Moral justifications work, when they do, by invoking values that are shared in the common ground of the interlocutors. We asked 3- and 5-year-old peer dyads (N = 144) to identify and punish norm transgressors. In the moral condition, the transgressor violated a moral norm (e.g., by stealing); in the social rules condition, she/he violated a…

Given the centrality of prosociality in everyday social functioning, understanding the factors and mechanisms underlying the origins of prosocial development is of critical importance. This experiment investigated whether experience with reciprocal object exchanges can drive the developmental onset of sharing behavior. Seven-month-old infants took…

Over the past few decades, there has been extensive debate as to whether humans represent number abstractly and, if so, whether perceptual features of a set such as cumulative surface area or contour length are extracted more readily than number from the external world. Here we show that 7-month-old infants are sensitive to smaller ratio changes…

Infants' motor skill development triggers changes in parent-infant interactions, exploration, and play behaviors, particularly during periods of locomotor transitions. We investigated how these transitions reorganized infants' and mothers' explorations of spatial layouts. Thirteen infants and their mothers were followed biweekly from the age of 6…

Given that maternal support promotes healthy social and emotional development in early childhood, it is important to understand the predictors of such support, especially during emotional challenges. In this study, mothers' dispositional distress reactivity (i.e., the tendency toward experiencing distress in response to children's negative…

Inconsistent parental discipline is a robust correlate of child attention-deficit/hyperactivity disorder (ADHD) symptoms, but few studies have considered the role of inconsistent "positive" parenting on ADHD, as well as the effects of stress on negative and positive parental consistency. This study advanced a novel ecological momentary…

Parent behaviors moderate the adverse consequences of pediatric traumatic brain injury (TBI); however, it is unknown how these moderating effects change over time. This study examined the moderating effect of observed parent behaviors over time since injury on the relation between TBI and behavioral outcomes. Participants included children, ages…

The goals of this study were to investigate whether young children attending Head Start (N = 292; M[subscript age] = 4.3 years) selected peers based on their preschool competency and whether children's levels of preschool competency were influenced by their peers' levels of preschool competency. Children's peer interaction partners were…

Research on family socialization of positive emotion has primarily focused on the infant and toddler stages of development, and relied on observations of parent-child interactions in highly structured laboratory environments. Little is known about how children's spontaneous expressions of positive emotion are maintained in the uncontrolled…

The goal of this study was to determine whether peer social competence (SC), defined as the capacity to use behavioral, cognitive, and emotional resources in the service of achieving personal goals within preschool peer groups, was related to the type of affiliative subgroups to which children belonged. Two hundred forty Portuguese preschool…

The development of prosocial behaviors during the preschool years is essential for children's positive interactions with peers in school and other social situations. Although there is some evidence of genetic influences on prosocial behaviors, very little is known about how genes and environment, independently and in concert, affect prosocial…

We propose a model linking the early parent-child mutually responsive orientation (MRO), children's temperament trait of effortful control, and their internalization of conduct rules. In a developmental chain, effortful control was posited as a mediator of the links between MRO and children's internalization. MRO was further posited as a moderator…

A transactional model examining the longitudinal association between vagal regulation (as indexed by vagal withdrawal) and maternal sensitivity from age 2.5 to age 5.5 was assessed. The sample included 356 children (171 male, 185 female) and their mothers who participated in a laboratory visit at age 2.5, 4.5, and 5.5. Cardiac vagal tone was…

Guided by a dyadic view of children's peer behavior, this study assessed actor and partner effects of attachment security and temperament on young children's behavior with an unfamiliar peer. At 33 months of age, child-mother attachment security was assessed via a modified Strange Situation procedure, and parents reported on child temperament…

Previous studies have demonstrated that various psychosocial risks are associated with poor cognitive functioning in children, and these risks frequently cluster together. In the current longitudinal study, we tested a model in which it was hypothesized that cumulative psychosocial adversity of mothers would have deleterious effects on children's…