The aim of this longitudinal study is to evaluate 3 views on the relationship between nonword repetition and vocabulary: (i) the storage-based view that considers nonword repetition, a measure of phonological storage, as the driving force behind vocabulary development, (ii) the lexical restructuring view that considers improvements in nonword…

Our newly proposed integrated academic self-concept model integrates 3 major theories of academic self-concept formation and developmental perspectives into a unified conceptual and methodological framework. Relations among math self-concept (MSC), school grades, test scores, and school-level contextual effects over 6 years, from the end of…

Both genetic and environmental factors contribute to individual differences in aggression. Catechol-O-methyltransferase Val158Met (COMT), a common, functional polymorphism, has been implicated in aggression and aggression traits, as have childhood experiences of adversity. It is unknown whether these effects are additive or interactional and, in…

Although social difficulties have been identified as sequelae of children's experiences with interparental conflict and insecurity, little is known about the specific mechanisms underlying their vulnerability to social problems. Guided by emotional security theory, this study tested the hypothesis that children's emotional insecurity mediates…

In this longitudinal study, we tested whether the association between oppositional defiance to parental authority (i.e., adolescents' tendency to bluntly reject parental rules) and autonomy would depend upon the specific conceptualization of autonomy. Whereas oppositional defiance would yield more interpersonal distance from parents, because…

The link between behavior problems and low academic achievement is well established, but few studies have examined longitudinal relations between early externalizing behaviors before school entry and low academic achievement following transition to formal schooling. Early inattention has been particularly overlooked, despite strong associations…

Conceptual change requires learners to restructure parts of their conceptual knowledge base. Prior research has identified the fragmentation and the integration of knowledge as 2 important component processes of knowledge restructuring but remains unclear as to their relative importance and the time of their occurrence during development. Previous…

Building on empirical documentation of children's involvement in interparental conflicts as a weak predictor of psychopathology, we tested the hypothesis that involvement in conflict more consistently serves as a moderator of associations between children's emotional reactivity to interparental conflict and their psychological problems. In Study…

Drawing on the expectancy-value model, the present study explored individual and gender differences in university entry and selection of educational pathway (e.g., science, technology, engineering, and mathematics [STEM] course selection). In particular, we examined the multiplicative effects of expectancy and task values on educational outcomes…

Zimmerman, Christakis, and Meltzoff (2007) reported that exposure to Baby Einstein videos was negatively associated with language development. The current study uses the Zimmerman et al. (2007) data set to replicate and extend the original analyses. Caregivers of 392 children aged 6 to 16 months and 358 children aged 17 to 27 months reported on…

Steinberg and Monahan's (2011) reanalysis of the Teen Media longitudinal survey of adolescents does not meet prevailing standards for propensity score analysis and therefore does not undermine the original conclusions of the Brown, L'Engle, Pardun, Guo, Kenneavy, and Jackson (2006) analysis. The media do matter in the sexual socialization of…

We examined developmental and individual differences in 6th and 8th graders' fraction arithmetic and overall mathematics achievement and related them to differences in understanding of fraction magnitudes, whole number division, executive functioning, and metacognitive judgments within a cross-sectional design. Results indicated that the…

Duncan et al. (2007) presented a new methodology for identifying kindergarten readiness factors and quantifying their importance by determining which of children's developing skills measured around kindergarten entrance would predict later reading and math achievement. This article extends Duncan et al.'s work to identify kindergarten readiness…

In this article we replicate and extend findings from Duncan et al. (2007). The 1st study used Canada-wide data on 1,521 children from the National Longitudinal Survey of Children and Youth (NLSCY) to examine the influence of kindergarten literacy and math skills, mother-reported attention, and mother-reported socioemotional behaviors on 3rd-grade…