Distance stability analysis in multidimensional scaling using the jackknife method

Stability or sensitivity analysis is an important topic in data analysis that has received little attention in the application of multidimensional scaling (MDS), for which the only available approaches are given in terms of a coordinate‐based analytical jackknife methodology. Although in MDS the prime interest is in assessing the stability of the points in the configuration, this methodology may be influenced by imprecisions resulting from the inherently necessary Procrustes method. This paper proposes an analytical distance‐based jackknife procedure to study stability and cross‐validation in MDS in terms of the jackknife distances, which is not influenced by the Procrustes method. For each object, the corresponding jackknife estimated points are considered as naturally clustered points, and stability and cross‐validation are analysed in terms of the MDS distances arising from the jackknife procedure, on the basis of a weighted cluster‐MDS algorithm. A jackknife‐relevant configuration is also proposed for cross‐validation in terms of coordinates, in a cluster‐MDS framework.     

Individual differences in non-clinical maternal depression impact infant affect and behavior during the still-face paradigm across the first year

Maternal depression can significantly impact mothers’ sensitivity to their infants’ needs as well as infants’ social and emotional development. The still-face paradigm (SFP) is widely used to assess infants’ understanding of the contingency between their own behavior and that of their caregivers, as well as infants’ ability to self-regulate arousal levels during sudden changes in maternal responsiveness. Infants of clinically depressed mothers display blunted levels of negative affect compared to infants of non-depressed mothers during the still-face (SF) phase. However, little is known about whether individual differences in elevated, non-clinical levels of maternal depression similarly affect mother-infant interactions. The current study examines the longitudinal effects of non-clinical maternal depression on infant and maternal behaviors during the SFP. Infants (N = 63) were assessed at 5 and 9 months and maternal depression was assessed at 5 months using the Beck Depression Inventory (BDI). Infants of mothers with elevated levels of depression displayed less negative engagement during the SF phase compared to infants of mothers with lower levels of depression. This effect was present at 5 months, but not at 9 months. Findings demonstrate that non-clinical levels of maternal depressive symptomatology can have a significant impact on infants’ affective regulation during the first half of the first year of life, but this does not necessarily have a long-lasting influence later in infancy. Interventions may want to target mothers with non-clinical depression to promote healthy infant social and emotional development.     

Preterm birth enhances the contribution of mothers’ mind-mindedness to infants’ expressive language development: A longitudinal investigation

Maternal mind-mindedness has been shown to be a powerful predictor of many developmental outcomes and to buffer the impact of psychosocial risk conditions, but no study has investigated whether this parental feature might support child development in the presence of biological risk, such as preterm birth. The present study addresses this gap, by investigating whether early maternal mind-mindedness contributes to the growth of a child’s linguistic abilities in the following two years of life, and if the contribution of this maternal feature might be stronger in the presence of preterm birth. Forty mother–child dyads (twenty with a preterm infant) were followed longitudinally, with maternal mind-mindedness assessed at 14 months of age and child’s expressive linguistic abilities at 24 and 36 months through observational measures. Multilevel models showed that linguistic abilities increased from 24 to 36 months of age, but that this increase was stronger in full-term infants. Maternal mind-mindedness also contributed to this growth, playing a stronger role in preterm infants than in full-term infants. Altogether, these findings contribute more deeply to the understanding of language development in preterm infants and of the joint contribution made by biological risk and environmental factors; from a practical standpoint, they suggest the importance of addressing mother’s mind-mindedness in order to support child’s language development.     

Childhood antecedents of Agreeableness: A longitudinal study from preschool to late adolescence

Although the consensus view is that Agreeableness originates from childhood difficultness and regulatory deficits, few studies have investigated such assumptions longitudinally. In this study, we examined this issue by assessing enduring and mediating effects of self-regulation as well as the impact of parenting behaviors on the development of Agreeableness from preschool to late adolescence. Longitudinal data from 965 Norwegian families following children from 1.5 years to 16.5 years were used. Path analyses revealed childhood difficultness at age 4 to be related to Agreeableness at age 16.5; this effect was mediated through emotion regulation in late childhood. However, such mediation effects were primarily found when parents used punitive practices towards their children. Our findings point to personality coherence throughout development.     

Neuropsychological deficits in preschool as predictors of ADHD symptoms and academic achievement in late adolescence

High levels of ADHD symptoms are related to severe negative outcomes, which underscore the importance of identifying early markers of these behavior problems. The main aim of the present study was therefore to investigate whether neuropsychological deficits in preschool are related to later ADHD symptoms and academic achievement, over and above the influence of early ADHD symptom levels. The present study is unique because it includes a broader range of predictors compared to previous studies and the participants are followed over time for as long as 13 years (i.e., ages 5–18 years). Preschool data included measures of executive functioning and reaction time variability as well as emotional reactivity and emotion regulation of both positive and negative emotions. When controlling for early ADHD symptom levels, working memory, reaction time variability, and regulation of happiness/exuberance were significantly related to inattention whereas regulation of happiness/exuberance and anger reactivity were significantly related to hyperactivity/impulsivity. Furthermore, working memory and reaction time variability in preschool were significantly related to academic achievement in late adolescence beyond the influence of early ADHD symptoms. These findings could suggest that it is possible to screen for early neuropsychological deficits and thereby identify children who are at risk of negative outcomes. Furthermore, our results suggest that interventions need to look beyond executive functioning deficits in ADHD and also target the role of emotional functioning and reaction time variability. The importance of including both the positive and negative aspects of emotional functioning and distinguishing between emotion regulation and emotional reactivity was also demonstrated.     

