Kim and Opfer (2017) found that number-line estimates increased approximately logarithmically with number when an upper bound (e.g., 100 or 1000) was explicitly marked (bounded condition) and when no upper bound was marked (unbounded condition). Using procedural suggestions from Cohen and Ray (2020), we examined whether this logarithmicity might…

Toddlers' understanding of object rotation was investigated using a multimethod approach. Participants were 44 toddlers between 22 and 38 months of age. In an eye-tracking task, they observed a shape that rotated and disappeared briefly behind an occluder. In an object-fitting task, they rotated wooden blocks and fit them through apertures.…

Executive functions (EF) are domain-general cognitive skills that predict foundational academic skills such as literacy and numeracy. However, less is known about the relation between EFs and science achievement. The nature of this relation might be explained by the theory of mutualism, which states that development is the result of complex and…

Empathy and executive functions (EFs) are multimodal constructs that enable individuals to cope with their environment. Both abilities develop throughout childhood and are known to contribute to social behavior and academic performance in young adolescents. Notably, mentalizing and EF activate shared frontotemporal brain areas, which in previous…

Guided by evolutionary-developmental models, this study tested the hypothesis that children's exposure to parental relationship instability, defined by initiation and dissolution of caregiver intimate relationships, has both costs in cognitive impairments and benefits in enhanced learning skills. Participants included 243 mothers and their…

Over the last 2 centuries there has been a rapid increase in the proportion of children who grow up in cities. However, relatively little work has explored in detail the physiological and cognitive pathways through which city life may affect early development. To assess this, we observed a cohort of infants growing up in diverse settings across…

The manner in which mothers engage in emotional discussion, or reminisce, with their young children about past emotional experiences poses important ramifications for child socioemotional and cognitive development. Maltreating mothers may have difficulty engaging in emotionally supportive reminiscing. The current study examined the role of…

Children start preschool with large individual differences in their early numerical abilities. Little is known about the importance of heterogeneous patterns that exist within these individual differences. A person-centered analytic approach might be helpful to unravel these patterns and the cognitive and environmental factors that are associated…

To explore the potential contribution of parents' causal talk to preschooler's emerging scientific literacy and related interests, we observed 153 parent-child dyads playing together in a museum and in the lab. As in previous work, the frequency with which parents referenced causal information in their speech predicted the strength of their…

Several theories of executive function (EF) propose that EF development corresponds to children's ability to form representations and reflect on represented stimuli in the environment. However, research on early EF is primarily conducted with preschoolers, despite the fact that important developments in representation (e.g., language, gesture,…

Conceptual notions and empirical evidence suggest that the intraindividual correlation (iCorr) of positive affect (PA) and negative affect (NA) is a meaningful characteristic of affective functioning. PA and NA are typically negatively correlated within-person. Previous research has found that the iCorr of PA and NA is relatively stable over time…

Both early childhood maternal language input and the quality of classroom instruction in elementary school have been shown to be important environmental supports in predicting children's literacy skill development. However, no studies have simultaneously examined these two environmental supports in relation to children's early language skills and…

A wealth of literature has examined the association between breastfeeding and the development of cognitive abilities in childhood. In particular, at least some evidence exists suggesting that breastfed children perform better on measures of intelligence later in life. Although a correlation appears to be present, fewer observational studies have…

Humans possess a tendency to rapidly and consistently make character evaluations from mere facial appearance. Recent work shows that this tendency emerges surprisingly early: children as young as 3-years-old provide adult-like assessments of others on character attributes such as "nice," "strong," and "smart" based…

Fragmented sleep is common in infancy. Although night awakening is known to decrease with age, in some infants night awakening is more persistent and continues into older ages. However, the influence of fragmented sleep on development is poorly known. In the present study, the longitudinal relationship between fragmented sleep and psychomotor…