Recruiting participants for studies of early-life longitudinal development is challenging, often resulting in practical upper bounds in sample size and missing data due to attrition. These factors pose risks for the statistical power of such studies depending on the intended analytic model. One mitigation strategy is to increase measurement…

Research has shown that intrapersonal, interpersonal, and stress factors are associated with development in marital satisfaction. However, the unique contributions of early predictors and changes in these factors to the development of marital satisfaction have been overlooked. Based on data from 268 Chinese newlywed couples (M[subscript age] =…

Previous research is inconsistent as to whether a more labile (faster-changing) autonomic system confers performance advantages, or disadvantages, in infants and children. To examine this, we presented a stimulus battery consisting of mixed static and dynamic viewing materials to a cohort of 63 typical 12-month-old infants. While viewing the…

Research on age differences in the experience of negative emotional states have produced inconsistent results, particularly when emotion is examined in the context of daily stress. Strength and vulnerability integration (SAVI; Charles, 2010) theory postulates that age differences in emotional states are contingent upon whether a stressor occurred,…

While much research has focused on understanding the process by which young children learn to count, little work has explored the effects of direct instruction on this process. In the current study, we explored the impacts of training children in an explicit counting procedure on two distinct cardinality tasks. Two- to 5-year-old children first…

Across three studies, we examined 4- to 7-year-olds' predictions of goal-directed behaviors when goals conflict with preferences. In Study 1, when presented with stories in which a character had to act against basic preferences to achieve an interpersonal goal (e.g., playing with a partner), 6- and 7-year-olds were more likely than 4- and…

The capacity to plan ahead and provide the means for future ends is an important part of human practical reasoning. When this capacity develops in ontogeny is the matter of an ongoing debate. In this study, 4- and 5-year-olds performed a future planning task in which they had to create the means (a picture of a particular object, e.g., a banana)…

Although looking-time methods have long been used to measure infant attention and investigate aspects of cognitive development, steady-state visually evoked potential (SSVEP) measures may be more sensitive or practical in some contexts. Here, we demonstrate habituation of infants' SSVEP amplitudes to a flickering checkerboard stimulus, and…

Our social world is rich with information about other people's choices, which subsequently inform our inferences about their future behavior. For individuals socialized within the American cultural context, which places a high value on autonomy and independence, outcomes that are the result of an agent's own choices may hold more predictive value…

The early years of marriage are a time of significant personal and relational changes as partners adjust to their new roles, but the specific ways that spouses' personalities may change in early marriage and how these changes are associated with spouses' marital satisfaction trajectories have been overlooked. Using 3 waves of data collected over…

Much is known about young children's helping behavior, but little is known about the underlying motivations and emotions involved. In 2 studies we found that 2-year-old children showed positive emotions of similar magnitude--as measured by changes in their postural elevation using depth sensor imaging technology--after they achieved a goal for…

The article examines the role of infant-directed vocabulary (IDV) in infants language acquisition, specifically addressing the question of whether IDV forms that are not prominent in adult language may nonetheless be useful to the process of acquisition. Japanese IDV offers a good test case, as IDV characteristically takes a bisyllabic…

Constructivist views of cognitive development often converge on 2 key points: (1) the child's goal is to build large conceptual structures for understanding the world, and (2) the child plays an active role in developing these structures. While previous research has demonstrated that young children show a precocious capacity for concept and theory…

Childhood gender nonconformity (femininity in males, masculinity in females) predicts a nonstraight (gay, lesbian, or bisexual) sexual orientation in adulthood. In previous work, nonstraight twins reported more childhood gender nonconformity than their genetically identical, but straight, cotwins. However, self-reports could be biased. We…

Prior evidence has suggested that preschoolers and elementary schoolers search information largely with no systematic plan when making decisions in probabilistic environments. However, this finding might be due to the insensitivity of standard classification methods that assume a lack of variance in decision strategies for tasks of the same kind.…