Weighting of contingency information in causal judgement: Evidence of hypothesis dependence and use of a positive-test strategy

Contingency is an important cue to causation. Research shows that people unequally weight the cells of a 2 × 2 contingency table as follows: cause-present/effect-present (A) > cause-present/effect-absent (B) > cause-absent/effect-present (C) > cause-absent/effect-absent (D). Although some models of causal judgement can accommodate that fact, most of them assume that the weighting of information is invariant as a function of whether one is assessing a hypothesized generative versus preventive relationship. An experiment was conducted that tested the hypothesis-independence assumption against the predictions of a novel weighted-positive-test-strategy account, which predicts hypothesis dependence in cell weighting. Supporting that account, judgements of hypothesized generative causes showed the standard A > B > C > D inequality, but judgements of hypothesized preventive causes showed the predicted B > A > D > C inequality. The findings reveal that cell weighting in causal judgement is both unequal and hypothesis dependent.     

Enclosure shape influences cue competition effects and goal location learning

In virtual-environment spatial-learning procedures, Experiment 1 investigated blocking of learning about distal landmarks beyond the walls of an enclosure following preliminary training to find a goal using local landmarks within the enclosure. Separate sets of blocking and control groups searched within enclosures that, in plan view, formed either a square or a circle. Blocking was apparent when training and testing occurred in the circular but not the square enclosure. In Experiment 2, preliminary training to find a goal using local landmarks blocked spatial learning based on a circular enclosure divided into four differently coloured sections. The results are discussed in relation to theories of incidental versus error-correcting learning linked to different types of spatial cue.     

Insensitivity and oversensitivity to answer diagnosticity in hypothesis testing

Two experiments examined how people perceive the diagnosticity of different answers (“yes” and “no”) to the same question. We manipulated whether the “yes” and the “no” answers conveyed the same amount of information or not, as well as the presentation format of the probabilities of the features inquired about. In Experiment 1, participants were presented with only the percentages of occurrence of the features, which most straightforwardly apply to the diagnosticity of “yes” answers. In Experiment 2, participants received in addition the percentages of the absence of features, which serve to assess the diagnosticity of “no” answers. Consistent with previous studies, we found that participants underestimated the difference in the diagnosticity conveyed by different answers to the same question. However, participants' insensitivity was greater when the normative (Bayesian) diagnosticity of the “no” answer was higher than that of the “yes” answer. We also found oversensitivity to answer diagnosticity, whereby participants valued as differentially diagnostic two answers that were normatively equal in terms of their diagnosticity. Presenting to participants the percentages of occurrence of the features inquired about together with their complements increased their sensitivity to the diagnosticity of answers. We discuss the implications of these findings for confirmation bias in hypothesis testing.     

Categories of Competition

In the first part of this paper, I argue that philosophers of sport have mistakenly privileged a specific psychology and purpose in their definitions of competition. The result of this mistake has been that philosophers of sport make generalisations about competition as such which in fact only hold for some competitions. In the second and third parts of the paper, I articulate an alternative approach: rather than search for a single psychology and purpose that underlies all competition, I argue that we should begin by acknowledging four distinctly different competitive formats, and only then enquire as to which psychologies and purposes are more or less appropriate to each format. This method allows us to capture the richness and diversity of competition, and helps to ensure that we do not confuse part and whole when defining it.     

Adjustment of cognitive control to the frequency of dual-task interference

ABSTRACT

This study explored whether the control mechanisms recruited for optimising performance are similar for dual-task and interference-task settings. We tested whether the frequency of appearance of a secondary task resulted in an adjustment of anticipatory and reflexive forms of attentional control, as has been observed with other interference tasks (e.g. stroop and flanker). The results of two experiments demonstrated a proportion congruency effect (PCE): when a secondary task frequently appeared, primary task performance was slower. Additionally, there was a relative slowdown of dual-task performance in blocks wherein the secondary task appeared infrequently compared to blocks wherein it appeared frequently. However, this slowdown occurred when the primary task entailed a low level of control (Experiment 1) but was absent when it demanded a high level of control (Experiment 2). Overall, the results suggest that level of control can be adjusted to task demands related to the frequency of the secondary task.     

