CONTEXT: Early language development supports cognitive, academic, and behavioral success. Identifying modifiable predictors of child language may inform policies and practices aiming to promote language development. OBJECTIVE: To synthesize results of observational studies examining parenting behavior and early childhood language in typically developing samples.

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Adverse life events are associated with a constellation of negative health outcomes. Theory and research suggest that the hypothalamic-pituitary-adrenal (HPA) axis acts as one mechanism connecting adverse experiences with negative health outcomes. However, this relation is complicated by the potential for adversity to be associated with both hyperactivity and hypoactivity of the HPA axis, as assessed in both animal and human studies. Over the past decade, methodological advances have enabled the sampling of cortisol stored in hair, which provides a marker of HPA axis activity over a several-month period. The present meta-analysis included 28 studies to assess the strength and direction of the relation between adverse experiences and hair cortisol levels. Analyses were conducted using multilevel modeling (MLM) to quantify the magnitude of effects and mixture modeling to identify distinct subgroups of studies. Results of MLM analyses indicated that the overall effect size was small but significant d=0.213, 95% CI [0.034, 0.397]. There was also significant between-study variance (τ=0.155, 95% CI [0.065, 0.367]). Mixture modeling to identify distinct classes of studies based on effect size and direction resulted in a 2-class model: The first class included four studies with an overall negative and moderate effect size (d=−0.478, 95% CI [−0.639, −0.318]), and the second class included the remaining 24 studies with an overall positive and significant, albeit small, effect size (d=0.141, 95% CI [0.084, 0.199]). Moderator analyses indicated that the strength and direction of the association between adversity and hair cortisol were moderated by features of the adversity exposure (e.g., type of adversity, timing of adversity), characteristics of the samples (e.g., clinical status, racial distribution), and features of the publication (e.g., publication type, geographic region of study). The findings refine our understanding of the long-term impact of adversity on dysregulation of the HPA axis, particularly as reflected in hair cortisol measures.

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Research on the hypothalamic pituitary adrenal (HPA) axis has involved a proliferation of cortisol indices. We surveyed recently published HPA-related articles and identified 15 such indices. We sought to clarify their biometric properties, specifically, how they interrelate and what they mean, because such information is rarely offered in the articles themselves. In the present article, the primary samples consist of community mothers and their infants (N = 297), who participated in two challenges, the Toy Frustration Paradigm and the Strange Situation Procedure. We sought to cross-validate findings from each of these samples against the other, and also against a clinically depressed sample (N = 48) and a sample of healthy older adults (N = 51) who participated in the Trier Social Stress Test. Cortisol was collected from all participants once before and twice after the challenges. These heterogenous samples were chosen to obtain the greatest possible range in cortisol levels and stress response regulation. Using these data, we computed the 15 summary cortisol indices identified in our literature survey. We assessed inter-relations amongst indices and determined their underlying dimensions via principal component analysis (PCA). The PCAs consistently extracted two components, accounting for 79%–93% of the variance. These components represent “total cortisol production” and “change in cortisol levels.” The components were highly congruent across challenge, time, and sample. High variable loadings and explained factor variance suggest that all indices represent their underlying dimensions very well. Thus the abundance of summary cortisol indices currently represented in the literature appears superfluous.

Cumulative risk (CR) models provide some of the most robust findings in the developmental literature, predicting numerous and varied outcomes. Typically, however, these outcomes are predicted one at a time, across different samples, using concurrent designs, longitudinal designs of short duration, or retrospective designs. We predicted that a single CR index, applied within a single sample, would prospectively predict diverse outcomes, i.e., depression, intelligence, school dropout, arrest, smoking, and physical disease from childhood to adulthood. Further, we predicted that number of risk factors would predict number of adverse outcomes (cumulative outcome; CO). We also predicted that early CR (assessed at age 5/6) explains variance in CO above and beyond that explained by subsequent risk (assessed at ages 12/13 and 19/20). The sample consisted of 284 individuals, 48% of whom were diagnosed with a speech/language disorder. Cumulative risk, assessed at 5/6-, 12/13-, and 19/20-years-old, predicted aforementioned outcomes at age 25/26 in every instance. Furthermore, number of risk factors was positively associated with number of negative outcomes. Finally, early risk accounted for variance beyond that explained by later risk in the prediction of CO. We discuss these findings in terms of five criteria posed by these data, positing a “mediated net of adversity” model, suggesting that CR may increase some central integrative factor, simultaneously augmenting risk across cognitive, quality of life, psychiatric and physical health outcomes.

Prenatal alcohol exposure is associated with a constellation of adverse physical, neurocognitive and behavior outcomes, which comprise a continuum of disorders labeled Fetal Alcohol Spectrum Disorders (FASD). Extant research has consistently identified executive functions (EF) as a central impairment associated with FASD. Despite this, heterogeneity exists regarding the strength of the association between FASD and different EF, and this association has not yet been quantitatively synthesized. The current meta-analysis reviews 46 studies that compare children and adolescents with FASD to participants without FASD, on a variety of EF measures. In accordance with Miyake et al. Cognitive Psychology, 41, 49-100 (2000) three-factor model of EF, findings for the primary EF domains of working memory, inhibition, and set shifting are reviewed. Results indicate that children and adolescents with FASD demonstrate significant deficits across these EF, although the magnitude of effects diverged between EF, with working memory and inhibition yielding medium effects and set shifting yielding large effects. These results were moderated by sample characteristics, type of FASD diagnosis, and EF methodology. This quantitative synthesis offers novel future research directions.

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