A longitudinal study was conducted to identify unique sources of individual differences in later understanding of the equal sign as a relational symbol of equivalence (i.e., formal understanding of mathematical equivalence). The sample included 141 children from a mid-sized city in the Midwestern United States (M[subscript age] = 6 years, 2 months…

Research has shown that two different, though related, ways of representing magnitude play foundational roles in the development of numerical and mathematical skills: a nonverbal approximate number system and an exact symbolic number system. While there have been numerous studies suggesting that the two systems are important predictors of math…

Multiple studies have shown that children conform to majorities in perceptual judgment tasks against their better knowledge. However, these studies report contradictory results about how conformity develops over age. Here, we study variation in conformity over the course of middle childhood: we examined potential informational and normative…

Data from the Early Childhood Longitudinal Study (ECLS-K; N = 6,420; 67.9% White/non-Hispanic, 15% Hispanic, 13% Black/non-Hispanic, 2% Asian, 3% Native American/Alaska Native; 25% of parents' income <$25,000, 25% = $25,001 to $45,000, 29% = $45,001 to $75,000, 20% = $75,001 or greater) were used to test structural equation models in which…

There is currently considerable discussion about the relative influences of evolutionary and cultural factors in the development of early numerical skills. In particular, there has been substantial debate and study of the relationship between approximate, nonverbal (approximate magnitude system [AMS]) and exact, symbolic (symbolic number system…

Guided by models of family unpredictability, this study was designed to identify the distinctive sequelae of disorganized interparental conflict, a dimension of interparental conflict characterized by abrupt, inexplicable changes in parental emotional lability, conflict tactics, and verbalizations. Participants included 208 kindergarten children…

The present study examined, within a longitudinal family-informed design and across middle childhood, the predictive associations between preference for solitude and social wariness, two forms of social withdrawal, and peer difficulties. Specifically, preference for solitude, rather than social wariness, was expected to predict peer victimization…

This study examined developmental profiles of reading fluency and reading comprehension in Grades 1 to 9 (ages 7 to 15) in a large Finnish sample (N = 2,518). In addition, early predictors of the profiles were analyzed with respect to kindergarten cognitive skills (phonological awareness, letter knowledge, rapid automized naming [RAN], number…

In this study we evaluated whether the sophistication of children's invented spellings in kindergarten was predictive of subsequent reading and spelling in Grade 1, while also considering the influence of well-known precursors. Children in their first year of schooling (mean age = 66 months; N = 171) were assessed on measures of oral vocabulary,…

Guided primarily by life history theory, this study was designed to identify how and why early exposure to caregiver intimate relationship instability uniquely predicts children's externalizing symptoms in the context of other dimensions of unpredictability characterized by residential and parental job transitions. Participants included 243…

The current study aimed to substantiate and extend our understanding regarding the existence and developmental pathways of 3 distinct temperament profiles--exuberant, inhibited, and average approach--in a sample of 3.5-year-old children (n = 121). The interactions between temperamental styles and specific types of effortful control, inhibitory…

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…

This study examines the role of a particular kind of linguistic input--talk about the past and future, pretend, and explanations, that is, talk that is decontextualized--in the development of vocabulary, syntax, and narrative skill in typically developing (TD) children and children with pre- or perinatal brain injury (BI). Decontextualized talk…

Behavioral regulation is an important school readiness skill that has been linked to early executive function (EF) and later success in learning and school achievement. Although poverty and related risks, as well as negative parenting, have been associated with poorer EF and behavioral regulation, chaotic home environments may also play a role in…

This study assessed 562 four-year-old children at the beginning and end of their prekindergarten (pre-k) year and followed them to the end of kindergarten. At each time point children were assessed on 6 measures of executive function (EF) and 5 subtests of the Woodcock-Johnson III academic achievement battery. Exploratory factor analyses yielded…