Two-year-olds are vigilant of others' non-verbal cues to credibility.

Data from three experiments provide the first evidence that children, at least as young as age two, are vigilant of others' non-verbal cues to credibility, and flexibly use these cues to facilitate learning. Experiment 1 revealed that 2- and 3-year-olds prefer to learn about objects from someone who appears, through non-verbal cues, to be confident in performing actions on those objects than from someone who appears uncertain when performing actions on those objects. Experiment 2 revealed that when 2-year-olds observe only one model perform a single action, either confidently or unconfidently, they do not use the model's level of confidence in this single instance to influence their learning. Experiment 3 revealed that 2-year-olds will use a single model's level of confidence to guide their learning if they have observed that the model has a history of being either consistently confident or consistently uncertain. These findings reveal that young children selectively alter their learning based on others' non-verbal cues of credibility, and underscore the importance of an early sensitivity to socio-cognitive cues for human learning and development.