Children ages 18 and 24 months were assessed for the ability to understand and learn from an adult's nonverbal expression of agreement and disagreement with a speaker's claims. In one type of communicative exchange, a speaker made 2 different claims about the identity or location of an object. The hearer nodded her head in agreement with one claim…

Four-year-olds, 6-year-olds, and adults were asked to make judgments about the reality status of four different types of machines: real machines that children and adults interact with on a daily basis, real machines that children and adults interact with rarely (if at all), and impossible machines that violated a real-world physical or biological…