Motivational sources of confirmation bias in criminal investigations: the need for cognitive closure

In two experiments, criminal investigators (N = 50) and undergraduate students (N = 68) read a set of facts from the preliminary investigation of a homicide case. Participants' initial hypothesis regarding the crime was manipulated by providing background information implying that the prime suspect had a jealousy motive or that there might be an alternative perpetrator. Students displayed a framing effect, such that guilt was ascribed to the prime suspect only when a potential motive was presented, whereas investigators did so regardless of hypothesis, thus being less sensitive to alternative interpretations. Investigators' need for cognitive closure (NFC) moderated the effect of the hypothesis on perceptions of the strength of the evidence against the prime suspect; high (v low) NFC investigators were less likely to acknowledge inconsistencies in the material when presented with a potential motive, but were more likely to do so when made aware of the possibility of an alternative perpetrator. Interpretations are somewhat clouded by the fact that dispositional NFC did not seem to affect in a consistent manner participants' motivation toward the experimental task. Copyright © 2005 John Wiley & Sons, Ltd.     

Equivalence of Consequence Operations

This paper is based on Lectures 1, 2 and 4 in the series of ten lectures titled “Algebraic Structures for Logic” that Professor Blok and I presented at the Twenty Third Holiday Mathematics Symposium held at New Mexico State University in Las Cruces, New Mexico, January 8-12, 1999. These three lectures presented a new approach to the algebraization of deductive systems, and after the symposium we made plans to publish a joint paper, to be written by Blok, further developing these ideas. That project was still incomplete when Blok died. In fact, there is no indication that he had prepared a draft of the paper, and we do not know what new material he intended to include. I am therefore not in a position to complete the project as he had envisioned it. So, I have settled for the more limited objective of presenting the material from the three lectures, leaving to others the task of adapting the techniques used there to more general situations. Preface by Bjarni Jónsson Dedicated to the memory of Willem Johannes Blok     

Sleep Architecture in Infants of Substance‐Abusing Mothers

This longitudinal, year‐long study compared sleep–wake state organization in two groups of infants–infants whose mothers abused substances during their pregnancies and nonexposed, typically developing, age‐matched comparison infants–to determine whether differences in sleep–wake state organization existed between the two groups. Seventeen infants of mothers who were participating in a parent–infant residential treatment program for substance abuse were enrolled. Their sleep–wake state organization over the first year of life was compared to that of 17 age‐matched comparison infants. The intent was to follow each infant on five occasions over the first year of life using established methods of time‐lapse videosomnography to record sleep–wake state organization; however, attrition in the substance‐abusing group was problematic. Some sleep–wake variables (i.e., Active Sleep%, Quiet Sleep%, Awake%, number of nighttime awakenings) were similar for both groups of infants at comparable ages across the first year. Total sleep time and the longest sustained sleep period (sleep continuity variables) differed significantly at some of the ages measured. Although overall sleep architecture appears highly resilient and well organized, some indications of sleep fragmentation and shortened nighttime sleep periods were observed in the substance‐exposed infants. More research is needed to explain why sleep‐continuity variables and not sleep‐state proportion variables differed between the two groups.     

Second language vocabulary level is related to benefits for second language listening comprehension under lower reverberation time conditions

The acoustic qualities of a room can have a deleterious effect on the quality of speech signals. The acoustic measurement of reverberation time (RT) has shown to impact second language (L2) speech comprehension positively when lower due to release from spectral and temporal masking effects as well as top-down processing factors. This auralization experiment investigated the benefits of better L2 vocabulary and executive function (updating) skills during L2 listening comprehension tests under shorter versus longer RT conditions (0.3 and 0.9?s). 57 bilingual university students undertook L2 vocabulary, number updating and L2 listening comprehension tests. After splitting groups into high/low vocabulary and updating groups, a mixed ANOVA was conducted. The high number updating group showed no significant differences or interactions in L2 listening comprehension than the lower number updating group across RT conditions. The high vocabulary group had 22% better L2 listening comprehension than the low vocabulary group in long RT, and 9% better in short RT. A significant benefit in L2 listening comprehension due to release from reverberation was only evident in the high vocabulary group. Results indicate that the benefit of good room acoustics for listening comprehension is greatest for those with better language (vocabulary) ability.     

Recall of words heard in noise

The aim of the study was to explore if recall of words and recognition of sentences orally presented was affected by a background noise. A further aim was to investigate the role of working memory capacity in performance in these conditions. Thirty‐two subjects performed a word recall and a sentence recognition test. They repeated each word to ensure that they had heard them. A reading span test measured their working memory capacity. Performance on the word recall task was impaired by the background noise. A high reading span score was associated with a smaller noise effect, especially on recall of the last part of the word list. Copyright © 2007 John Wiley & Sons, Ltd.     

The role of short-term memory capacity and task experience for overconfidence in judgment under uncertainty

Research with general knowledge items demonstrates extreme overconfidence when people estimate confidence intervals for unknown quantities, but close to zero overconfidence when the same intervals are assessed by probability judgment. In 3 experiments, the authors investigated if the overconfidence specific to confidence intervals derives from limited task experience or from short-term memory limitations. As predicted by the naive sampling model (P. Juslin, A. Winman, & P. Hansson, 2007), overconfidence with probability judgment is rapidly reduced by additional task experience, whereas overconfidence with intuitive confidence intervals is minimally affected even by extensive task experience. In contrast to the minor bias with probability judgment, the extreme overconfidence bias with intuitive confidence intervals is correlated with short-term memory capacity. The proposed interpretation is that increased task experience is not sufficient to cure the overconfidence with confidence intervals because it stems from short-term memory limitations.     

Pro-Environmental Habits: Propensity Levels in Behavioral Change1

A proposed model for behavioral change is described as a process in several steps from habitual nonenvironmentally friendly behavior to environmentally friendly behavior. Every step is linked to factors promoting or impeding further progress. Data from a questionnaire addressed to a random sample of 500 Swedish adults supported the hypothesis that general factors such as environmental values and a sense of responsibility for the environment will be more influential in an early phase rather than in a later phase of changing established habits regarding purchases of washing and washing-up detergents, respectively. Furthermore, in a later phase of transition, specific beliefs about particular products will affect the testing and evaluation of a new behavior.     

Simultaneous factor analysis of dichotomous variables in several groups

A new method is proposed for a simultaneous factor analysis of dichotomous responses from several groups of individuals. The method makes it possible to compare factor loading pattern, factor variances and covariances, and factor means over groups. The method uses information from first and second order proportions and estimates the model by generalized least-squares. Hypotheses regarding different degrees of invariance over groups may be evaluated by a large-sample chi-square test.The research of the first author was supported partly by the Bank of Sweden Tercentenary Foundation under project Structural Equation Models in the Social Sciences, project director Karl G. Jöreskog, and partly by the Swedish Research Council in the Humanistic and Social Sciences under project Analysis of Contingency Tables, project director Bengt Muthén.