Thomas Ledermann

Estimating, testing, and comparing specific effects in structural equation models: The phantom model approach.

The phantom model approach for estimating, testing, and comparing specific effects within structural equation models (SEMs) is presented. The rationale underlying this novel method consists in representing the specific effect to be assessed as a total effect within a separate latent variable model, the phantom model that is added to the main model. The following favorable features characterize the method: (a) It enables the estimation, testing, and comparison of arbitrary specific effects for recursive and nonrecursive models with latent and manifest variables; (b) it enables the bootstrapping of confidence intervals; and (c) it can be applied with all standard SEM programs permitting latent variables, the specification of equality constraints, and the bootstrapping of total effects. These features along with the fact that no manipulation of matrices and formulas is required make the approach particularly suitable for applied researchers. The method is illustrated by means of 3 examples with real data sets.

Assessing Mediation in Dyadic Data Using the Actor-Partner Interdependence Model

The assessment of mediation in dyadic data is an important issue if researchers are to test process models. Using an extended version of the actor–partner interdependence model the estimation and testing of mediation is complex, especially when dyad members are distinguishable (e.g., heterosexual couples). We show how the complexity of the model can be reduced by assuming specific dyadic patterns. Using structural equation modeling, we demonstrate how specific mediating effects and contrasts among effects can be tested by phantom models that permit point and bootstrap interval estimates. We illustrate the assessment of mediation and the strategies to simplify the model using data from heterosexual couples.

Detecting, Measuring, and Testing Dyadic Patterns in the Actor―Partner Interdependence Model

Family researchers have used the actor-partner interdependence model (APIM) to study romantic couples, parent-child dyads, and siblings. We discuss a new method to detect, measure, and test different theoretically important patterns in the APIM: equal actor and partner effect (couple pattern); same size, but different signs of actor and partner effects (contrast pattern); and zero partner effects (actor-only pattern). To measure these different patterns, as well as others, we propose the estimation of the parameter k, which equals the partner effect divided by the actor effect. For both indistinguishable dyad members (e.g., twins) and distinguishable dyad members (e.g., heterosexual couples), we propose strategies for estimating and testing different models. We illustrate our new approach with four data sets.

Associations among everyday stress, critical life events, and sexual problems

This study addresses the question of how stress is linked to sexual problems among women and men in close relationships. Psychological symptoms, relationship quality, internal daily stress (i.e., originating within the couple such as conflicts, worry for the partner), external daily stress (i.e., stress arising outside the couple such as job stress, stressful relatives, and so forth), and critical life events were examined with regard to their association with different sexual problems. The results support the hypotheses that (1) there is an incremental effect of stress on sexual problems after controlling for psychological symptoms and relationship quality, and that (2) it is primarily internal daily stress and in some cases critical life events rather than external daily stress that are related to sexual problems, particularly hypoactive sexual desire in women and men, sexual aversion in women, vaginismus in women, and premature ejaculation in men. Our findings indicate that the treatment of these sexual problems should address relationship issues and include a focus on helping individuals improve their stress management skills within their couple relationship.

The Common Fate Model for Dyadic Data: Variations of a Theoretically Important but Underutilized Model

Studying dyads, very often there is a theoretical construct that has an effect on both members, such as relationship harmony or shared environment. To model such influences, the common fate model (CFM) is often the most appropriate approach. In this article, we address conceptual and statistical issues in the use of the standard CFM and present a series of variations, all of which are estimated by structural equation modeling (SEM). For indistinguishable dyad members (e.g., gay couples), we describe the use of a multilevel SEM method. Throughout the paper, we draw connections to the actor-partner interdependence model (APIM). We also discuss the analysis of hybrid models that combines both the CFM and the APIM. The models are illustrated using data from heterosexual couples.