Managing organizational commitment: Insights from longitudinal research

This article summarizes what is known about the active management of affective organizational commitment (AOC) through a review of 58 studies employing longitudinal research designs. The review yields six broad categories of antecedents that have empirically demonstrated effects on AOC: socialization practices, organizational changes, human resource practices, interpersonal relations, employee–organizational relations, and a residual “other” category. Insights from the review include (a) that perceptions of personal attachment to the organization are among the most substantiated (but tenuous) strategies for enhancing AOC, (b) that theorizing and research efforts have focused almost exclusively on achieving high levels of AOC, and (c) organizations have been reticent to address situations when AOC is low. Implications and recommendations for the theoretical, research and practical advancement of AOC are offered.     

Risk factors for onset of eating disorders: Evidence of multiple risk pathways from an 8-year prospective study

Objective

Use classification tree analysis with lagged predictors to determine empirically derived cut-points for identifying adolescent girls at risk for future onset of threshold, subthreshold, and partial eating disorders and test for interactions between risk factors that may implicate qualitatively distinct risk pathways.

Method

Data were drawn from a prospective study of 496 adolescent girls who completed diagnostic interviews and surveys annually for 8 years.

Results

Body dissatisfaction emerged as the most potent predictor; adolescent girls in the upper 24% of body dissatisfaction showed a 4.0-fold increased incidence of eating disorder onset (24% vs. 6%). Among participants in the high body dissatisfaction branch, those in the upper 32% of depressive symptoms showed a 2.9-fold increased incidence of onset (43% vs. 15%). Among participants in the low body dissatisfaction branch, those in the upper 12% of dieting showed a 3.6-fold increased incidence onset (18% vs. 5%).

Conclusion

This three-way interaction suggests a body dissatisfaction pathway to eating disorder onset that is amplified by depressive symptoms, as well as a pathway characterized by self-reported dieting among young women who are more satisfied with their bodies. It may be possible to increase the effectiveness of prevention programs by targeting each of these qualitatively distinct risk groups, rather than only individuals with a single risk factor.     

垂直量尺化中的参数标定方法及其性能比较

在使用项目反应理论进行量尺化的语境下, 参数标定方法是垂直量尺化结果的一个至关重要的影响因素。目前的参数标定研究就部分标定方法的相对性能获得了较一致的结果, 就如何实现更佳量尺化也提出了很多新的标定方法。除了在既有框架内继续探索, 以形成完整的研究体系, 未来的研究应结合相关学科, 在深入了解学业增长的性质的基础上探究标定方法的性能, 并应考察特定的标定方法和特定的研究条件、量尺化语境之间的最佳匹配关系。     

Infants in group care: their interactions with professional caregivers and parents across the second year of life

Seventy children were observed during structured play with their primary professional caregivers and three peers in the child care center and with their primary caregiving parents at home at 15 and 23 months of age. The same structured play tasks were used in the two settings and the quality of the children's interactions with caregivers and parents was rated using the same 7-point scales. As expected, the quality of caregiver–child interactions significantly increased between 15 and 23 months. At 15 months, the quality of caregiver–child interactions was significantly lower than the quality of parent–child interactions, particularly with regard to caregiver supportive presence and respect for the child's autonomy. At 23 months, however, the quality of caregiver–child interactions was no longer lower and in some respects even higher than the quality of parent–child interactions. At both ages, the children expressed more negativity towards their parents than towards their professional caregivers.     

Academic Achievement Over 8 Years Among Children Who Met Modified Criteria for Attention-deficit/Hyperactivity Disorder at 4–6 Years of Age

The predictive validity of symptom criteria for different subtypes of ADHD among children who were impaired in at least one setting in early childhood was examined. Academic achievement was assessed seven times over 8 years in 125 children who met symptom criteria for ADHD at 4–6 years of age and in 130 demographically-matched non-referred comparison children. When intelligence and other confounds were controlled, children who met modified criteria for the predominantly inattentive subtype of ADHD in wave 1 had lower reading, spelling, and mathematics scores over time than both comparison children and children who met modified criteria for the other subtypes of ADHD. In some analyses, children who met modified criteria for the combined type had somewhat lower mathematics scores than comparison children. The robust academic deficits relative to intelligence in the inattentive group in this age range suggest either that inattention results in academic underachievement or that some children in the inattentive group have learning disabilities that cause secondary symptoms of inattention. Unexpectedly, wave 1 internalizing (anxiety and depression) symptoms independently predicted deficits in academic achievement controlling ADHD, intelligence, and other predictors.