Commentary: Using Potential Outcomes to Understand Causal Mediation Analysis

In this commentary, we demonstrate how the potential outcomes framework can help understand the key identification assumptions underlying causal mediation analysis. We show that this framework can lead to the development of alternative research design and statistical analysis strategies applicable to the longitudinal data settings considered by Maxwell, Cole, and Mitchell (2011).     

Bias in Cross-Sectional Analyses of Longitudinal Mediation: Partial and Complete Mediation Under an Autoregressive Model

Maxwell and Cole (2007) Maxwell, S. E. and Cole, D. A. 2007. Bias in cross-sectional analyses of longitudinal mediation. Psychological Methods, 12: 23–44. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar] showed that cross-sectional approaches to mediation typically generate substantially biased estimates of longitudinal parameters in the special case of complete mediation. However, their results did not apply to the more typical case of partial mediation. We extend their previous work by showing that substantial bias can also occur with partial mediation. In particular, cross-sectional analyses can imply the existence of a substantial indirect effect even when the true longitudinal indirect effect is zero. Thus, a variable that is found to be a strong mediator in a cross-sectional analysis may not be a mediator at all in a longitudinal analysis. In addition, we show that very different combinations of longitudinal parameter values can lead to essentially identical cross-sectional correlations, raising serious questions about the interpretability of cross-sectional mediation data. More generally, researchers are encouraged to consider a wide variety of possible mediation models beyond simple cross-sectional models, including but not restricted to autoregressive models of change.     

Correlational Data,Causal Hypotheses,and Validity

A shared problem across the sciences is to make sense of correlational data coming from observations and/or from experiments. Arguably, this means establishing when correlations are causal and when they are not. This is an old problem in philosophy. This paper, narrowing down the scope to quantitative causal analysis in social science, reformulates the problem in terms of the validity of statistical models. Two strategies to make sense of correlational data are presented: first, a ‘structural strategy’, the goal of which is to model and test causal structures that explain correlational data; second, a ‘manipulationist or interventionist strategy’, that hinges upon the notion of invariance under intervention. It is argued that while the former can offer a solution the latter cannot.     

Methods for Mediation Analysis with Missing Data

Despite wide applications of both mediation models and missing data techniques, formal discussion of mediation analysis with missing data is still rare. We introduce and compare four approaches to dealing with missing data in mediation analysis including listwise deletion, pairwise deletion, multiple imputation (MI), and a two-stage maximum likelihood (TS-ML) method. An R package bmem is developed to implement the four methods for mediation analysis with missing data in the structural equation modeling framework, and two real examples are used to illustrate the application of the four methods. The four methods are evaluated and compared under MCAR, MAR, and MNAR missing data mechanisms through simulation studies. Both MI and TS-ML perform well for MCAR and MAR data regardless of the inclusion of auxiliary variables and for AV-MNAR data with auxiliary variables. Although listwise deletion and pairwise deletion have low power and large parameter estimation bias in many studied conditions, they may provide useful information for exploring missing mechanisms.     

A Comparison of the Cross-Sectional and Sequential Designs when Assessing Longitudinal Mediation

Mediational studies are often of interest in psychology because they explore the underlying relationship between 2 constructs. Previous research has shown that cross-sectional designs are prone to biased estimates of longitudinal mediation parameters. The sequential design has become a popular alternative to the cross-sectional design for assessing mediation. This design is a compromise between the cross-sectional and longitudinal designs because it incorporates time in the model but has only 1 measurement each of X, M, and Y. As such, this design follows the recommendation of the MacArthur group approach, which stresses the importance of multiple waves of data for studying mediation. These 2 designs were compared to see whether the sequential design assesses longitudinal mediation more accurately than the cross-sectional design. Specifically, analytic expressions are derived for the bias of estimated direct and indirect effects as calculated from the sequential design when the actual mediational process follows a longitudinal autoregressive model. It was found that, in general, the sequential design does not assess longitudinal mediation more accurately than the cross-sectional design. As a result, neither design can be depended on to assess longitudinal mediation accurately.     

Sociosexual Orientation,Commitment, and Infidelity: A Mediation Analysis

ABSTRACT

Individuals with an unrestricted sociosexual orientation (SO) are less committed to their romantic relationships and more likely to engage in infidelity. Furthermore, commitment is negatively associated with tendencies to cheat. However, no previous research has examined the possible mediating role of commitment in the relationship between SO and infidelity. The current study examined whether commitment mediated the relationship between SO and willingness to engage in three types of cheating behaviors (Ambiguous, Deceptive, and Explicit). Results suggested that commitment partially mediated the relationship between SO and infidelity, such that unrestricted individuals had lower commitment, which in turn led to a greater likelihood of cheating. Implications of this association and directions for future research are discussed.     

