Children show less positivity toward gender-nonconforming (GN) than gender-conforming (GC) peers. Yet, little is known about children's reasoning about peers of varying gender expressions, including age-, gender-, and culture-related influences. We investigated how children aged 4- to 5- and 8- to 9-years-old in Hong Kong and Canada (N = 678)…

Third-party punishment has been regarded as an important mechanism to promote fairness. Although previous research has shown that children aged 6 and older punish unfair behaviors at a personal cost, it is unknown whether they actually intend to establish equality or whether equality is a mere byproduct of punishment. In this preregistered study,…

Little is known about the development of procrastination, the tendency to postpone undesirable but necessary tasks, during early childhood. Only one study has measured procrastination behavior in preschool children using a single behavioral task (Sutter et al., 2018). Thus, the present study investigated the emergence and development of everyday…

Brain age, a measure of biological aging in the brain, has been linked to psychiatric illness, principally in adult populations. Components of socioeconomic status (SES) associate with differences in brain structure and psychiatric risk across the lifespan. This study aimed to investigate the influence of SES on brain aging in childhood and…

Given the value placed on honesty and the negative consequences of lying, encouraging children's truth-telling is important. The present investigation assessed honesty promotion techniques for encouraging 3-8-year-old Canadian children's (Study 1: n = 301, 54% female; Study 2: n = 229, 50% female from predominantly White middle-class samples)…

The development of strategies that support autonomous self-regulation of emotion is key for early childhood emotion regulation. Children are thought to transition from predominant reliance on more automatic or interpersonal strategies to reliance on more effortful, autonomous strategies as they develop cognitive skills that can be recruited for…

To successfully navigate an uncertain world, one has to learn the relationship between cues (e.g., wind speed, atmospheric pressure) and outcomes (e.g., rain). When learning, it is possible to actively manipulate the cue values to test hypotheses about this relationship directly. Across two studies, we investigated how 5- to 7-year-olds actively…

Infants can help and share in the second year of life. However, there is limited knowledge as to variability in these behaviors as a function of target (e.g., caregiver vs. unfamiliar adult) and the influence of caregiver support on infant prosocial behavior. Infants (N = 268, 124 female) at 1-2 years of age (M = 1.47, SD = 0.27) and again at 2-3…

Social cognition is a set of complex processes that mediate much of human behavior. The development of these skills is related to and interdependent on other cognitive processes, particularly inhibitory control. Brain regions associated with inhibitory control and social cognition overlap functionally and structurally, especially with respect to…

The interrelationships between math and behavioral skill development prior to school entry are not well understood, yet have important implications for understanding how to best prepare young children for kindergarten. This study addresses this gap by utilizing a sample of 1,750 children (53% male; 47% White, 16% Black, 16% Hispanic, 8% Asian, and…

Parasympathetic nervous system functioning as indexed by respiratory sinus arrhythmia (RSA) is widely used as a measure of physiological regulation. We examined developmental patterns of children's resting RSA and RSA reactivity from 2 to 15 years of age, a period of time that is marked by considerable advances in children's regulatory abilities.…

Anger is a central characteristic of negative affect and is relatively stable from infancy onward. Absolute levels of anger typically peak in early childhood and diminish as children become socialized and better able to regulate emotions. From infancy to school age, however, there are also individual differences in rank-order levels of anger. For…

The current study examines the extent to which associations between internalizing problems, body mass index (BMI), and language skills from early (36 months) to late childhood (fifth grade) are due to relatively stable between-child differences, time-specific correlations, or cross-lagged paths. Data from the NICHD study, Early Child Care and…

Inhibitory control has been widely studied in association with social and academic adjustment. However, prior studies have generally overlooked the potential heterotypic continuity of inhibitory control and how this could affect assessment and understanding of its development. In the present study, we systematically considered heterotypic…

Around their first birthdays, infants begin to point, walk, and talk. These abilities are appreciable both by researchers with strictly standardized criteria and caregivers with more relaxed notions of what each of these skills entails. Here, we compare the onsets of these skills and links among them across two data collection methods: observation…