Infants must develop both flexibility and constraint in their interpretation of acceptable word forms. The current experiments examined the development of infants' lexical interpretation of non-native variations in pitch contour. Fourteen-, 17-, and 19-month-olds (Experiments 1 and 2, N = 72) heard labels for two novel objects; labels…

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…

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…

Stress responses to social evaluation are thought to increase during adolescence, which may be due to pubertal maturation. However, empirical evidence is scarce. This study is the first to investigate the relation between pubertal development and biological responses to a social-evaluative stressor longitudinally. Participants performed the Leiden…

Place value notation is essential to mathematics learning. This study examined young children's (4-to 6-year-olds, N = 172) understanding of place value prior to explicit schooling by asking them write spoken numbers (e.g., "six hundred and forty-two"). Children's attempts often consisted of "expansions" in which the…

The concept of spreading activation describes how retrieval of one memory cues retrieval of other memories that are associated with it. This study explored spreading activation in 6-, 12-, and 18-month-old infants. Infants (n = 144) learned two tasks within the same experimental session; one task, deferred imitation (DI), is typically remembered…

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…

This study investigates how children negotiate social norms with peers. In Study 1, 48 pairs of 3- and 5-year-olds (N = 96) and in Study 2, 48 pairs of 5- and 7-year-olds (N = 96) were presented with sorting tasks with conflicting instructions (one child by color, the other by shape) or identical instructions. Three-year-olds differed from older…

This study examined judgments and reasoning about four parental discipline practices (induction or reasoning and three practices involving "psychological control"; Barber, 1996; two forms of shaming and love withdrawal) among children (7-14 years of age) from urban and rural China and Canada (N = 288) in response to a moral…

Mothers' mental-state references predict individual differences in preschoolers' false-belief (FB) understanding; less is known about the origins of corresponding variation in school-age children. To address this gap, 105 children completed observations with their mothers at child ages 2 and 6, three FB tasks and a verbal comprehension…

Panel mediation models and fixed-effects models were used to explore longitudinal relations among parents' reactions to children's displays of negative emotions, children's effortful control (EC), and children's math achievement (N = 291; M age in fall of kindergarten = 5.66 years, SD = 0.39 year) across kindergarten through…

Using an epidemiological sample (N = 1,117) and a prospective longitudinal design, this study tested the direct and indirect effects of preverbal and verbal communication (15 months to 3 years) on executive function (EF) at age 4 years. Results indicated that whereas gestures (15 months), as well as language (2 and 3 years), were correlated with…

With many features competing for attention in their visual environment, infants must learn to deploy attention toward informative cues while ignoring distractions. Three eye tracking experiments were conducted to investigate whether 6- and 8-month-olds (total N = 102) would shift attention away from a distractor stimulus to learn a cue-reward…

This study examined bidirectional associations between mothers' depressive symptoms and children's externalizing behavior and whether they were moderated by preschool-age effortful control and gender. Mothers and teachers reported on 224 primarily White, middle-class children at ages 3, 5, and 10. Effortful control was assessed via…

The protective role of strength of group identity was examined for youth in a context of protracted political conflict. Participants included 814 adolescents (M[subscript age] = 13.61, SD = 1.99 at Time 1) participating in a longitudinal study in Belfast, Northern Ireland. Utilizing hierarchical linear modeling, the results show that the effect of…