Identification and Sensitivity Analysis for Average Causal Mediation Effects with Time-Varying Treatments and Mediators: Investigating the Underlying Mechanisms of Kindergarten Retention Policy

Considering that causal mechanisms unfold over time, it is important to investigate the mechanisms over time, taking into account the time-varying features of treatments and mediators. However, identification of the average causal mediation effect in the presence of time-varying treatments and mediators is often complicated by time-varying confounding. This article aims to provide a novel approach to uncovering causal mechanisms in time-varying treatments and mediators in the presence of time-varying confounding. We provide different strategies for identification and sensitivity analysis under homogeneous and heterogeneous effects. Homogeneous effects are those in which each individual experiences the same effect, and heterogeneous effects are those in which the effects vary over individuals. Most importantly, we provide an alternative definition of average causal mediation effects that evaluates a partial mediation effect; the effect that is mediated by paths other than through an intermediate confounding variable. We argue that this alternative definition allows us to better assess at least a part of the mediated effect and provides meaningful and unique interpretations. A case study using ECLS-K data that evaluates kindergarten retention policy is offered to illustrate our proposed approach.     

Causal Closure,Causal Exclusion,and Supervenience Physicalism

This article considers the recent defense of the supervenience approach to physicalism due to Jaegwon Kim. Kim argues that supervenience supports physical causal closure, and that causal closure supports physicalism – indeed, a kind of reductive physicalism – and thus that supervenience suffices for physicalism. After laying out Kim's argument, I ask whether its success would truly vindicate the role of supervenience in defining physicalist positions. I argue that it would not, and that insofar as Kim's defense of supervenience physicalism succeeds, it does so by showing that supervenience physicalism is not a unique, nonredundant way to be a physicalist.     

Well-Being and Physical Health: A Mediation Analysis

This paper’s aim is to propose a mediation framework and test whether lifestyle choices and social capital are pathways through which baseline levels of well-being affect subsequent physical health among older adults. Using large-scale panel data for Australia, we find that past levels of well-being have strong direct effects on present physical health. We also show that more frequent socialization and more frequent participation in physical activity are two pathways through which higher levels of well-being lead to better physical health. These mediating effects vary across gender. Our findings highlight a protective role of subjective well-being in physical health. Interventions taking into account not only the direct but also the indirect effects of well-being are promising avenues for physical health maintenance in the older population.

     

Understanding How Creative Thinking Skills,Attitudes and Behaviors Work Together: A Causal Process Model

Managers (N = 112) from a large international consumer goods manufacturer participated in a field experiment in which they learned and applied the Simplex process of creative thinking to solve real management problems. The interrelationships among six attitudinal and behavioral skill variables learned during the training were measured to improve understanding of how these variables contribute to the process. Predicted relationships were tested and a best‐fit causal model was developed. Behavioral skill in generating quantity of options was the most important variable overall: it was directly associated with behavioral skill in both generating quality options and evaluating options. The key attitudinal skill and the second most important variable overall was the preference for avoiding premature evaluation of options (deferral of judgment). The other attitude measured, the preference for active divergence, played only an indirect role in the process.     

Personality,Positivity and Happiness: A Mediation Analysis Using a Bifactor Model

Recent studies suggested an important role of neuroticism and extraversion facets as incremental predictors of subjective well-being outcomes. Research has shown that positive cognitions mediated the relation between personality traits and well-being. The present study examined the relationship between neuroticism and extraversion, measured as general and group factors, and subjective happiness through a general positivity factor. 770 community participants (69.4 % females; M = 55.34; SD = 16.01) completed personality, satisfaction with life, optimism, self-esteem, and subjective happiness scales. A bifactor model was used to parse general and specific variance components for multifaceted constructs. The general positivity factor completely mediated neuroticism-subjective happiness relationships and overlapped with general neuroticism, whilst it partially mediated extraversion-subjective happiness ones. Other paths to happiness involved cheerfulness and enthusiasm. Assertiveness, activity level and excitement-seeking had a weak relationship with subjective happiness and only through positivity. Gregariousness and friendliness had neither direct nor indirect effects on subjective happiness. Life satisfaction had a twofold role as a component of positivity as well as providing an independent contribution to variance in subjective happiness. In keeping with previous research, neuroticism acted as a sort of general negativity factor. Cheerfulness and extraversion made an incremental contribution to variance in subjective happiness. Our findings support the utility of a multifaceted approach to study pathways from personality to well-being. Theoretical and practical implications for promoting well-being were discussed.     

