The biological world includes many negatively valenced activities, like predation, parasitism, and disease. Do children's books cover these activities? And how do parents discuss them with their children? In a content analysis of children's nature books (Study 1), we found that negatively valenced concepts were rarely depicted across genres and…

Given limitations in the integrative scope of past research, basic questions about the organization and development of preschoolers' living kinds concept remain open to debate. This study was designed to address past limitations through use of a longitudinal design, extensive stimulus set, and alternate indices of understanding. Thirty-five…

Children's developing reasoning skills are better understood within the context of their social and cultural lives. As part of a research-museum partnership, this article reports a study exploring science-relevant conversations of 82 families, with children between 3 and 11 years, while visiting a children's museum exhibit about mammoth bones, and…

Three hundred and forty-one children (M[subscript age] = 9,0 years) engaged in a series of science tasks in collaborative, same-sex pairs or did not interact. All children who collaborated on the science tasks advanced in basic-level understanding of the relevant task (motion down an incline). However, only boys advanced in their conceptual…

Two experiments examined the possibility that children and adults possess a single-object/single-motion intuition. This intuition involves the view that all parts of a rigid object must move at the same speed because they all move together. (RH)

Three experiments examined 3- to 11-year-olds' understanding of entropy, asking whether undifferentiated forces, such as the wind or objects being thrown into the air, could create order or disorder in a set of objects. Found that even 4-year-olds were sensitive to asymmetrical effects of such events. Older children applied this principle more…

Findings obtained from 90 first- through fifth-grade children indicate that children grasp the direct relationships between speed and distance and between duration and distance before they grasp the inverse relationship between speed and duration--a finding which may represent a general principle of cognitive development. (Author/RH)

Two studies explored how mothers and preschoolers talk and reason about events in which biological and nonbiological objects change in size. Analysis of conversations indicated that although mothers discussed events primarily in domain-specific ways when using the term growth, they exhibited some domain blurring in explanations to preschoolers.…

A buoyancy prediction test was developed to access preschoolers' early understanding of density. Two- to five-year-olds and college students make predictions about the buoyancy of a set of objects that varied in density, weight, and volume. Found that children aged four and five demonstrated patterns of judgment similar to those of the college…