The development of math reasoning and 3-d mental rotation skills are intertwined. However, it is currently not understood how these cognitive processes develop and interact longitudinally at the within-person level -- either within or across genders. In this study, 553 students (52% girls) were assessed from fifth to seventh grades on 3-d mental…

Recent evidence in adults indicates that object perceptual processing is affected by the competition between action representations. In the absence of a specific motor plan, reachable objects associated with distinct structural (grasping) and functional (using) actions (e.g., calculator) elicit slower judgments than objects associated with similar…

The statistical properties of data are not present in any individual value, but rather, emerge only by perceiving the set as a whole. Summarizing the statistical properties of sets (e.g., creating ensembles) is ubiquitous in cognition, yet one unanswered question is how this process changes over development. The properties of number sets (e.g.,…

Previous studies provided evidence of a relationship between mental rotation (MR) and motor processes in children and adults. However, there is no direct evidence that MR ability is a reliable predictor of success for motor performance. After completion of a MR test, the motor performance of 7- to 8-year-old and 11- to 12-year-old children was…

Numerical estimation has been used to study how children mentally represent numbers for many years (e.g., Siegler & Opfer, 2003). However, these studies have always presented children with positive numbers and positive number lines. Children's mental representation of negative numbers has never been addressed. The present study tested children…

In everyday life, we use folk theories about the mind and behavior to understand ourselves and others. An important part of our folk theory of mind is our intuitions about the role of the self in mental functioning--namely, whether the self is able to control each mental operation. The current study explored beliefs about the nature of control…