Maladaptive Parenting,Temperament, Early Maladaptive Schemas,and Depression: A Moderated Mediation Analysis

According to the Schema Therapy Model, maladaptive parenting styles interact with a child’s unique temperament in the development of early maladaptive schemas (EMSs), which in turn increase one’s risk for developing pathology. However, few authors have examined the comprehensive model. The purpose of this study was to assess the indirect effect of perceived parenting styles on depressive symptoms through EMSs. Furthermore, a series of moderated mediation analyses were conducted to examine whether the indirect effect varies as a function of temperament. A total of 403 undergraduate students completed measures of perceived parenting experiences, temperament, EMSs, and depressive symptoms. Results indicated that the schema domains of disconnection/rejection and impaired autonomy mediated the relationship between perceived parenting styles and depressive symptoms. Moderation of the indirect effect was only found in two of the twelve tested models. This study lends partial support to the Schema Therapy model and also offers a new way of looking at the interactive nature of the constructs.     

Flexible Mediation Analysis in the Presence of Nonlinear Relations: Beyond the Mediation Formula

In the social sciences, mediation analysis has typically been formulated in the context of linear models using the Baron &; Kenny (1986) Baron, R. M. and Kenny, D. A. 1986. The moderator-mediator variable distinction in social psychological research: Conceptual, strategic and statistical considerations. Journal of Personality and Social Psychology, 51: 1173–1182. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar] approach. Extensions to nonlinear models have been considered but lack formal justification. By placing mediation analysis within the counterfactual framework of causal inference one can define causal mediation effects in a way that is not tied to a specific statistical model and identify them under certain no unmeasured confounding assumptions. Corresponding estimation procedures using parametric or nonparametric models, based on the so-called mediation formula, have recently been proposed in the psychological literature and made accessible through the R-package mediation. A number of limitations of the latter approach are discussed and a more flexible approach using natural effects models is proposed as an alternative. The latter builds on the same counterfactual framework but enables interpretable and parsimonious modeling of direct and mediated effects and facilitates tests of hypotheses that would otherwise be difficult or impossible to test. We illustrate the approach in a study of individuals who ended a romantic relationship and explore whether the effect of attachment anxiety during the relationship on unwanted pursuit behavior after the breakup is mediated by negative affect during the breakup.     

Age-Related Differences in Identity Style: A Cross-Sectional Analysis

The Identity Style Inventory–Revised for a Sixth-Grade Reading Level (ISI-6G) was administered to samples of community college students (N = 99) and middle school and high school students (N = 320). Tests of between-groups differences indicated that the college sample had a significantly lower mean diffuse-avoidant score on the ISI-6G than the middle and high school sample. In terms of actual assignment to identity styles, college students were significantly more likely to be classified as informational or normative, while the younger students were more likely to be diffuse-avoidant. The mean ages of participants for each of the three identity styles were compared, and it was found that diffuse-avoidant participants had the lowest mean age (15.54 years), while individuals with an informational orientation had the highest mean age (17.20 years). Results suggest that, in general, identity style evolves with age and maturity and the general trajectory or progression involves movement away from a diffuse-avoidant orientation. Findings are discussed in terms of current knowledge of neurocognitive development during adolescence and early adulthood.     

Household Happiness and Fuel Poverty: a Cross-Sectional Analysis on Turkey

Applied Research in Quality of Life - In recent years, self-reported happiness and fuel poverty have both become hotly-debated topics in the literature. Since both of them affect people’s...     

Demands of Justice, Feasible Alternatives, and the Need for Causal Analysis

Many political philosophers hold the Feasible Alternatives Principle (FAP): justice demands that we implement some reform of international institutions P only if P is feasible and P improves upon the status quo from the standpoint of justice. The FAP implies that any argument for a moral requirement to implement P must incorporate claims whose content pertains to the causal processes that explain the current state of affairs. Yet, philosophers routinely neglect the need to attend to actual causal processes. This undermines their arguments concerning moral requirements to reform international institutions. The upshot is that philosophers’ arguments must engage in causal analysis to a greater extent than is typical.     

时间管理倾向与自尊、自我效能、学习满意度:中介作用分析

探讨时间管理效能对时间监控行为和自尊、自我效能和学习满意度的中介作用。随机选取260名大学生为研究对象。结果表明时间管理效能对时间监控行为和自尊、自我效能和学习满意度具有部分中介作用,也就是时间监控行为既可以通过时间管理效能来影响自尊、自我效能和学习满意度,也可以直接影响自我效能和学习满意度。