Evidence from twin studies points to substantial environmental influences on intelligence, but the specifics of this influence are unclear. This study examined one developmental process that potentially causes intelligence differences: learning to read. In 1,890 twin pairs tested at 7, 9, 10, 12, and 16 years, a cross-lagged…

Category-based induction is a hallmark of mature cognition; however, little is known about its origins. This study evaluated the hypothesis that category-based induction is related to semantic development. Computational studies suggest that early on there is little differentiation among concepts, but learning and development lead to increased…

The present study followed a sample of first-grade (N = 316, M[subscript age] = 7.05 at first test) through fourth-grade students to evaluate dynamic developmental relations between vocabulary knowledge and reading comprehension. Using latent change score modeling, competing models were fit to the repeated measurements of vocabulary knowledge and…

Verbal memory is a fundamental prerequisite for language learning. This study investigated 7-month-olds' (N = 62) ability to remember the identity and order of elements in a multisyllabic word. The results indicate that infants detect changes in the order of edge syllables, or the identity of the middle syllables, but fail to encode the order…

Comparisons of cognitive processing in monolinguals and bilinguals have revealed a bilingual advantage in inhibitory control. Recent studies have demonstrated advantages associated with exposure to two languages in infancy. However, the domain specificity and scope of the infant bilingual advantage in infancy remains unclear. In the present study,…

Fiction presents a unique challenge to the developing child, in that children must learn when to generalize information from stories to the real world. This study examines how children acquire causal knowledge from storybooks, and whether children are sensitive to how closely the fictional world resembles reality. Preschoolers (N = 108) listened…

Despite evidence that young children are sensitive to differences in angle measure, older students frequently struggle to grasp this important mathematical concept. When making judgments about the size of angles, children often rely on erroneous dimensions such as the length of the angles' sides. The present study tested the possibility that…

Although ethnic and racial identity (ERI) are central to the normative development of youth of color, there have been few efforts to bring scholars together to discuss the theoretical complexities of these constructs and provide a synthesis of existing work. The Ethnic and Racial Identity in the 21st Century Study Group was assembled for this…

This study assesses the consequences of housing instability during the first 5 years of a child's life for a host of school readiness outcomes. Using data from the Fragile Families and Child Wellbeing Study (n = 2,810), this study examines the relation between multiple moves and children's language and literacy and behavior problems at…

Infants' ability to mentally track the orientation of an object during a hidden rotation was investigated (N = 28 in each experiment). A toy on a turntable was fully covered and then rotated 90°. When revealed, the toy had turned with the turntable (probable event), remained at its starting orientation (improbable event in Experiment 1), or…

Within-individual variability is such an apparent characteristic of infant handedness that handedness is believed to consolidate only in childhood. Research showed that manifest handedness is influenced by emerging postural skills (sitting, crawling, and walking). In this investigation, it was proposed that symmetric hand-use (tendency to acquire…

This study provides evidence that children give priority to ownership when judging who should use an object. Children (N = 269) and adults (N = 154) considered disputes over objects. In disputes between a character using an object and the owner of the object, children, as young as 3 years and as old as 7 years, sided with the owner, and did so…

This study tested whether the mediational pathway involving interparental conflict, adolescent emotional insecurity, and their psychological problems was altered by their earlier childhood histories of insecurity. Participants included 230 families, with the first of the five measurement occasions occurring when children were in first grade…

Infants' visual short-term memory (VSTM) for simple objects undergoes dramatic development: Six-month-old infants can store in VSTM information about only a simple object presented in isolation, whereas 8-month-old infants can store information about simple objects presented in multiple-item arrays. This study extended this work to examine…

Utilizing a longitudinal sample of Finnish children (ages 6-10), two studies examined how early linguistic (spoken vs. written) and spatial skills predict later development of arithmetic, and whether counting sequence knowledge mediates these associations. In Study 1 (N = 1,880), letter knowledge and spatial visualization, measured in…