From very early in life, humans can approximate the number and surface area of objects in a scene. The ability to discriminate between 2 approximate quantities, whether number or area, critically depends on the ratio between the quantities, with the most difficult ratio that a participant can reliably discriminate known as the Weber fraction.…

In a series of 4 experiments, we tested children's understanding that the causes of their actions must necessarily be attributed to information known prior to (i.e., "pre-action" information), rather than after (i.e., "post-action" information), the completion of their actions. For example, children were shown a dog, asked…

This longitudinal study investigated whether variation in the oxytocin receptor gene (OXTR) and early parent-child interactions predicted later empathic behavior in 84 toddlers at high or low familial risk for autism spectrum disorder. Two well-studied OXTR single-nucleotide polymorphisms, rs53576 and rs2254298, were examined. Parent-child…

Twenty-four 3.5-year-old children who initially showed poor performance on false-belief tasks participated in a training protocol designed to promote performance on these tasks. Our aim was to determine whether the extent to which children benefited from training was predicted by their performance on a battery of executive functioning tasks.…

Watch any crowded intersection, and you will see how adept people are at reading the subtle movements of one another. While adults can readily discriminate small differences in the direction of a moving person, it is unclear if this sensitivity is in place early in development. Here, we present evidence that 4-year-old children are sensitive to…

The relation of observed emotional reactivity and regulation in infancy to executive function in early childhood was examined in a prospective longitudinal sample of 1,292 children from predominantly low-income and rural communities. Children participated in a fear eliciting task at ages 7, 15, and 24 months and completed an executive function…

Gesture is an important precursor of children's early language development, for example, in the transition to multiword speech and as a predictor of later language abilities. However, it is unclear whether gestural input can influence children's comprehension of complex grammatical constructions. In Study 1, 3- (M = 3 years 5 months) and…

Consistent with models of environmental sensitivity (Pluess, 2015), research suggests that the effects of parents' behaviors on child adjustment are stronger among children who struggle to regulate their thoughts, feelings, and behaviors compared with children with better self-regulation. This study extended prior research by assessing maternal…

At the beginning of preschool (M = 46 months of age), 197 (94 boys) children were administered tasks that assessed a suite of nonsymbolic and symbolic quantitative competencies as well as their executive functions, verbal and nonverbal intelligence, preliteracy skills, and their parents' education level. The children's mathematics achievement was…

Manual dexterity is known to gradually progress with developmental age. In this study, we evaluate the performance of unimanual and bimanual actions under perturbed and unperturbed conditions in children between 4 and 10 years of age. Behavior was assessed by means of trajectory measurements and degree of bimanual coupling. The results showed that…

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…

Empirical research supporting the contention that insecure attachment is related to internalizing behaviors has been inconsistent. Across 60 studies including 5,236 families, we found a significant, small to medium effect size linking insecure attachment and internalizing behavior (observed d = 0.37, 95% CI [0.27, 0.46]; adjusted d = 0.19, 95% CI…

This study used a prospective adoption design to investigate effects of prenatal and postnatal parent depressive symptom exposure on child hypothalamic-pituitary-adrenal (HPA) activity and associated internalizing symptoms. Birth mother prenatal symptoms and adoptive mother/father postnatal (9-month, 27-month) symptoms were assessed with the Beck…

This study examined the origins of children's ability to make consciously false statements, a necessary component of lying. Children 2 to 5 years of age were rewarded for claiming that they saw a picture of a bird when viewing pictures of fish. They were asked outcome questions ("Do you win/lose?"), recognition questions ("Do you have a…

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…