Assessing Drug Consumption Behavior With the Heidelberger Drogenbogen (Heidelberg Drug Scales): Reliabilities, Validities, and Cut-Off Criteria.

BACKGROUND: The Heidelberger Drogenbogen (HDB) is a German language assessment of substance-specific knowledge and consumption patterns of the illicit psychoactive substances cannabis, MDMA (ecstasy), amphetamines, cocaine, and hallucinogens. The behavior modules for each of these five drugs/drug groups allow for a diagnostic evaluation of the extent of harmful consumption behavior. Each of the five modules represents a single standardized test. OBJECTIVES: This paper outlines several statistical parameters, Cronbach's alpha, retest reliabilities, as well as numerous validity and cut-off-criteria of the behavioral modules. METHODS: Participants (N = 4,794) were recruited at schools, universities, in subcultural contexts, and in institutions of substance abuse treatment. RESULTS: Internal consistencies range from = .68 to .79 while test-retest reliabilities between .87 and .94 were found. The behavior modules of the HDB can discriminate between populations with and without clinical levels of substance use. Furthermore, this measure has incremental validity and higher diagnostic accuracy over competing measures. CONCLUSIONS: The behavior modules of the HDB are reliable and valid measures of substance use and misuse.

Three-month B vitamin supplementation in pre-school children affects folate status and homocysteine, but not cognitive performance.

BACKGROUND: Suboptimal vitamin B status might affect cognitive performance in early childhood. We tested the hypothesis that short-term supplementation with folic acid and selected B vitamins improves cognitive function in healthy children in a population with relatively low folate status. METHODS: We screened 1,002 kindergarten children for suboptimal folate status by assessing the total urinary para-aminobenzoylglutamate excretion. Two hundred and fifty low ranking subjects were recruited into a double blind, randomized, controlled trial to receive daily a sachet containing 220 µg folic acid, 1.1 mg vitamin B2, 0.73 mg B6, 1.2 µg B12 and 130 mg calcium, or calcium only for 3 months. Primary outcomes were changes in verbal IQ, short-term memory and processing speed between baseline and study end. Secondary outcomes were urinary markers of folate and vitamin B12 status, acetyl-para-aminobenzoylglutamate and methylmalonic acid, respectively, and, in a subgroup of 120 participants, blood folate and plasma homocysteine. RESULTS: Pre- and post-intervention cognitive measurements were completed by 115 children in the intervention and 122 in the control group. Compared to control, median blood folate increased by about 50% (P for difference, P < 0.0001). Homocysteine decreased by 1.1 µmol/L compared to baseline, no change was seen in the control group (P for difference P < 0.0001) and acetyl-para-aminobenzoylglutamate was 4 nmol/mmol higher compared to control at the end of the intervention (P < 0.0001). We found no relevant differences between the groups for the cognitive measures. CONCLUSION: Short-term improvement of folate and homocysteine status in healthy children does not appear to affect cognitive performance.

Differential effects of cognitive inhibition and intelligence on creativity.

There are different conceptions about how cognitive inhibition is related to creativity. Creativity has either been associated with effective inhibition, or with disinhibition, or with an adaptive engagement of inhibition. In this study, we examined the relationship of cognitive inhibition, assessed by means of the random motor generation task, with different measures of creativity. We also analyzed whether this relation is mediated by intelligence. We generally found a positive correlation of inhibition and creativity measures. Moreover, latent variable analyses indicate that inhibition may primarily promote the fluency of ideas, whereas intelligence specifically promotes the originality of ideas. These findings support the notion that creative thought involves executive processes and may help to better understand the differential role of inhibition and intelligence in creativity.

Psychometric evaluation and experimental validation of the statistics anxiety rating scale.

The Statistics Anxiety Rating Scale (STARS) was adapted into German to examine its psychometric properties (n = 400). Two validation studies (n = 66, n = 96) were conducted to examine its criterion-related validity. The psychometric properties of the questionnaire were very similar to those previously reported for the original English version in various countries and other language versions. Confirmatory factor analysis indicated 2 second-order factors: One was more closely related to anxiety and the other was more closely related to negative attitudes toward statistics. Predictive validity of the STARS was shown both in an experimental exam-like situation in the laboratory and during a real examination situation. Taken together, the findings indicate that statistics anxiety as assessed by the STARS is a useful construct that is more than just an expression of a more general disposition to anxiety.

Anomalous results in G-factor models: Explanations and alternatives.

