Geometry is one of the highest achievements of our species, but its foundations are obscure. Consistent with longstanding suggestions that geometrical knowledge is rooted in processes guiding navigation, the present study examines potential sources of geometrical knowledge in the navigation processes by which young children establish their sense…

When students learn scientific theories that conflict with their earlier, naive theories, what happens to the earlier theories? Are they overwritten or merely suppressed? We investigated this question by devising and implementing a novel speeded-reasoning task. Adults with many years of science education verified two types of statements as quickly…

It is commonly assumed that artifacts are named solely on the basis of properties they currently possess; in particular, their appearance and function. The experiments presented here explore the alternative proposal that the history of an artifact plays some role in how it is named. In three experiments, children between the ages of 4 and 9 years…

Young children reliably distinguish reality from fantasy; they know that their friends are real and that Batman is not. But it is an open question whether they appreciate, as adults do, that there are multiple fantasy worlds. We test this by asking children and adults about fictional characters' beliefs about other characters who exist either…

Examined how 3- and 5-year-olds and adults extend names for human-made artifacts. Found that even 3-year-olds were more likely to provide artifact names (e.g., "knife") when they believed objects were intentionally created and to provide material-based descriptions (e.g., "plastic") when they believed objects were accidentally…