This is a longitudinal study of development in coordinated mother-infant vocal interaction from 4 to 10 months (N = 41) focusing on the development of turn-taking patterns and time spent in coordinated vocal interaction. Data analyses were carried out using multistate analysis. Both mothers and infants were found to coordinate their own…

This study tested 2 related hypotheses. The first holds that high co-rumination anticipates heightened internalizing problems. The second holds that positive relationships with friends exacerbate the risk for internalizing problems arising from co-rumination. A sample of MZ twins followed from birth (194 girls and 170 boys) completed (a)…

Recent studies demonstrate that emerging literacy depends on earlier language achievement. Importantly, most extant work focuses on "parent-reported production" prior to 30 months of age. Of interest is whether and how "directly assessed vocabulary comprehension" in the 2nd year of life supports vocabulary and kindergarten…

This study examined relations of social sensitivity to social, school, and psychological adjustment in rural Chinese, urban Chinese, and Canadian children. Participants were 4th to 6th grade students (M[subscript age] = 11 years) in China (n = 593 and 443 for the rural and urban samples) and Canada (n = 325). A self-report measure of social…

We investigated the role of sociocultural (between-groups) and individual (within-group) factors on the development of preschoolers' resource-allocation preferences. We tested claims of the "joint impact hypothesis" of social values development that social-emotional understanding skills would predict the transition from simpler…

Children's eating behavior influences energy intake and thus weight through choices of type and amount of food. One type of eating behavior, food responsiveness, defined as eating in response to external cues such as the sight and smell of food, is particularly related to increased caloric intake and weight. Because little is known about the…

Youth who exhibit externalizing problems during childhood and adolescence are at an increased risk for a wide range of detrimental life outcomes. Despite the profound consequences of externalizing problems for children, their families, and their communities, we know less about the precise trajectory of externalizing symptoms across late childhood…

Late-life well-being often shows steep deteriorations, but the contributing factors are not well understood, in part because data about people's final year of life are scarce. Here, we draw from and test theoretical perspectives that health-related vulnerabilities undermine the experience and skills older adults typically use to maintain…

Is compulsive Internet use (CIU) an antecedent to poor mental health, a consequence, or both? Study 1 used a longitudinal design to track the development of CIU and mental health in Grade 8 (N = 1,030 males, 1,038 females, M[subscript age] = 13.7), 9, 10, and 11. Study 2 extended Study 1 by examining the kinds of Internet behaviors most strongly…

During adolescence, gender identity (GI) develops through a dialectic process of personal reflection and with input from the social environment. Peers play an important role in the socialization of gendered behavior, but no studies to-date have assessed peer influences on GI. Thus, the goal of the present study was to examine peer influences on…

We assessed 5-to 11-year-olds' (N = 76) judgments of straightforward moral transgressions (prototypical harm) as well as their evaluations of complex, hypothetical scenarios in which an actor transgresses in order to prevent injury (necessary harm). The nature of the actor's transgression (psychological or physical harm) varied across…

Despite the large body of knowledge on adults suggesting that 2 basic types of mental spatial transformation--namely, object-based and egocentric perspective transformations--are dissociable and specialized for different situations, there is much less research investigating the developmental aspects of such spatial transformation systems. Here, an…

Girls who experience earlier pubertal timing relative to peers also exhibit earlier timing of sexual intercourse and more unstable sexual relationships. Although pubertal development initiates feelings of physical desire, the transition into romantic and sexual relationships involves complex biological and social processes contributing both to…

Visual appearance is one of the main cues children rely on when categorizing novel objects. In 3 studies, testing 128 3-year-olds and 192 5-year-olds, we investigated how various kinds of information may differentially lead children to overlook visual appearance in their categorization decisions across domains. Participants saw novel animals or…

Positive emotional engagement develops in the context of face-to-face interactions during the first 6 months of life. Deficits in emotional engagement are characteristic of autism spectrum disorder (ASD) and may characterize the younger siblings of children with ASD (high-risk siblings). High-risk siblings are likely to exhibit a broad range of…