Variability of Sleep Duration Is Related to Subjective Sleep Quality and Subjective Well-Being: An Actigraphy Study

While there is a large body of evidence that poor subjective sleep quality is related to lower subjective well-being, studies on the relation of objective sleep measures and subjective well-being are fewer in number and less consistent in their findings. Using data of the Survey of Mid-Life in the United States (MIDUS), we investigated whether duration and quality of sleep, assessed by actigraphy, were related to subjective well-being and whether this relationship was mediated by subjective sleep quality. Three hundred and thirteen mainly white American individuals from the general population and 128 urban-dwelling African American individuals between 35 and 85 years of age were studied cross-sectionally. Sleep duration, variability of sleep duration, sleep onset latency, and time awake after sleep onset were assessed by actigraphy over a period of 7 days. Subjective sleep quality was assessed with the Pittsburgh Sleep Quality Index, positive psychological well-being and symptoms of psychological distress were assessed with the Satisfaction with Life Scale and the Mood and Anxiety Symptom Questionnaire. In both white and African Americans high day-to-day variability in sleep duration was related to lower levels of subjective well-being controlling age, gender, educational and marital status, and BMI. By contrast, sleep duration, sleep onset latency, and time awake after sleep onset were not related to subjective well-being controlling covariates and other sleep variables. Moreover, the relationship between variability in sleep duration and well-being was partially mediated by subjective sleep quality. The findings show that great day-to-day variability in sleep duration – more than average sleep duration – is related to poor subjective sleep quality and poor subjective well-being.

Stress, anger, and verbal aggression in intimate relationships: Moderating effects of individual and dyadic coping

Verbally aggressive exchanges between intimate partners are more likely during times of stress. Therefore, the present study examines (i) whether partners’ proneness to anger mediates the association between stress and verbal aggression and (ii) the degree to which individual and dyadic coping moderate associations among stress, anger, and aggression. Effective individual and dyadic coping reduces the effects of stress on aggression. Moreover, dyadic coping may attenuate associations between stress and both anger and verbal aggression. Individuals reporting adaptive and maladaptive coping typically differed in verbal aggression when stress was low, but not when stress was high. This is consistent with the notion that stressors govern strong negative emotion displayed in marriage. Implications of these findings for interventions that mitigate the effects of stress on relationships are discussed.

Moderator- und Mediatoreffekte bei dyadischen Daten

Zusammenfassung: Zur Analyse von Moderator- und Mediatoreffekten bei dyadischen Daten werden zwei Erweiterungen des Akteur-Partner-Interdependenz-Modells (z. B. Kenny, 1996) vorgestellt. Die Modelle, die als Akteur-Partner-Moderator-Modell und Akteur-Partner-Mediator-Modell bezeichnet werden, dienen im Rahmen von dyadischen Untersuchungen der Uberprufung von Drittvariablen, welche die Zusammenhange zwischen abhangigen und unabhangigen Variablen moderieren bzw. mediieren. Neben einer Anleitung zur Analyse des Moderatormodells mittels Regressionsanalysen finden sich Hinweise zur Durchfuhrung von Bootstrap-Analysen bei Verwendung von Strukturgleichungsanalysen. Zur Einschatzung der Mediation werden verschiedene Indikatoren erortert. Beide Modelle werden anhand von Daten zu Alltagsstress, Partnerschaftsqualitat, Depressivitat und sexuellen Storungen bei 198 Paaren illustriert. Die zum Akteur-Partner-Moderator-Modell durchgefuhrten Regressions- und Bootstrap-Analysen stutzen die Hypothese, dass der Zusammenhan...

Analyzing Dyadic Data With Multilevel Modeling Versus Structural Equation Modeling: A Tale of Two Methods

Multilevel modeling (MLM) and structural equation modeling (SEM) are the dominant methods for the analysis of dyadic data. Both methods are extensively reviewed for the widely used actor–partner interdependence model and the dyadic growth curve model, as well as other less frequently adopted models, including the common fate model and the mutual influence model. For each method, we discuss the analysis of distinguishable and indistinguishable members, the treatment of missing data, the standardization of effects, and tests of mediation. Even though there has been some blending of the 2 methods, each method has its own advantages and disadvantages, thus both should be in the toolbox of dyadic researchers.

The role of power in intimate relationships

The current study examined relationship power in the context of the investment model of relationship commitment (Rusbult, 1980). It was hypothesized that satisfaction with, quality of alternatives to, and investment in the relationship would mediate the relationship between power and commitment in 120 dating couples. Data were analyzed using mediation within the actor-partner interdependence model. Participants who possessed a higher level of power reported lower satisfaction and commitment and higher quality of alternatives. Furthermore, the relationship between female’s power and male’s commitment was mediated by male’s satisfaction and the relationship between male’s power and female’s commitment was mediated by male’s quality of alternatives. Findings are discussed within the context of the field’s expanding conceptualization of power within intimate relationships.