G-factor models such as the bifactor model and the hierarchical G-factor model are increasingly applied in psychology. Many applications of these models have produced anomalous and unexpected results that are often not in line with the theoretical assumptions on which these applications are based. Examples of such anomalous results are vanishing specific factors and irregular loading patterns. In this article, the authors show that from the perspective of stochastic measurement theory anomalous results have to be expected when G-factor models are applied to a single-level (rather than a 2-level) sampling process. The authors argue that the application of the bifactor model and related models require a 2-level sampling process that is usually not present in empirical studies. We demonstrate how alternative models with a G-factor and specific factors can be derived that are more well-defined for the actual single-level sampling design that underlies most empirical studies. It is shown in detail how 2 alternative models, the bifactor-(S - 1) model and the bifactor-(S·I - 1) model, can be defined. The properties of these models are described and illustrated with an empirical example. Finally, further alternatives for analyzing multidimensional models are discussed. (PsycINFO Database Record

The Impact of Symmetry: Explaining Contradictory Results Concerning Working Memory, Reasoning, and Complex Problem Solving.

Findings of studies on the unique effects of reasoning and working memory regarding complex problem solving are inconsistent. To find out if these inconsistencies are due to a lack of symmetry between the studies, we reconsidered the findings of three published studies on this issue, which resulted in conflicting conclusions regarding the inter-relations between reasoning, working memory, and complex problem solving. This was achieved by analysing so far unpublished problem solving data from the study of Bühner, Krumm, Ziegler, and Plücken (2006) (N= 124). One of the three published studies indicated unique effects of working memory and reasoning on complex problem solving using aggregated scores, a second study found no unique contribution of working memory using only figural scores, and a third study reported a unique influence only for reasoning using only numerical scores. Our data featured an evaluation of differences across content facets and levels of aggregation of the working memory scores. Path models showed that the results of the first study could not be replicated using content aggregated scores; the results of the second study could be replicated if only figural scores were used, and the results of the third study could be obtained by using only numerical scores. For verbal content, none of the published results could be replicated. This leads to the assumption that not only symmetry is an issue when correlating non-symmetrical data, but that content also has to be taken into account when comparing different studies on the same topic.

A Vast Graveyard of Undead Theories: Publication Bias and Psychological Science's Aversion to the Null.

Publication bias remains a controversial issue in psychological science. The tendency of psychological science to avoid publishing null results produces a situation that limits the replicability assumption of science, as replication cannot be meaningful without the potential acknowledgment of failed replications. We argue that the field often constructs arguments to block the publication and interpretation of null results and that null results may be further extinguished through questionable researcher practices. Given that science is dependent on the process of falsification, we argue that these problems reduce psychological science's capability to have a proper mechanism for theory falsification, thus resulting in the promulgation of numerous "undead" theories that are ideologically popular but have little basis in fact.

Masking misfit in confirmatory factor analysis by increasing unique variances: a cautionary note on the usefulness of cutoff values of fit indices.

Fit indices are widely used in order to test the model fit for structural equation models. In a highly influential study, Hu and Bentler (1999) showed that certain cutoff values for these indices could be derived, which, over time, has led to the reification of these suggested thresholds as "golden rules" for establishing the fit or other aspects of structural equation models. The current study shows how differences in unique variances influence the value of the global chi-square model test and the most commonly used fit indices: Root-mean-square error of approximation, standardized root-mean-square residual, and the comparative fit index. Using data simulation, the authors illustrate how the value of the chi-square test, the root-mean-square error of approximation, and the standardized root-mean-square residual are decreased when unique variances are increased although model misspecification is present. For a broader understanding of the phenomenon, the authors used different sample sizes, number of observed variables per factor, and types of misspecification. A theoretical explanation is provided, and implications for the application of structural equation modeling are discussed.

The bystander-effect: a meta-analytic review on bystander intervention in dangerous and non-dangerous emergencies.

Research on bystander intervention has produced a great number of studies showing that the presence of other people in a critical situation reduces the likelihood that an individual will help. As the last systematic review of bystander research was published in 1981 and was not a quantitative meta-analysis in the modern sense, the present meta-analysis updates the knowledge about the bystander effect and its potential moderators. The present work (a) integrates the bystander literature from the 1960s to 2010, (b) provides statistical tests of potential moderators, and (c) presents new theoretical and empirical perspectives on the novel finding of non-negative bystander effects in certain dangerous emergencies as well as situations where bystanders are a source of physical support for the potentially intervening individual. In a fixed effects model, data from over 7,700 participants and 105 independent effect sizes revealed an overall effect size of g = -0.35. The bystander effect was attenuated when situations were perceived as dangerous (compared with non-dangerous), perpetrators were present (compared with non-present), and the costs of intervention were physical (compared with non-physical). This pattern of findings is consistent with the arousal-cost-reward model, which proposes that dangerous emergencies are recognized faster and more clearly as real emergencies, thereby inducing higher levels of arousal and hence more helping. We also identified situations where bystanders provide welcome physical support for the potentially intervening individual and thus reduce the bystander effect, such as when the bystanders were exclusively male, when they were naive rather than passive confederates or only virtually present persons, and when the bystanders were not strangers.