Knowledge about the functional status of the frontal cortex in infancy is limited. This study investigated the effects of polymorphisms in four dopamine system genes on performance in a task developed to assess such functioning, the Freeze-Frame task, at 9 months of age. Polymorphisms in the catechol-O-methyltransferase ("COMT") and the dopamine…

Three- and 4-year-old children were asked to judge which of a set of 3 lines was the longest, both independently and in the face of an inaccurate consensus among adult informants. Children were invariably accurate when making independent judgments but sometimes deferred to the inaccurate consensus. Nevertheless, the deference displayed by both age…

A broad array of research findings suggest that older adults, as compared with younger adults, have a more positive sense of self and possibly a clearer and more consistent sense of self. Further, older adults report lower motivation to construct or maintain a sense of self. In the present study, we examined whether such differences in self-views…

Serial-order short-term memory (STM), as opposed to item STM, has been shown to be very consistently associated with lexical learning abilities in cross-sectional study designs. This study investigated longitudinal predictions between serial-order STM and vocabulary development. Tasks maximizing the temporary retention of either serial-order or…

In this study, the authors compared the behavioral development of 4- to 8-year-old South Korean children placed in institutional care (n = 230) or adopted internationally (n = 382), with age of entry, parental status, reason for institutionalization, and postinstitutionalization parental contact as risk factors for institutionalized children.…

Using a population-based sample of 263 individuals ranging from 6 to 89 years of age, we investigated the gains and losses in the abilities to (a) use exogenous cues to shift attention covertly and (b) ignore conflicting information across the life span. The participants' ability to shift visual attention was tested by a typical Posner-type…

Multiple levels of category inclusiveness in 4 object domains (animals, vehicles, fruit, and furniture) were examined using a sequential touching procedure and assessed in both individual and group analyses in eighty 12-, 18-, 24-, and 30-month-olds. The roles of stimulus discriminability and child motor development, fatigue, and actions were also…

This study examined the developing object knowledge of infants through their visual anticipation of action targets during action observation. Infants (6, 8, 12, 14, and 16 months) and adults watched short movies of a person using 3 different everyday objects. Participants were presented with objects being brought either to a correct or to an…

This research examined the effects of bimodal audiovisual and unimodal visual stimulation on infants' memory for the visual orientation of a moving toy hammer following a 5-min, 2-week, or 1-month retention interval. According to the intersensory redundancy hypothesis (L. E. Bahrick & R. Lickliter, 2000; L. E. Bahrick, R. Lickliter, & R. Flom,…

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…

Prior studies indicate that children vary widely in their mathematical knowledge by the time they enter preschool and that this variation predicts levels of achievement in elementary school. In a longitudinal study of a diverse sample of 44 preschool children, we examined the extent to which their understanding of the cardinal meanings of the…

Duncan et al. (2007) examined associations between early behavioral and cognitive skills with later achievement. These associations were examined in 6 different data sets and results converged to suggest that early behavioral competences or problems had little, if any, prediction to later achievement and that attentional competences had small…

Ten- and 14-month-old infants' gaze was recorded as the infants observed videos of different hand actions directed toward multiple goals. Infants observed an actor who (a) reached for objects and displaced them, (b) reached for objects and placed them inside containers, or (c) moved his fisted hand. Fourteen-month-olds, but not 10-month-olds,…

This study investigated the prospective links between sibling aggression and the development of externalizing problems using a multilevel modeling approach with a genetically sensitive design. The sample consisted of 780 adolescents (390 sibling pairs) who participated in 2 waves of the Nonshared Environment in Adolescent Development project.…

Research has supported the existence of distinct behavioral patterns, demographic correlates, and etiologic mechanisms for aggressive (AGG) versus nonaggressive but delinquent (DEL) antisocial behavior. Though behavioral genetic studies have the potential to further crystallize these dimensions, inconsistent results have limited their…