Why are young children so willing to believe what they are told? In two studies, we investigated whether it is because of a general, undifferentiated trust in other people or a more specific bias to trust testimony. In Study 1, 3-year-olds either heard an experimenter claim that a sticker was in one location when it was actually in another or saw her place an arrow on the empty location. All children searched in the wrong location initially, but those who heard the deceptive testimony continued to be misled, whereas those who saw her mark the incorrect location with an arrow quickly learned to search in the opposite location. In Study 2, children who could both see and hear a deceptive speaker were more likely to be misled than those who could only hear her. Three-year-olds have a specific, highly robust bias to trust what people--particularly visible speakers--say.