When is the Wilcoxon–Mann–Whitney procedure a test of location? Implications for effect-size measures

The Wilcoxon–Mann–Whitney procedure is invariant under monotone transformations but its use as a test of location or shift is said not to be so. It tests location only under the shift model, the assumption of parallel cumulative distribution functions (cdfs). We show that infinitely many monotone transformations of the measured variable produce parallel cdfs, so long as the original cdfs intersect nowhere or everywhere. Thus there are infinitely many effect sizes measured as shifts of medians, invalidating the notion that there is one true shift parameter and thereby rendering any single estimate dubious. Measuring effect size using the probability of superiority alleviates this difficulty.     

Quantitative chromatographic profiling of odours associated with dominance in male laboratory mice

Triads of male NMRI mice were housed together and dominance hierarchies allowed to form. At age 19 weeks the mice were ranked on the basis of wins in spontaneous aggressive encounters, and whole-body volatiles were sampled by the dynamic solvent effect and quantitatively analysed by capillary gas chromatography. At age 26 weeks the mice were again ranked on the basis of wins in aggressive encounters, number of aggressive encounters initiated, and scent marking patterns, and whole-body volatiles were sampled and analysed. Chromatographic odour profile ranks agreed perfectly with aggressive initiator ranks and poorly with encounter winner ranks. Eight components of the whole-body odour were identified by gas chromatography-mass spectrometry; two of these are known semiochemicals. The results demonstrate that murine semiochemicals are accessible to quantitative analysis at the level of the individual.     

Cognitive complexity of social images revealed by Jewish Israeli adolescents relating to drawings of Jews and Arabs

The present study examined age‐related differences among Israeli youth regarding the complexity of their mental images of Jews and Arabs, two groups that are adversaries in the Middle East conflict. The participants, 494 Jewish children and adolescents ranging from 8–16 years old each, drew two human figures, one Jewish and one Arab, and then attributed a forename and a profession to each drawn image. Four complexity variables were scored as follows: image complexity (number of items included in the figure), embellishments (number of items added to the drawing and in the space around the figure), image name, and image profession. Overall, participants depicted members of their in‐group as more complex. However, early adolescence was found to be a critical age at which differences emerged. The findings suggest that introducing complexity to social representations in early adolescence may facilitate prevention of negative associations related to outgroups and enhance intervention to reduce stereotypes, prejudice, and racism.     

Influence of individual differences in working memory on the continued influence effect of misinformation

ABSTRACT

Misinformation often continues to influence people’s cognition even after being retracted (the continued influence effect of misinformation, CIE). The current research aimed to investigate whether the individual differences in the central executive function of WM and updating could influence the CIE of misinformation with varying relevance. The results showed that the individual differences in central executive function could significantly affect the CIE, especially for the high-relevant misinformation. While the individual differences in the updating ability had a weaker impact on the CIE in general and only negatively related to the CIE for the low-relevant misinformation. The study extends the understanding of the relationship between individual differences and the CIE from previous studies, which is in line with the mental-model-updating hypothesis, and offers a preliminary clue for identifying the persons vulnerable to the CIE of misinformation in the real world.     

Social learning under the labeling effect: Exploring travellers’ behavior in social dilemmas

This paper presents results of a laboratory experiment, in which subjects made choices between public and private transportation when managing Personal Carbon Allowances (PCAs). The objectives of this study were twofold. Firstly, it was aimed at investigating the labeling effect under the social dilemma context. Secondly, it showed insights into the decision-making process when feedback about others’ choices was provided. A combination of the labeling effect and feedback helped individuals change their commuting pattern and increase the number of trips by public transportation under the PCAs regime. Feedback on others’ choices resulted in social learning and incentivized choice of public transportation more frequently in social dilemma situations.     

系列范畴词表时序记忆和项目记忆研究

该项研究探讨系列范畴词表的时序长时记忆和项目长时记忆,实验设计的系列范畴词表将记忆项目分为词表内范畴相同项和词表间范畴相同项,时序记记测量方法是词表辨认,项目记忆测量方法是自由回忆。实验一发现：２分钟延缓测试词表内范畴相同项时序记忆和项目记忆优于词表间范畴相同项;６分钟以及１０分钟延缓测试时序记忆仍是词表内范畴相同项好。实验二发现：以范畴线索提取,两类项目记忆没有显著差异;以词表线索提取,两类项目     

Similarity and reluctance to trade

Previous research has shown that after decision makers are endowed with an object, they are reluctant to trade it for an alternative item. This endowment effect can be explained by loss aversion, the tendency to weight losses more heavily than gains. Consequently, there is no reluctance to trade when no true loss is involved. Four studies investigated whether reluctance to trade declines when the trade involves less of a loss—specifically, when one item is traded for another very similar item. Three experiments did not reveal a relation between willingness to trade and the similarity between the two items being traded. A fourth experiment, however, indicated that subjects were quite willing to trade for an identical item, less willing to trade for a similar item, and even less willing to trade for a dissimilar item. Thus, reluctance to trade decreased as the similarity between the endowment and the alternative increased. This result suggests that loss aversion is a function not only of the item being lost but also of the trade itself—that is, of the relation between the two items being traded. © 1998 John Wiley & Sons, Ltd.