The present study examines variation in the effect of birth weight on children's early cognitive and socioemotional outcomes by family socioeconomic status (SES). It is hypothesized that not only will lower birth weight children display worse cognitive and socioemotional outcomes prior to school entry, as prior research has found, but that effects…

This study provides empirical benchmarks that quantify typical changes in students' reports of social and emotional skills in a large, diverse sample. Data come from six cohorts of students (N = 361,815; 6% Asian, 8% Black, 68% White, 75% Latinx, 50% Female) who responded to the CORE survey from 2015 to 2018 and help quantify typical…

This study evaluated the impact of a parenting intervention on children's cognitive and socioemotional development in a group of caregivers and their 21-to-28-month-old children in a low-income South African township. A randomized controlled trial compared an experimental group (n = 70) receiving training in dialogic book-sharing (8 weekly group…

The Wechsler Preschool and Primary Scale of Intelligence, 4th ed. includes two measures of working memory normed on children 2;6-7;7. The present analyses of the typically developing children (N = 1,591, 812 female, 779 male, with an ethnic distribution approximating the United States) provide new, theoretically important information about these…

In this study, infant vocabulary development was tracked in a multilingual society (Singapore) within a socioeconomically diverse sample. The sample comprised 1316 infants from 17.4 to 27.7 months (669 females, 647 males; 88% Chinese race, 4% Malay, 4% Indian, and 0.004% mixed-race [4% declined to provide race information]). Children varied in…

Two preregistered experiments (N = 218) investigated children's developing ability to respond reasonably to disagreement. U.S. children aged 4-9, and adults (50% female, mostly white) formed an initial belief, and were confronted with the belief of a disagreeing other, whose evidence was weaker, stronger than, or equal to participants' evidence.…

How does one assess developmental change when the measures themselves change with development? Most developmental studies of word learning use either looking (infants) or pointing (preschoolers and older). With little empirical evidence of the relationship between the two measures, developmental change is difficult to assess. This paper analyzes…

This study investigates the influence of semantic maturation on early lexical development by examining the impact of contextual diversity--known to influence semantic development--on word promotion from receptive to productive vocabularies (i.e., comprehension-expression gap). Study 1 compares the vocabularies of 3685 American-English-speaking…

While social difficulties in autism are well-established, questions remain regarding whether these represent challenges in "acquiring" or "performing" such skills, reduced social strengths, or a unique distribution across these domains (i.e., social profile). This study empirically derived social profiles of 211 autistic and…

According to the failure model (Patterson & Capaldi, 1990), peer rejection is the intermediary link between problem behaviors and internalizing symptoms. The present study tested the model with 464 monozygotic and same-sex dizygotic twin pairs (234 female, 230 male dyads). Teacher-reported reactive aggression and internalizing symptoms, and…

This study investigated whether infants encode better the features of a briefly occluded object if its movements are specified simultaneously by vision and audition than if they are not (data collected: 2017-2019). Experiment 1 showed that 10-month-old infants (N = 39, 22 females, White-English) notice changes in the visual pattern on the object…

A double-blind randomized controlled trial of n-3 long-chain polyunsaturated fatty acid (n-3 LCPUFA) supplementation or matching placebo during third trimester of pregnancy was conducted within the COPSAC[subscript 2010] mother-child cohort consisting of 736 women and their children. The objective was to determine if maternal n-3 LCPUFA pregnancy…

Early social experiences, such as caregiver scaffolding, play a crucial but disputed role in the emergence of prosociality. A longitudinal experiment examined how explicit scaffolding--such as encouragement or praise--influences helping late in the first year, when helping emerges. Eighty-three infants (40 female, 6-9 months, 54% White, 17%…

Several studies have previously investigated the effects of sticky mittens training on reaching and grasping development. However, recent critique casted doubts on the robustness of the motor effect of this training. The current study presents a pre-registered report that aimed to generalize these effects to Swedish infants. Three-month-old…

Previous research shows that the development of response inhibition and drawing skill are linked. The current research investigated whether this association reflects a more fundamental link between response inhibition and motor control. In Experiment 1, 3- and 4-year-olds (n = 100) were tested on measures of inhibition, fine motor control, and…