from session to session, suggesting the possibility that participation might reflect competitive ability. Examination of the preferences and switching of individual pigeons revealed no consistency within or across individuals. It appeared that the flock's distribution was a truly emergent phenomenon, in the sense that results at the level of the flock in no way paralleled behavior at the level of the individual.     

How can individual differences in autobiographical memory distributions of older adults be explained?

The reminiscence bump phenomenon has frequently been reported for the recall of autobiographical memories. The present study complements previous research by examining individual differences in the distribution of word-cued autobiographical memories. More importantly, we introduce predictor variables that might account for individual differences in the mean (location) and the standard deviation (scale) of individual memory distributions. All variables were derived from different theoretical accounts for the reminiscence bump phenomenon. We used a mixed location-scale logitnormal model, to analyse the 4602 autobiographical memories reported by 118 older participants. Results show reliable individual differences in the location and the scale. After controlling for age and gender, individual proportions of first-time experiences and individual proportions of positive memories, as well as the ratings on Openness to new Experiences and Self-Concept Clarity accounted for 29% of individual differences in location and 42% of individual differences in scale of autobiographical memory distributions. Results dovetail with a life-story account for the reminiscence bump which integrates central components of previous accounts.     

德沃金的资源平等论探微

德沃金根据抽象的平等权理论对自由主义的分配正义理论作了新的阐发,提出了资源平等论,这一理论构想包括拍卖模式和虚拟保险市场两个部分,分别解决初始分配和再次分配的平等问题。该理论特别强调个人的自由选择权利。这一理论的完备性还有待进一步检验。     

社会距离与分配差距对儿童有利不公平厌恶的影响

选取60名8-10岁儿童,采用迫选式独裁者游戏,考察个体与博弈对象的社会距离以及分配差距对儿童有利不公平厌恶的影响。结果发现：（1）在有利不公平条件下,与博弈对象社会距离越近,儿童对不公平分配提议的拒绝率越高;（2）分配差距越大,儿童对不公平分配提议的拒绝率越高;（3）社会距离和分配差距交互作用显著,在中等分配差距条件下,儿童对不公平分配提议拒绝率的社会距离效应最为明显。结果表明,社会距离和分配差距对儿童有利不公平厌恶有显著影响,在中度分配差距下社会距离具有更加明显的调节作用。     

Within-culture variation in the content of stereotypes: Application and development of the stereotype content model in an Eastern European culture

There is little and unsystematic evidence about whether the content of stereotypes can vary within a culture. Using the Stereotype Content Model (SCM) as a theoretical framework, in two studies we examined the content of stereotypes in an Eastern European culture, namely Romania. Data were collected from four regions prototypical in terms of economic and social development in Romania, and we examined whether the content of stereotypes varies across these regions. As expected, the findings confirm the applicability of the SCM in Romania to reveal culture-specific stereotypes and provide initial support for within-culture variation in the content of stereotypes. We discuss, in particular, possible reasons for two main findings: a strong one-dimensional structure of stereotypes, and regional differences in stereotype content.     

Age slowing down in detection and visual discrimination under varying presentation times

The reaction time has been described as a measure of perception, decision making, and other cognitive processes. The aim of this work is to examine age‐related changes in executive functions in terms of demand load under varying presentation times. Two tasks were employed where a signal detection and a discrimination task were performed by young and older university students. Furthermore, a characterization of the response time distribution by an ex‐Gaussian fit was carried out. The results indicated that the older participants were slower than the younger ones in signal detection and discrimination. Moreover, the differences between both processes for the older participants were higher, and they also showed a higher distribution average except for the lower and higher presentation time. The results suggest a general slowdown in both tasks for age under different presentation times, except for the cases where presentation times were lower and higher. Moreover, if these parameters are understood to be a reflection of executive functions, these findings are consistent with the common view that age‐related cognitive deficits show a decline in this function.     