Effects of social context, reinforcer probability, and reinforcer magnitude on humans' choices to compete or not to compete.

In the first two experiments, subjects' choices to earn points (exchangeable for money) either by competing with a fictitious opponent or by not competing were studied. Buskist, Barry, Morgan, and Rossi's (1984) competitive fixed-interval schedule was modified to include a second response option, a noncompetitive fixed-interval schedule. After choosing to enter either option, the opportunity for reinforcers became available after the fixed-interval's duration had elapsed. Under the no-competition condition, points were always available after the interval had elapsed. Under the competition condition, points were available based on a predetermined probability of delivery. Experiments 1 and 2 examined how reinforcer probabilities and reinforcer magnitudes affected subjects' choices to compete. Several general conclusions can be made about the results: (a) Strong preferences to compete were observed at high and moderate reinforcer probabilities; (b) competing was observed even at very low reinforcer probabilities; (c) response rates were always higher in the competition component than in the no-competition component; and (d) response rates and choices to compete were insensitive to reinforcer-magnitude manipulations. In Experiment 3, the social context of this choice schedule was removed to determine whether the high levels of competing observed in the first two experiments were due to a response preference engendered by the social context provided by the experimenters through instructions. In contrast to the first two experiments, these subjects preferred the 60-s fixed-interval schedule (formerly the no-competition option), indicating that the instructions themselves were responsible for the preference to compete. This choice paradigm may be useful to future researchers interested in the effects of other independent variables (e.g., drugs, social context, instructions) on competitive behavior.     

目标结构与学习动机

本文概述了目标结构理论的形成及发展,并进一步论述了在教学中不同的目标结构,导致学生间不间的相互关系,从而使学生形成不同的学习动机,取得不同的学业成就。竞争目标结构激发的是能力中心的动机系统;个体化目标结构激发的是任务掌握的动机系统;合作目标结构激发的是道德中心的动机系统。由此,我们认为在当前的教学实践中应重视合作目标结构的建立。     

When distorted logos are recognized as original? The role of the DRM procedure in detection of immediate and delayed consumers’ errors

IntroductionTo deal effectively with the market, one must create a distinct logo from competing logos. However, it is not uncommon that similarities between logos of various companies are enough to mislead consumers. This paper shows how the DRM paradigm as well as prototype theories can be used to investigate correct and erroneous recognitions of distorted familiar and unfamiliar logos in short- and long-term memory.MethodThe modified hybrid DRM procedure was adopted to test brand images that were distorted but perceptually similar. Participants performed the experimental task in which short- and long-term memory for logos were tested.ResultsThe results demonstrated no difference in memory performance between familiar and unfamiliar logos after a short delay. However, a discrepancy between recognizing both types of logos arose in long term memroy toward more errors for familiar images.ConclusionsThe results confirm that the DRM procedure can be successfully used by marketers as a potential tool in either detecting unfair competition or launching new brands.     

The influence of food distribution on the aggressive behaviour of juvenile white-seabream (Diplodus sargus cadenati de la Paz,Bauchot and Daget, 1974)

Experiments were conducted to investigate the effect of differences in the spatial distribution of food on the aggressive behaviour of juvenile white-seabream, Diplodus sargus cadenati, both in the presence and in the absence of food. The groups of fish receiving spatially fixed food displayed less aggression than those receiving spatially variable food. The period (before, during, or after feeding) during which aggressiveness is measured also has influence in the results. During the prefeeding and postfeeding periods (absence of food), groups that were fed with food spatially fixed displayed less aggression than those that received spatially variable food. However, when food was present there were no differences in the number of aggressive acts carried out by fish groups in both environments. The aggressiveness shown by the groups of fish was always more pronounced during the postfeeding period than during the prefeeding period. The dominant fish was more aggressive when food was spatially fixed, and especially when food was present. Therefore, the subordinates were more aggressive when food was spatially variable and particularly when food was present and during the postfeeding period. Aggr. Behav. 24:379–384, 1998. © 1998 Wiley-Liss, Inc.