Longitudinal Dynamics of Substance Use and Psychiatric Symptoms in Count Data with Zero Inflation

We examine the dynamics of substance use and psychiatric symptoms from childhood to adolescence using a longitudinal study of Mexican-origin families (N = 674). We present a longitudinal model capturing the trajectories of substance use and psychiatric symptoms (depression, conduct disorder), as well as the interrelations between these trajectories over time. Such a model is an extension of latent change score models designed to account for the occurrence of psychiatric symptoms while also accommodating a large amount of zeros for nonoccurrence and characterizing the changes over time in the count data. We compare this model with a more traditional approach based on a log transformation of the data. We describe differences between these approaches and highlight the benefits of using the two-part model when the data include a large amount of zeros for nonoccurrence of the behavior.     

Dispositional optimism: a psychological resource for Mexican-origin mothers experiencing economic stress

Dispositional optimism is believed to be an important psychological resource that buffers families against the deleterious consequences of economic adversity. Using data from a longitudinal study of Mexican-origin families (N = 674), we tested a family stress model specifying that maternal dispositional optimism and economic pressure affect maternal internalizing symptoms, which, in turn, affects parenting behaviors and children's social adjustment. As predicted, maternal optimism and economic pressure had both independent and interactive effects on maternal internalizing symptoms, and the effects of these variables on changes over time in child social adjustment were mediated by nurturant and involved parenting. The findings replicate and extend previous research on single-parent African American families (Taylor, Larsen-Rife, Conger, Widaman, & Cutrona, 2010), and demonstrate the generalizability of the positive benefits of dispositional optimism in another ethnic group and type of family structure.     

The Rabkin Test as a Means of Detecting and Analyzing Defective Color Vision

This study investigated the attentional and mental-set conditions which determine the acquisition and use of memory schema cues. Ninety male and female undergraduate Ss listened to and shadowed the Bransford-Johnson “washing clothes” paragraph under a variety of conditions defined by cue placement (before or during shadowing), attentional mental set (told of relation of cue to passage, or not told), and modality of cue (given visually or auditorily). It was found that cue placement and cue modality had no effect on subsequent recall of the passage, but that attentional mental set did. It was argued that the data supported a model of the mind that emphasized conscious intention in both attention and schema activation, a position associated with Wilhelm Wundt.     

A comparison of two‐stage procedures for testing least‐squares coefficients under heteroscedasticity

This study explores the performance of several two‐stage procedures for testing ordinary least‐squares (OLS) coefficients under heteroscedasticity. A test of the usual homoscedasticity assumption is carried out in the first stage of the procedure. Subsequently, a test of the regression coefficients is chosen and performed in the second stage. Three recently developed methods for detecting heteroscedasticity are examined. In addition, three heteroscedastic robust tests of OLS coefficients are considered. A major finding is that performing a test of heteroscedasticity prior to applying a heteroscedastic robust test can lead to poor control over Type I errors.     

The importance of a visual horizon for distance judgments under severely degraded vision

In two experiments we examined the role of visual horizon information on absolute egocentric distance judgments to on-ground targets. Sedgwick [1983, in Human and Machine Vision (New York: Academic Press) pp 425-458] suggested that the visual system may utilize the angle of declination from a horizontal line of sight to the target location (horizon distance relation) to determine absolute distances on infinite ground surfaces. While studies have supported this hypothesis, less is known about the specific cues (vestibular, visual) used to determine horizontal line of sight. We investigated this question by requiring observers to judge distances under degraded vision given an unaltered or raised visual horizon. The results suggest that visual horizon information does influence perception of absolute distances as evident through two different action-based measures: walking or throwing without vision to previously viewed targets. Distances were judged as shorter in the presence of a raised visual horizon. The results are discussed with respect to how the visual system accurately determines absolute distance to objects on a finite ground plane and for their implications for understanding space perception in low-vision individuals.     

Comparing the regression slopes of independent groups

In this study, we explore the effects of non‐normality and heteroscedasticity when testing the hypothesis that regression lines associated with two independent groups have the same slopes. Our results indicate that some recently proposed methods that allow heteroscedasticity and perform well in extant simulation studies do not perform well for the situation at hand. Two of the methods studied here are recommended for general use.     

Family and individual difference predictors of trait aspects of negative interpersonal behaviors during emerging adulthood.

A latent trait-state-occasion (TSO) model (D. A. Cole, N. C. Martin, & J. H. Steiger, 2005) was used to isolate the trait and state components of negative interpersonal behaviors toward a friend or romantic partner during emerging adulthood. Results indicate that variance in negative interpersonal behaviors was due to nearly equal portions of Trait and Occasion factors. Variability in the trait aspects of negative interpersonal behaviors was then predicted by theoretically relevant constructs. In particular, mothers' negative behaviors during adolescence, adolescent core self-evaluations, negative emotionality, and feelings of security in close relationships had independent effects in predicting the enduring aspects of negative interpersonal behaviors. All told, these results indicate that TSO models can be helpful tools for understanding the developmental antecedents of the trait-like aspects of interpersonal processes.     

A comparative study of robust tests for spread: Asymmetric trimming strategies

We examined 633 procedures that can be used to compare the variability of scores across independent groups. The procedures, except for one, were modifications of the procedures suggested by Levene (1960) and O'Brien (1981). We modified their procedures by substituting robust measures of the typical score and variability, rather than relying on classical estimators. The robust measures that we utilized were either based on a priori or empirically determined symmetric or asymmetric trimming strategies. The Levene‐type and O'Brien‐type transformed scores were used with either the ANOVA F test, a robust test due to Lee and Fung (1985), or the Welch (1951) test. Based on four measures of robustness, we recommend a Levene‐type transformation based upon empirically determined 20% asymmetric trimmed means, involving a particular adaptive estimator, where the transformed scores are then used with the ANOVA F test.