Biomedical subjects

Kristopher J Preacher

Publications and source records attributed to Kristopher J Preacher.

9 recordsLinked to original sources

PubMed2006

Parental verbal abuse and the mediating role of self-criticism in adult internalizing disorders.

BACKGROUND: Researchers (e.g., [Gibb, B.E., 2002. Childhood maltreatment and negative cognitive styles. A quantitative and qualitative review. Clinical Psychology Review, 22 (2), 223-246]; [Rose, D.T., Abramson, L.Y., 1992. Developmental predictors of depressive cognitive styles: developmental perspectives on depression. In Cicchetti, D., Toth, S.L. (Eds.), Developmental Perspectives on Depression. Rochester symposium on developmental psychopathology, vol. 4, pp. 323-349]) have proposed that when childhood abuse is verbal (rather than sexual or physical), the child is more likely to develop a negative self-schema because the negative self-cognitions are directly supplied to the child by the abuser (e.g., "you are stupid"). METHODS: In a test of this theory in adult participants, and drawing on the National Comorbidity Survey (NCS) (N=5877), we investigate the mediating role of current levels of self-criticism on the relationship between retrospective reports of parental verbal abuse, as well as sexual and physical abuse, and adult internalizing symptoms. RESULTS: We found self-criticism, but not dependency traits, to fully mediate the relationship between childhood verbal abuse perpetrated by parents and internalizing (depression, anxiety) symptoms. On the other hand, self-criticism was only a partial mediator of the relationship between the other types of abuse and internalizing symptoms. LIMITATIONS: The NCS data is cross-sectional, which limits any firm conclusions regarding causality. While these results are suggestive that self-criticism is a mediator of the relationship between abuse and internalizing symptoms, longitudinal data are necessary to help rule out alternative explanations. CONCLUSIONS: Results of this study suggest that childhood abuse experiences, and in particular verbal abuse, may confer risk for internalizing disorders in part because verbal abuse influences the development of a self-critical style.

Adolescent↗

PubMed2006

Conceptualizing and testing random indirect effects and moderated mediation in multilevel models: new procedures and recommendations.

The authors propose new procedures for evaluating direct, indirect, and total effects in multilevel models when all relevant variables are measured at Level 1 and all effects are random. Formulas are provided for the mean and variance of the indirect and total effects and for the sampling variances of the average indirect and total effects. Simulations show that the estimates are unbiased under most conditions. Confidence intervals based on a normal approximation or a simulated sampling distribution perform well when the random effects are normally distributed but less so when they are nonnormally distributed. These methods are further developed to address hypotheses of moderated mediation in the multilevel context. An example demonstrates the feasibility and usefulness of the proposed methods.

Adolescent↗

PubMed2005

Coping with stereotype threat: denial as an impression management strategy.

Four experiments tested the hypothesis that people who are concerned with impression management cope with stereotype threat through denial. Consistent with this hypothesis, temporary employees threatened by a stereotype of incompetence (Study 1) and hostel-dwelling older adults (Study 2) were more likely to deny incompetence if they were high in impression management. African Americans (Study 3) showed a similar pattern of denying cognitive incompetence, which emerged primarily when they were interviewed by a White experimenter and had attended a predominantly Black high school. In Study 4, White students who expected to take an IQ test and were threatened by a stereotype of being less intelligent than Asians were more likely to deny that intelligence is important if they were high in impression management.

Adaptation, Psychological↗

PubMed2005

Use of the extreme groups approach: a critical reexamination and new recommendations.

Analysis of continuous variables sometimes proceeds by selecting individuals on the basis of extreme scores of a sample distribution and submitting only those extreme scores to further analysis. This sampling method is known as the extreme groups approach (EGA). EGA is often used to achieve greater statistical power in subsequent hypothesis tests. However, there are several largely unrecognized costs associated with EGA that must be considered. The authors illustrate the effects EGA can have on power, standardized effect size, reliability, model specification, and the interpretability of results. Finally, the authors discuss alternative procedures, as well as possible legitimate uses of EGA. The authors urge researchers, editors, reviewers, and consumers to carefully assess the extent to which EGA is an appropriate tool in their own research and in that of others.

Group Processes↗

PubMed2004

SPSS and SAS procedures for estimating indirect effects in simple mediation models.

