Conformity effects in memory as a function of group size,dissenters and uncertainty

In two experimental studies we investigated how false memory reports provided by anonymous group members affect individuals' recognition. Participants were presented with a series of salient and non‐salient objects and recognition memory was subsequently assessed for presented and non‐presented stimuli. In this recognition test, participants were confronted with (in)correct responses from bogus group members. The findings indicate that the bogus answers influenced memory reports only in the absence of a clear recollection and if the stimulus was not judged to be particularly memorable. Moreover, we found no evidence that motivational influences affected participants' judgements. However, the influence of the bogus group decreased with the presence of dissenters who broke the unanimity of the group, and it increased with higher uncertainty. Copyright © 2002 John Wiley & Sons, Ltd.     

Spatial learning in pigs: effects of environmental enrichment and individual characteristics on behaviour and performance

This study investigated the effects of both environmental enrichment and individual behavioural characteristics on spatial cognitive capabilities of pigs, using a novel latent spatial learning paradigm based on Tolman’s detour experiments (1948). Pigs were housed either in ‘barren’ pens or in pens enriched with straw bedding from birth. Pigs were restrained in a Backtest at 10 and 17 days postpartum. Based on their escape behaviour in this test, which has been shown to reflect their behavioural style, six ‘high-resisting’(HR) and six ‘low-resisting’ (LR) pigs were selected from each housing environment (n = 24 in total). At 12 weeks of age, pairs of pen mates (LR and HR) were exposed to a maze three times (exploration trials). Pigs were then placed individually in the maze, and social reinstatement proved to be a strong incentive to find the exit leading to the home pen. We subsequently blocked the direct route to the exit, forcing animals to find a detour (memory test 1, MT1). This test was repeated once to investigate the relative improvement, i.e. detour learning (memory test 2, MT2). Housing condition and Backtest response strongly affected exploration patterns. In spite of this, no effects on performance during the subsequent memory tests were found. Performance was substantially improved in MT2, indicating that once a goal is apparent, pigs are able to solve a complex spatial memory task easily. In conclusion, social reinstatement provided a good incentive to complete a spatial task, and the substantial improvement in performance between MT1 and MT2 stresses the need for task complexity when testing spatial memory in pigs. Housing conditions or individual behavioural style did not affect spatial memory during MT1 or MT2. However, housing environment and behavioural style strongly affected explorative behaviour of pigs in an unfamiliar maze during both exploration trials and memory tests. This implicates that apparent effects of environmental enrichment on spatial learning and memory in pigs might reflect differences in explorative patterns rather than in cognitive processes.     

Working harder to obtain more snack foods when wanting to eat less

This study investigates individual differences in the reinforcing value of snack food. More specifically, it was investigated whether differences in restraint status are associated with differences in working for high-caloric snack food. Thirty-six unrestrained non-dieters, twenty restrained non-dieters and fifteen current dieters performed a concurrent schedules task in which they had the option to work for points for either snack food or fruit and vegetables. By progressively increasing the “price” of the snack foods (i.e., the amount of work required to obtain extra snack points) the relative reinforcing value of snack food was determined. As hypothesized, restrained non-dieters worked harder and current dieters worked less hard to obtain snack food as compared to unrestrained non-dieters.     

Assessment Center Graduate Selection: Decision Processes,Validity, and Evaluation by Candidates

In this contribution, results are presented of research on the predictive validity of a procedure for the career-oriented selection of graduates in The Netherlands. After selection on account of applicant letter, the selection procedure consists of four selective steps: interview with a ‘recruitment officer’, mental test, interview with line manager, and an assessment center comprising two situational exercises. Performance indicators investigated are present salary, average annual changes in function, appraisal of performance, appraisal of management potential, and average annual salary progression. We report on the relationships between the predictors, between the criteria, and between predictors and criteria. The assessment center, together with other steps from the selection procedure, appear to be valid for a number of performance indicators. The correlation between the overall assessment center rating and present salary, corrected for restriction in range, equals 0.55. Stepwise regression indicates that elements from all procedure steps contribute to the prediction of the criterion of average annual salary progression. The disturbing influence of possible ‘crown prince’ -effects on these results, are discussed. Also, the decision process taking place during the end meeting of the assessors is investigated. Finally, the evaluation of the procedure, both by accepted and by rejected candidates, is discussed. These and other results are compared to what is generally known about assessment centers.     

Effects of salience and time pressure on ratings of social causality

A model is proposed to account for the effects of a target person's salience on judgments of that target. It is argued that salience leads to more extreme inferences in the direction implied by prior knowledge that is relevant to the judgment. This knowledge may include both specific information about the target being rated and general information about the class of stimuli to which the target belongs. Two experiments supported these hypotheses. When subjects were under time pressure to make judgments of a target person's influence in a social situation, their judgments increased with the salience of the target when they had prior knowledge that the target was generally high in social influence. However, their judgments decreased with the target's salience when subjects had prior knowledge that the target was generally low in social influence. When subjects were given ample time to make their judgments, however, the effects of target salience were attenuated. Possible implications of these findings for prior research on salience effects are discussed.     

Soccer,rooms, and the quality of your life: Mood effects on judgments of satisfaction with life in general and with specific domains

Two studies on the impact of temporary moods on judgments of satisfaction with life in general and with specific life-domains are reported. It was hypothesized that individuals simplify the complex task of evaluating their life in general by referring to their mood at the time of judgment, but evaluate specific life-domains on the basis of domain-specific information. In accordance with this hypothesis, both studies demonstrated strong mood effects on judgments of general life-satisfaction but only weak and non-significant effects on judgments of specific domain-satisfactions. The findings are interpreted as supporting the hypothesis that affective states serve informative functions.     

The plausibility of the implausible: A critique of Snyder and Swann (1978)

Snyder and Swann (1978) advance an argument that individuals display a cognitive bias in testing hypotheses about the personal attributes of other people, i.e. they seek out information which is supportive of their hypothesis (hypothesis-confirming strategy). It is argued here that these authors confound the hypothesis a person might entertain (belief) with a hypothesis the person is asked to test (assigned task). The findings of two experimental studies in which task and belief were manipulated independently suggest that Snyder and Swann's (1978) results are due to the task manipulation and not to an hypothesis-confirming bias.     

Playing dice with criminal sentences: the influence of irrelevant anchors on experts' judicial decision making

Judicial sentencing decisions should be guided by facts, not by chance. The present research however demonstrates that the sentencing decisions of experienced legal professionals are influenced by irrelevant sentencing demands even if they are blatantly determined at random. Participating legal experts anchored their sentencing decisions on a given sentencing demand and assimilated toward it even if this demand came from an irrelevant source (Study 1), they were informed that this demand was randomly determined (Study 2), or they randomly determined this demand themselves by throwing dice (Study 3). Expertise and experience did not reduce this effect. This sentencing bias appears to be produced by a selective increase in the accessibility of arguments that are consistent with the random sentencing demand: The accessibility of incriminating arguments was higher if participants were confronted with a high rather than a low anchor (Study 4). Practical and theoretical implications of this research are discussed.