Fractions are a challenging mathematics topic for many elementary and middle school students, and even for adults. However, a growing body of developmental research suggests that young children can reason about visually presented proportions, well before fraction instruction, providing insight into how fractions might be introduced to improve…

Understanding of the complement principle has been proposed as closely related to computational skills, but few studies have investigated their interrelations. The present longitudinal study attempted to clarify the picture by examining their potential cross-lagged relation. Fourth graders (n = 221) in Hong Kong received 3 cognitive assessments at…

Prospective memory (PM) involves remembering to carry out intended actions in the future (e.g., posting a letter on the way to school or passing on a message) and is important for children's independent functioning in daily life. This study examined, for the first time, the effects of incidental reminder cues on children's PM. Five- and 7-year-old…

Two experiments investigated perceived and physiological changes in anxiety in children (7-11 years; N = 222; 98 female) in a performance situation after they observed another child in a similar situation with a negative or neutral outcome. The sample's London, United Kingdom, school catchment areas ranged from low to high socioeconomic statuses…

The use of a verbal rehearsal strategy (repeating the items to be remembered to oneself in serial order) has been identified as a key factor in explaining working memory (WM) development. However, the debate remains open with regard to the age at which children are able to use it, and the actual benefits of using such a strategy. Numerous…

Children display an early sensitivity to implicit proportions (e.g., 1 of 5 apples vs. 3 of 4 apples), but have considerable difficulty in learning the explicit, symbolic proportions denoted by fractions (e.g., "1/5" vs. "3/4"). Theoretically, reducing the gap between representations of implicit versus explicit proportions…

Parents are considered a major resource in children's numeracy development. The relative role of cognitive and motivational parenting practices, however, is unclear given that the two types of practices have largely been studied in isolation. The current study simultaneously estimated the contributions of several cognitive and motivational…

The present study examines perceptions of relationship quality as antecedents of best friendship dissolution. Participants included 230 students in Florida (United States; 54.3% girls; ages = 8-13; 39.6% European American, 27.0% Hispanic American, 21.7% African American, and 2.6% Asian American) and 496 students in Lithuania (49.0% girls; ages =…

In line with the reciprocal internal/external frame of reference model (RI/E model), it is well-established that secondary school students generate domain-specific ability self-concepts by comparing their own performance in a domain socially (i.e., with others' performance in this domain) and dimensionally (i.e., with their own performance in…

Irregular words cannot be read correctly by decoding letters into sounds using the most common letter-sound mapping relations. They are difficult to read and learn. Cognitive models of word reading and development as well as empirical data suggest that inhibitory control might be important for irregular word reading and its development. The…

We investigated the effectiveness of a sustained and spiraled content literacy intervention that emphasizes building domain and topic knowledge schemas and vocabulary for elementary-grade students. The model of reading engagement intervention underscores thematic lessons that provide an intellectual structure for helping students connect new…

Deficits in executive function have been associated with internalizing problems in children. Yet little is known about the mechanisms that may explain this association. Using longitudinal data across elementary school years (N = 1,364), this study examined the role of peer difficulty and poor academic performance in understanding longitudinal…

Plausible competing developmental models show similar or identical structural equation modeling model fit indices, despite making very different causal predictions. One way to help address this problem is incorporating outside information into selecting among models. This study attempted to select among developmental models of children's early…

Collaboration is an early emerging component of successful cooperative relations that produces a cascade of positive social preferences between collaborators. Concurrently, robust preferences for affiliated others may restrict these benefits to in-group peers. We investigated how in-group affiliation (based on minimal group markers) and…

The relation to operands (RO) principles describe the relation between operands and answers in arithmetic problems (e.g., the sum is always larger than its positive addends). Despite being a fundamental property of arithmetic, its empirical relation with arithmetic/algebraic problem solving has seldom been investigated. The current longitudinal…