Individual differences in reverse Hindsight bias: I never thought something like chernobyl would happen. Did I?

Hindsight bias was studied in the context of the accident in the Chernobyl nuclear power plant, which took place on April 26th 1986. An individual difference factor which relates to the motivation to process information, need for cognition, was expected to moderate the occurrence of hindsight bias. Probability estimates of many casualties due to the use of nuclear power in The Netherlands were obtained from 212 individuals two months before the accident in Chernobyl. These estimates were compared with similar estimates made in hindsight by the same individuals five months after the accident. Loglinear Analyses reveal a systematic hindsight bias. However, the direction of the bias was contrary to expectations. In hindsight, individuals gave lower probabilities than they actually did two months before the Chernobyl accident. These results reveal a reverse hindsight bias. As hypothesized, need for cognition moderates hindsight bias: individuals low and medium in need for cognition express a systematic reverse hindsight bias, while individuals high in need for cognition do not. High need for cognition individuals also show higher literal consistency between the two measurements, which supports a memory explanation of the moderating effect of need for cognition.     

Stochastic ordering using the latent trait and the sum score in polytomous IRT models

In a restricted class of item response theory (IRT) models for polytomous items the unweighted total score has monotone likelihood ratio (MLR) in the latent trait. MLR implies two stochastic ordering (SO) properties, denoted SOM and SOL, which are both weaker than MLR, but very useful for measurement with IRT models. Therefore, these SO properties are investigated for a broader class of IRT models for which the MLR property does not hold.In this study, first a taxonomy is given for nonparametric and parametric models for polytomous items based on the hierarchical relationship between the models. Next, it is investigated which models have the MLR property and which have the SO properties. It is shown that all models in the taxonomy possess the SOM property. However, counterexamples illustrate that many models do not, in general, possess the even more useful SOL property.Hemker's research was supported by the Netherlands Research Council, Grant 575-67-034. Junker's research was supported in part by the National Institutes of Health, Grant CA54852, and by the National Science Foundation, Grant DMS-94.04438.     

Positive affect as implicit motivator: on the nonconscious operation of behavioral goals

Recent research has revealed that nonconscious activation of desired behavioral states--or behavioral goals--promotes motivational activity to accomplish these states. Six studies demonstrate that this nonconscious operation of behavioral goals emerges if mental representations of specific behavioral states are associated with positive affect. In an evaluative-conditioning paradigm, unobtrusive linking of behavioral states to positive, as compared with neutral or negative, affect increased participants' wanting to accomplish these states. Furthermore, participants worked harder on tasks that were instrumental in attaining behavioral states when these states were implicitly linked to positive affect, thereby mimicking the effects on motivational behavior of preexisting individual wanting and explicit goal instructions to attain the states. Together, these results suggest that positive affect plays a key role in nonconscious goal pursuit. Implications for behavior-priming research are discussed.     

War stress and late-life mortality in World War II male civilian resistance veterans

The mental and physical health of 146 Dutch males exposed to severe war stress during their young adulthood were examined in 1986-1987 when they were at ages 61 to 66 years. The veterans' data were compared with a randomly selected population-based sample of same-aged males. In 2005, 70% of the war stress veterans had died, and only 35% of the comparison group. The baseline quality of life was significantly poorer in the war stress veterans than in the comparison group. Baseline variables explained 42% of the increased risk of mortality among war stress veterans. Smoking was the largest single contributor to mortality.     

Reward-driven modulation of adaptive control: How prospective monetary gains interact with unpredictable control demands

Shifting attention is an effortful control process and incurs a cost on the cognitive system. Previous research suggests that rewards, such as monetary gains, will selectively enhance the ability to shift attention when this demand for control is explicitly cued. Here, we hypothesized that prospective monetary gains will selectively enhance the ability to shift attention even when control demand is unpredictable and not cued beforehand in a modality shift paradigm. In two experiments we found that target detection was indeed facilitated by reward signals when an unpredictable shift of attention was required. In these crossmodal trials the target stimulus was preceded by an unpredictive stimulus directing attention to the opposite modality (i.e., visual–auditory or auditory–visual). Importantly, there was no reward effect in ipsimodal trials (i.e., visual–visual or auditory–auditory). Furthermore, the absence of the latter effect could not be explained in terms of physical limits in speed of responding. Potential motivation of monetary rewards thus selectively translates into motivational intensity when control (i.e., switching) is demanded in unpredictable ways.     

Selectors' Decision Strategies when Assessing Immigrant Job Applicants

Immigrant job applicants are often not fluent in the majority language. This raises the question whether selectors adjust their decision strategy when selecting immigrants. In two field studies (N = 1,949 and N = 156), we examined the decision strategies of professional selectors. Selectors used differential strategies, giving less weight to the test scores and impression scores of immigrants. Dutch language proficiency served as a moderator variable; test scores were considered less important in the employment recommendation especially for immigrants with low language skills. Yet professional selectors also used similar strategies for different groups; the same test scores led to the same recommendations, regardless of ethnicity. In sum, personnel selectors adjusted their decision strategy for immigrants, but this did not lead to immigrants receiving higher recommendations than majority applicants with similar test scores.     

Validation and Standardization of the Dutch Trauma Symptom Checklist for Young Children in a Normative and Clinical Sample

The study aimed to describe the psychometric properties of the Dutch version of the Trauma Symptom Checklist for Young Children (TSCYC) in normative and clinical populations in the Netherlands. Caregivers’ ratings on the TSCYC were obtained for 1,802 children from the normal population, and for 515 children from a clinical population of traumatized children. In the clinical sample, additional measures were taken. The internal consistency and test-retest reliability of TSCYC scales were adequate. Confirmatory factor analysis showed acceptable fit on the putative scale structure. Regarding criterion validity, the clinical sample scored significantly higher on all clinical scales when compared to the normal population sample. Within the clinical sample, significant associations were found between TSCYC scales and convergent scales of other instruments. The Posttraumatic Stress-Total subscale demonstrated excellent discriminative ability between traumatized children and children from the normal population. The Dutch version of the TSCYC proved a valid and reliable instrument to measure trauma symptoms in young children through caregiver report, similar to the original American version. Further comparisons with diagnostic interviews are warranted.