Researchers often conduct mediation analysis in order to indirectly assess the effect of a proposed cause on some outcome through a proposed mediator. The utility of mediation analysis stems from its ability to go beyond the merely descriptive to a more functional understanding of the relationships among variables. A necessary component of mediation is a statistically and practically significant indirect effect. Although mediation hypotheses are frequently explored in psychological research, formal significance tests of indirect effects are rarely conducted. After a brief overview of mediation, we argue the importance of directly testing the significance of indirect effects and provide SPSS and SAS macros that facilitate estimation of the indirect effect with a normal theory approach and a bootstrap approach to obtaining confidence intervals, as well as the traditional approach advocated by Baron and Kenny (1986). We hope that this discussion and the macros will enhance the frequency of formal mediation tests in the psychology literature. Electronic copies of these macros may be downloaded from the Psychonomic Society's Web archive at www.psychonomic.org/archive/.

Humans↗

PubMed2003

Chronic stress and age-related increases in the proinflammatory cytokine IL-6.

Overproduction of IL-6, a proinflammatory cytokine, is associated with a spectrum of age-related conditions including cardiovascular disease, osteoporosis, arthritis, type 2 diabetes, certain cancers, periodontal disease, frailty, and functional decline. To describe the pattern of change in IL-6 over 6 years among older adults undergoing a chronic stressor, this longitudinal community study assessed the relationship between chronic stress and IL-6 production in 119 men and women who were caregiving for a spouse with dementia and 106 noncaregivers, with a mean age at study entry of 70.58 (SD = 8.03) for the full sample. On entry into this portion of the longitudinal study, 28 of the caregivers' spouses had already died, and an additional 50 of the 119 spouses died during the 6 years of this study. Levels of IL-6 and health behaviors associated with IL-6 were measured across 6 years. Caregivers' average rate of increase in IL-6 was about four times as large as that of noncaregivers. Moreover, the mean annual changes in IL-6 among former caregivers did not differ from that of current caregivers even several years after the death of the impaired spouse. There were no systematic group differences in chronic health problems, medications, or health-relevant behaviors that might have accounted for caregivers' steeper IL-6 slope. These data provide evidence of a key mechanism through which chronic stressors may accelerate risk of a host of age-related diseases by prematurely aging the immune response.

Aged↗

PubMed2002

Exploratory factor analysis in behavior genetics research: factor recovery with small sample sizes.

Results of a Monte Carlo study of exploratory factor analysis demonstrate that in studies characterized by low sample sizes the population factor structure can be adequately recovered if communalities are high, model error is low, and few factors are retained. These are conditions likely to be encountered in behavior genetics research involving mean scores obtained from sets of inbred strains. Such studies are often characterized by a large number of measured variables relative to the number of strains used, highly reliable data, and high levels of communality. This combination of characteristics has special consequences for conducting factor analysis and interpreting results. Given that limitations on sample size are often unavoidable, it is recommended that researchers limit the number of expected factors as much as possible.

Animals↗

PubMed2002

On the practice of dichotomization of quantitative variables.

The authors examine the practice of dichotomization of quantitative measures, wherein relationships among variables are examined after 1 or more variables have been converted to dichotomous variables by splitting the sample at some point on the scale(s) of measurement. A common form of dichotomization is the median split, where the independent variable is split at the median to form high and low groups, which are then compared with respect to their means on the dependent variable. The consequences of dichotomization for measurement and statistical analyses are illustrated and discussed. The use of dichotomization in practice is described, and justifications that are offered for such usage are examined. The authors present the case that dichotomization is rarely defensible and often will yield misleading results.

Humans↗

PubMed2002

Comments on the Meehl-Waller (2002) procedure for appraisal of path analysis models.

P. E. Meehl and N. G. Waller (2002) proposed an innovative method for assessing path analysis models wherein they subjected a given model, along with a set of alternatives, to risky tests using selected elements of a sample correlation matrix. Although the authors find much common ground with the perspective underlying the Meehl-Waller approach, they suggest that there are aspects of the proposed procedure that require close examination and further development. These include the selection of only one subset of correlations to estimate parameters when multiple solutions are generally available, the fact that the risky tests may test only a subset of parameters rather than the full model of interest, and the potential for different results to be obtained from analysis of equivalent models.

Humans↗