Meta-Analysis of Meta-Analyses in Communication: Comparing Fixed Effects and Random Effects Analysis Models

Thirty-nine meta-analyses obtained from the past 10 years of communication research (1997–2007) were reanalyzed using fixed effects (FE), random effects (RE), and Hunter and Schmidt (HS) meta-analytic methods. The majority of studies (62%) reported use of the HS model in the original analysis. Differences identified between models include (a) greater propensity for Type 1 error under the FE approach, (b) episodes of inflated effect size (ES) under the RE approach, and (c) high levels of heterogeneity in population ESs across studies. Recommendations are made for scholars to appropriately choose and implement meta-analytic models in future research.     

Developmental Trajectories in Children With and Without Autism Spectrum Disorders: The First 3 Years

Retrospective studies indicate 2 major classes of autism spectrum disorder (ASD) onset: early and later, after a period of relatively healthy development. This prospective, longitudinal study examined social, language, and motor trajectories in 235 children with and without a sibling with autism, ages 6–36 months. Children were grouped as: ASD identified by 14 months, ASD identified after 14 months, and no ASD. Despite groups' initial similar developmental level at 6 months, ASD groups exhibited atypical trajectories thereafter. Impairment from 14 to 24 months was greater in the Early‐ASD than the Later‐ASD group, but comparable at 36 months. Developmental plateau and regression occurred in some children with ASD, regardless of timing of ASD diagnosis. Findings indicate a preclinical phase of varying duration for ASD.     

Infant Attachment Insecurity and Baseline Physiological Activity and Physiological Reactivity to Interpersonal Stress: A Meta-Analytic Review

This meta-analytic review (k = 5–10; N = 258–895) examined links between attachment insecurity and physiological activity at baseline and in response to interpersonal stress elicited by separation–reunion procedures in the early life course (1–5 years). Insecurity was trivially, nonsignificantly associated with baseline physiological activity (heart rate [HR]: g = −.06; respiratory sinus arrhythmia [RSA]: g = −.06; cortisol: g = .01) and nonsignificantly associated with physiological reactivity to separation from parents (HR: g = −.001; RSA: g = .24). However, insecurity was moderately associated with heightened RSA (g = .26) and cortisol (g = .27) reactivity upon reunion with parents. Findings provide insight into the biobehavioral organization of attachment, suggesting that early insecurity is associated with heightened physiological reactivity to interpersonal stress.     

Mothers' Physiological and Affective Responding to Infant Distress: Unique Antecedents of Avoidant and Resistant Attachments

In a sample of 127 mother–infant dyads, this study examined the predictive significance of mothers' physiological and observed emotional responding within distressing and nondistressing caregiving contexts at 6 months for infant attachment assessed with Fraley and Spieker's (2003) dimensional approach and the categorical approach at 12 months. Findings revealed that a lesser degree of maternal respiratory sinus arrhythmia withdrawal and higher levels of maternal neutral (vs. positive) affect within distressing (vs. nondistressing) caregiving contexts were distinctive antecedents of avoidance versus resistance assessed dimensionally (but not categorically), independent of maternal sensitivity. Discussion focuses on the usefulness of examining mothers' physiological and affective responding, considering the caregiving context, and employing the dimensional approach to attachment in identifying unique antecedents of patterns of attachment insecurity.