DNA COLLECTION IN A RANDOMIZED SOCIAL SCIENCE STUDY OF COLLEGE PEER EFFECTS

We describe the DNA collection processes of an initial pilot and full study, which is designed to investigate joint peer and genetic effects on health behaviors and attitudes in a college campus setting. In the main study, 2664 (79.5%) students completed a Web survey and 2080 (78.7% of the survey completers after adjusting for the ineligible) provided a saliva DNA sample. The response rate for completing both the survey and the DNA portion of the study is 62.5%. Our DNA yields are of high quality. Overall, our experiences and results demonstrate that genetic data can be successfully collected as a part of traditional social science survey research projects. To aid others in doing so, we provide extensive details of our data collection experiences and offer recommendations to future researchers seeking to do or evaluate similar work.     

Translating cross-lagged effects into incidence rates and risk ratios: The case of psychosocial safety climate and depression

Longitudinal studies are the gold standard of empirical work and stress research whenever experiments are not plausible. Frequently, scales are used to assess risk factors and their consequences, and cross-lagged effects are estimated to determine possible risks. Methods to translate cross-lagged effects into risk ratios to facilitate risk assessment do not yet exist, which creates a divide between psychological and epidemiological work stress research. The aim of the present paper is to demonstrate how cross-lagged effects can be used to assess the risk ratio of different levels of psychosocial safety climate (PSC) in organisations, an important psychosocial risk for the development of depression. We used available longitudinal evidence from the Australian Workplace Barometer (N?=?1905) to estimate cross-lagged effects of PSC on depression. We applied continuous time modelling to obtain time-scalable cross effects. These were further investigated in a 4-year Monte Carlo simulation, which translated them into 4-year incident rates. Incident rates were determined by relying on clinically relevant 2-year periods of depression. We suggest a critical value of PSC?=?26 (corresponding to ?1.4 SD), which is indicative of more than 100% increased incidents of persistent depressive disorder in 4-year periods compared to average levels of PSC across 4 years.     

A scientist's viewpoint on promoting effective use of experimental design: Ten things a scientist wants to know about experimental design

This paper tackles the practical application of statistical tools. Chemical development is a rich area for collaboration between statisticians and chemists, but most statisticians encounter difficulties in promoting the tools to this client group. This paper, presented from a chemist's perspective, is intended to help bridge the gap between the two professions. The paper explores differences in uptake and attitudes towards adopting these techniques and suggests what has hindered or helped the process of effective application of experimental design. Copyright © 2003 John Wiley & Sons, Ltd.     

Geometric Ergodicity and Scanning Strategies for Two-Component Gibbs Samplers

In Markov chain Monte Carlo analysis, rapid convergence of the chain to its target distribution is crucial. A chain that converges geometrically quickly is geometrically ergodic. We explore geometric ergodicity for two-component Gibbs samplers (GS) that, under a chosen scanning strategy, evolve through one-at-a-time component-wise updates. We consider three such strategies: composition, random sequence, and random scans. We show that if any one of these scans produces a geometrically ergodic GS, so too do the others. Further, we provide a simple set of sufficient conditions for the geometric ergodicity of the GS. We illustrate our results using two examples.     

Changes in At-Risk American Men's Crime and Substance Use Trajectories Following Fatherhood

Fatherhood can be a turning point in development and in men's crime and substance use trajectories. At-risk boys (N = 206) were assessed annually from ages 12 to 31 years. Crime, arrest, and tobacco, alcohol, and marijuana use trajectories were examined. Marriage was associated with lower levels of crime and less frequent substance use. Following the birth of a first biological child, men's crime trajectories showed slope decreases, and tobacco and alcohol use trajectories showed level decreases. The older men were when they became fathers, the greater the level decreases were in crime and alcohol use and the less the slope decreases were in tobacco and marijuana use. Patterns are consistent with theories of social control and social timetables.     

Teaching social work students

The evolution of the training methods described in this paper was based on a search for relevant material, in the eyes of the student as well as the lecturer. The cornerstone of our method was to create simulations of applied situations taken from student placement experiences, and tease out both the communication elements and the central issues relating to a number of particular social work concepts. In creating explicit linkage with placement experience, the principle of student choice, in terms of identifying situations and themes appropriate for simulation, was of importance. At the same time, we would emphasize the importance of the earlier social skills and social work inputs in the course, in laying a necessary foundation for the development in the student of an ability to benefit from the broader strategy adopted in the thematic approach.     

The self as the locus of morality: A comparison between Charles Taylor and George Herbert Mead's theories of the moral constitution of the self

This paper provides a critical comparison of two leading exponents of the relationship between morality and selfhood: Charles Taylor and George Herbert Mead. Specifically, it seeks to provide an assessment of the contribution each approach is able to make to a social theory of morality that has the self at its heart. Ultimately, it is argued that Taylor's phenomenological account neglects the significance of interaction and social relations in his conceptualisation of the relationship between morality and self, which undermines the capacity of his framework to explain how moral understandings and dialogic moral subjectivity develop in a world of shared meaning. I then argue that Mead's pragmatist interactionist approach overcomes many of the flaws in Taylor's framework, and offers a grounded conceptualisation of the relationship between self and morality that is able to provide a basis for a properly social account of moral subjectivity.