Children acquire information, especially about the culture in which they are being raised, by listening to other people. Recent evidence has shown that young children are selective learners who preferentially accept information, especially from informants who are likely to be representative of the surrounding culture. However, the extent to which children understand this process of information transmission and actively exploit it to fill gaps in their knowledge has not been systematically investigated. We review evidence that toddlers exhibit various expressive behaviors when faced with knowledge gaps. They look toward an available adult, convey ignorance via nonverbal gestures (flips/shrugs), and increasingly produce verbal acknowledgments of ignorance ("I don't know"). They also produce comments and questions about what their interlocutors might know and adopt an interrogative stance toward them. Thus, in the second and third years, children actively seek information from interlocutors via nonverbal gestures or verbal questions and display a heightened tendency to encode and retain such sought-after information.
Keywords: children; communication; ignorance; questions.