The Generalized Quantum Episodic Memory Model

Recent evidence suggests that experienced events are often mapped to too many episodic states, including those that are logically or experimentally incompatible with one another. For example, episodic over‐distribution patterns show that the probability of accepting an item under different mutually exclusive conditions violates the disjunction rule. A related example, called subadditivity, occurs when the probability of accepting an item under mutually exclusive and exhaustive instruction conditions sums to a number >1. Both the over‐distribution effect and subadditivity have been widely observed in item and source‐memory paradigms. These phenomena are difficult to explain using standard memory frameworks, such as signal‐detection theory. A dual‐trace model called the over‐distribution (OD) model (Brainerd & Reyna, 2008) can explain the episodic over‐distribution effect, but not subadditivity. Our goal is to develop a model that can explain both effects. In this paper, we propose the Generalized Quantum Episodic Memory (GQEM) model, which extends the Quantum Episodic Memory (QEM) model developed by Brainerd, Wang, and Reyna (2013). We test GQEM by comparing it to the OD model using data from a novel item‐memory experiment and a previously published source‐memory experiment (Kellen, Singmann, & Klauer, 2014) examining the over‐distribution effect. Using the best‐fit parameters from the over‐distribution experiments, we conclude by showing that the GQEM model can also account for subadditivity. Overall these results add to a growing body of evidence suggesting that quantum probability theory is a valuable tool in modeling recognition memory.     

The just world hypothesis as an argumentative resource in debates about unemployment benefits

The concept of the “just world” is established as a key explanation for how people make sense of inequality so that those deemed to score high in belief in a just world are more likely to hold prejudicial beliefs and to blame people in poverty for their situations. However, this is an inadequate explanation for such complicated and controversial issues. To better understand talk about the just world and the controversial issue of the distribution of unemployment benefits (an issue of inequality), a discursive psychological approach to the just world is used. Therefore, a discourse analysis focusses on 2 feature length British televised discussions about benefit claimants called “The Big Benefit Row: Live” (Channel 5 3/2/2014) and “Benefits Britain: the Debate” (Channel 4 17/2/2014). The analysis demonstrates that people draw on both just and unjust world arguments simultaneously and also topicalise what counts as just so as to support their positions on unemployment benefits, rather than in the consistent way that just world theory would predict. It is therefore argued that the just world should be recast as a cultural value that facilitates arguments about benefits, rather than an internally held belief.     

心理不安全状态下决策者的风险偏好

心理不安全感是指人们对可能遭受的伤害与威胁的担忧与焦虑。当下, 许多个体都是在心理不安全的状态下进行决策。对于心理不安全状态下的风险偏好规律, 现有研究得到了矛盾的结果。此外, 心理安全感对风险偏好的作用机制尚不明确。本研究聚焦心理安全感对风险偏好的影响, 考察心理安全感的补偿机制在其中的中介作用, 并探讨选项分布情况在其中的调节作用, 以此揭示心理安全感为何及如何作用于风险偏好。研究结果将有助于明确决策者在心理不安全状态下的风险偏好规律, 从而完善现有的风险决策理论。同时, 为公共管理政策制定提供科学依据。     

Small wonders of the Indian market

Heavy competition in India in almost all product categories, due to diversification by large and medium companies and increased entry of multinationals, has restricted the growth of domestic companies. Previously, large companies enjoyed high profit margins by targeting premium priced products in the upper strata of Indian society. High levels of competition from equally reputed brands have not only decreased the companies' market share but also created price wars, reducing profit margins and limiting market growth. This has motivated companies to consider the lower classes and the rural segments, which they had previously ignored. By targeting these segments with products in small packs at lower price points, companies have experienced great success. At the same time, small packs also pose some challenges for the companies. This paper explains the importance of small packs for market expansion in various product categories within the Indian market, drawing on several examples to support the views of the authors. Copyright © 2004 Henry Stewart Publications.