The genetic effects on individual differences in reading development were examined using genome-wide complex trait analysis (GCTA) in a twin sample. In unrelated individuals (one twin per pair, n = 2,942), the GCTA-based heritability of reading fluency was ~20%-29% at ages 7 and 12. GCTA bivariate results showed that the phenotypic stability of…

Two experiments investigated response tendencies of preschoolers toward yes-no questions about actions. Two hundred 2- to 5-year-old children were asked questions concerning actions commonly associated with particular objects (e.g., drinking from a cup) and actions not commonly associated with particular objects (e.g., kicking a toothbrush). The…

This study investigated the spatial analysis of tactile hierarchical patterns in 110 early-blind children aged 6-8 to 16-18 years, as compared to 90 blindfolded sighted children, in a naming and haptic drawing task. The results revealed that regardless of visual status, young children predominantly produced local responses in both tasks, whereas…

This research traces the development of symbol-infused joint engagement during mother-child interactions into the preschool years. Forty-nine children, who had been previously observed as toddlers (L. B. Adamson, R. Bakeman, & D. F. Deckner), [Adamson, L. B., 2004], were systematically observed during interactions with their mothers at ages…

To examine early developments in other-oriented resource sharing, fifty-one 18- and 24-month-old children were administered 6 tasks with toys or food that could be shared with an adult playmate who had none. On each task the playmate communicated her desire for the items in a series of progressively more explicit cues. Twenty-four-month-olds…

This study examined the contribution of nonparental child-care services received during the preschool years to the development of social behavior between kindergarten and the end of elementary school with a birth cohort from Québec, Canada (N = 1,544). Mothers reported on the use of child-care services, while elementary school teachers rated…

This study investigated the changing relation between emotion and inhibitory control during adolescence. One hundred participants between 11 and 25 years of age performed a go-nogo task in which task-relevant stimuli (letters) were presented at the center of large task-irrelevant images depicting negative, positive, or neutral scenes selected from…

Four- to 10-year-olds' and adults' (N = 263) ability to inhibit privileged knowledge and simulate a naïve perspective were examined. Participants viewed pictures that were then occluded aside from a small ambiguous part. They offered suggestions for how a naïve person might interpret the hidden pictures, as well as rated the probability…

Children rely on both evidence and prior knowledge to make physical causal inferences; this study explores whether they make attributions about others' behavior in the same manner. A total of one hundred and fifty-nine 4- and 6-year-olds saw 2 dolls interacting with 2 activities, and explained the dolls' actions. In the person condition, each doll…

Infants require locomotor experience to behave adaptively at a drop-off. However, different experimental paradigms (visual cliff and actual gaps and slopes) have generated conflicting findings regarding what infants learn and the specificity of their learning. An actual, adjustable drop-off apparatus was used to investigate whether learning to…

Three experiments examine 18- to 24-month-old (N = 78) toddlers' ability to spatially orient objects by their major axes for insertion into a slot. This is a simplified version of the posting task that is commonly used to measure dorsal stream functioning. The experiments identify marked developmental changes in children's ability to preorient…

The neurocognitive development of moral and conventional judgments was examined. Event-related potentials were recorded while 24 adolescents (13 years) and 30 young adults (20 years) read scenarios with 1 of 3 endings: moral violations, conventional violations, or neutral acts. Participants judged whether the act was acceptable or unacceptable…

Actigraphs and parent and observer ratings were used to explore genetic influences on continuity and change in activity level (AL) in early childhood. Over 300 pairs of twins wore actigraphs for a 48-hr period in the home and laboratory at ages 2 and 3. AL was genetically influenced at both ages with little evidence of differential heritability…

The hypothesis that children develop an understanding of causal mechanisms was tested across 3 experiments. In Experiment 1 (N = 48), preschoolers had to choose as efficacious either a cause that had worked in the past, but was now disconnected from its effect, or a cause that had failed to work previously, but was now connected. Four-year-olds…

In human adults, visual dominance emerges in several multisensory tasks. In children, auditory dominance has been reported up to 4 years of age. To establish when sensory dominance changes during development, 41 children (6-7, 9-10, and 11-12 years) were tested on the Colavita task (Experiment 1) and 32 children (6-7, 9-10, and 11-12 years) were…