Differential item functioning by sex and race in the Hogan Personality Inventory

The authors examined measurement bias in the Hogan Personality Inventory by investigating differential item functioning (DIF) across sex and two racial groups (Caucasian and Black). The sample consisted of 1,579 Caucasians (1,023 men, 556 women) and 523 Blacks (321 men, 202 women) who were applying for entry-level, unskilled jobs in factories. Although the group mean differences were trivial, more than a third of the items showed DIF by sex (38.4%) and by race (37.3%). A content analysis of potentially biased items indicated that the themes of items displaying DIF were slightly more cohesive for sex than for race. The authors discuss possible explanations for differing clustering tendencies of items displaying DIF and some practical and theoretical implications of DIF in the development and interpretation of personality inventories.     

Confidence intervals and replication: where will the next mean fall?

Confidence intervals (CIs) give information about replication, but many researchers have misconceptions about this information. One problem is that the percentage of future replication means captured by a particular CI varies markedly, depending on where in relation to the population mean that CI falls. The authors investigated the distribution of this percentage for varsigma known and unknown, for various sample sizes, and for robust CIs. The distribution has strong negative skew: Most 95% CIs will capture around 90% or more of replication means, but some will capture a much lower proportion. On average, a 95% CI will include just 83.4% of future replication means. The authors present figures designed to assist understanding of what CIs say about replication, and they also extend the discussion to explain how p values give information about replication.     

Adjustments to the correction for attenuation

With respect to the often-present covariance between error terms of correlated variables, D. W. Zimmerman and R. H. Williams's (1977) adjusted correction for attenuation estimates the strength of the pairwise correlation between true scores without assuming independence of error scores. This article focuses on the derivation and analysis of formulas that perform the same function for partial and part correlation coefficients. Values produced by these formulas lie closer to the actual true-score coefficient than do the observed-score coefficients or those obtained by using C. Spearman's (1904) correction for attenuation. The new versions of the formulas thus allow analysts to use hypothetical values for error-score correlations to estimate values for the partial and part correlations between true scores while disregarding the independence-of-errors assumption.     

Profiling local optima in K-means clustering: developing a diagnostic technique

Using the cluster generation procedure proposed by D. Steinley and R. Henson (2005), the author investigated the performance of K-means clustering under the following scenarios: (a) different probabilities of cluster overlap; (b) different types of cluster overlap; (c) varying samples sizes, clusters, and dimensions; (d) different multivariate distributions of clusters; and (e) various multidimensional data structures. The results are evaluated in terms of the Hubert-Arabie adjusted Rand index, and several observations concerning the performance of K-means clustering are made. Finally, the article concludes with the proposal of a diagnostic technique indicating when the partitioning given by a K-means cluster analysis can be trusted. By combining the information from several observable characteristics of the data (number of clusters, number of variables, sample size, etc.) with the prevalence of unique local optima in several thousand implementations of the K-means algorithm, the author provides a method capable of guiding key data-analysis decisions.     

Romantic love and sexual desire in close relationships

Drawing on recent claims in the study of relationships, attachment, and emotion, the authors hypothesized that romantic love serves a commitment-related function and sexual desire a reproduction-related function. Consistent with these claims, in Study 1, brief experiences of romantic love and sexual desire observed in a 3-min interaction between romantic partners were related to distinct feeling states, distinct nonverbal displays, and commitment- and reproductive-related relationship outcomes, respectively. In Study 2, the nonverbal display of romantic love was related to the release of oxytocin. Discussion focuses on the place of romantic love and sexual desire in the literature on emotion.     

Neurocognitive dysfunction in children with sleep disorders

It is well known that adults with sleep disturbances frequently exhibit a wide range of neurocognitive decrements, and that these deficits are potentially reversible with effective treatment. However, the consequences of respiratory sleep disturbances on neurocognitive function in children have only recently been evaluated, and suggest a strong causal association between the episodic hypoxia and sleep fragmentation that characterize the disease and the emergence of reduced memory, attention and intelligence as well as a link to problematic and hyperactive behaviours and mood disturbances. This article takes a critical look at the current literature on these issues, reviews the major findings and discusses such findings in conjunction with those derived from pertinent animal models.     

Hypertension reduction through forgiveness training

The objective of this study was to determine if patients with diagnosed stage-1 hypertension could benefit by a forgiveness training program to achieve measurable reductions in anger expression and blood pressure. Twenty-five participants were randomly divided into wait-listed control and intervention groups. The control group monitored blood pressure while the intervention group participated in an 8-week forgiveness training program. At the end of eight weeks, the wait listed group became an intervention group. Those who received forgiveness training achieved significant reductions in anger expression when compared to the control group. While reductions in blood pressure were not achieved by all the participants, those participants who entered the program with elevated anger expression scores did achieve significant reductions in blood pressure. It is suggested that forgiveness training may be an effective clinical intervention for some hypertensive patients with elevated levels of anger.     

Pure mutism due to simultaneous bilateral lenticulostriate artery territory infarction

A case of pure mutism without pseudobulbar palsy and other neurological findings resulting from simultaneous bilateral lenticulostriate artery territory infarction is presented. A 45-year-old woman suffered a transient ischemic attack with nonfluent aphasia and right hemiparesis. Six months later, she developed pure mutism without oral apraxia, pseudobulbar signs, and motor deficits. Magnetic resonance imaging revealed bilateral infarction in the lentiform nucleus regions. In the available data, there is only one report of simultaneous bilateral lenticulostriate infarction. To date, in all reported cases of mutism of subcortical vascular origin there are also various degrees of pseudobulbar signs and motor deficits and the responsible lesions are mostly consecutive. The case presented here is the first to show pure vascular mutism without other neurological findings.