Some comments in connection with Rozeboom's linear correlation theory

It is shown that certain correlation measures suggested by information theory are simple functions of the determinants of the correlation matrices involved, if multivariate normality is assumed. This illuminates and in a sense strengthens Rozeboom's point in [3], that information theoretical statistics have classical correlational counterparts.     

Change in cognitive capabilities in the oldest old: the effects of proximity to death in genetically related individuals over a 6-year period

Change in cognitive abilities was assessed over a 6-year period in a sample of monozygotic and same-sex dizygotic twin pairs (N = 507 individuals), aged 80 and older (mean age = 83.3 years: SD = 3.1). who remained nondemented over the course of the study. Latent growth models (LGMs) show that chronological age and time to death are consistent predictors of decline in measures of memory, reasoning, speed, and verbal abilities. Multivariate LGM analysis resulted in weak and often negative correlations among rates of change between individuals within twin pairs, indicating greater differential change within twin pairs than occurs on average across twin pairs. These findings highlight several challenges for estimating genetic sources of variance in the context of compromised health and mortality-related change.     

Dependency and perfectionism: Short-term dynamic group psychotherapy for university students

Abstract

This paper is based on the authors' experiences of conducting short-term psychodynamic group therapy with university students. The therapy groups focus on common problems among the members, i.e. perfectionism, procrastination, and fear of graduation. Working on their dependency and on their inadequate separation from parental figures typically helps the students cope more creatively with their academic problems. The paper explores technical questions and possible advantages in working within a short time frame using a group analytic approach.     

Silence is golden? Characteristics and experiences of self-reported whistleblowers

This study investigates the characteristics of whistleblowers, the prevalence and nature of whistleblowing, and the occurrence of retaliation after whistleblowing using a randomly selected and representative sample of Norwegian employees. The results showed that 12 per cent self-reported as whistleblowers according to an operational definition. Being a leader, or a union or personnel safety representative was significantly related to whistleblowing. The most frequently reported wrongdoing was harassment conducted by a single colleague. Wrongdoer(s) received mixed responses, from no reaction to reprimand. Even though most whistleblowers were not sanctioned, they reported less job satisfaction and more workplace bullying than did nonwhistleblowers. Only a few were rewarded. For the most part, wrongdoing was stopped or reduced. However, whistleblowing was only partially effective, because whistleblowers reported lack of feedback about the result of their report. Results also showed that the status of the wrongdoer was related to the reaction he or she received afterwards, as were the type of wrongdoing and the effect on the wrongdoing, and the type of wrongdoing and the effect on the wrongdoer(s). Potential explanations for the results, such as the type of sample and power distance, are discussed. Practical implications of the study are also addressed, such as the importance of providing feedback to whistleblowers.     

Type 2 Diabetes Mellitus and Cognitive Performance in a Population-Based Sample of the Oldest Old: Impact of Comorbid Dementia

We examined the relationship between type 2 diabetes mellitus and cognitive function in a population-based sample of very old people. The sample comprised 338 persons, aged 80-93 years (mean age 83.5 years), of whom 70 persons had type 2 diabetes mellitus. Measures of cognitive functioning included tests of perceptual speed, visuo-spatial ability, inductive reasoning, short-term memory, semantic memory, episodic memory, and the Mini-Mental State Examination. Regression analyses showed that type 2 diabetes mellitus duration was related to test performance across all cognitive domains, with the exception of short-term memory, such that longer duration was associated with lower test performance. When cases with dementia were excluded from the sample, further analyses showed that diabetes duration was not associated with cognitive test performance. This indicates that diabetes is not related to lower cognitive function in the general population of non-demented old people. Diabetes, however, increases the risk for cerebrovascular incidents, like stroke, that may contribute to vascular dementia.     

Causality in medicine: Towards a theory and terminology

One of the cornerstones of modern medicine is the search for what causes diseases to develop. A conception of multifactorial disease causes has emerged over the years. Theories of disease causation, however, have not quite been developed in accordance with this view. It is the purpose of this paper to provide a fundamental explication of aspects of causation relevant for discussing causes of disease. The first part of the analysis will discuss discrimination between singular and general causality. Singular causality, as in the specific patient, is a relation between a concrete sequence of causally linked events. General causation, e.g. as in disease etiology, means various categories of causal relations between event types. The paper introduces the concept of a reference case serving as a source for causal inference, reaching beyond the concept of general causality. The second part of the analysis provides exemplification of a theory of causation suitable for discussing singular causation. The chain of events that induce a disease state can be identified as effective causal complexes, each complex composed of nonredundant components, which separately contribute to the effect of the complex, without the individual component being necessary or sufficient in itself to produce the effect. In the third part of the analysis the theory is elaborated further. Causes, defined as nonredundant components, can furthermore be differentiated according to their avoidability, according to theories about human error or by the potential of eradication. Multifactorial models of disease creates a need for systematic approaches to causal factors. The paper proposes a taxonomical terminology that serves this purpose.     

INFORMATION LOSS WHEN ρ IS APPLIED IN NON-NORMAL CASES

The correlation coefficient ρ of two stochastic variables underestimates the dependence between the variables, if they are not bivariately normally distributed. An information theoretical approach to the study of this underestimation is suggested. The method is applied on artificial data.