Anyone who has been around young children knows that they are inquisitive. They are constantly exploring and trying new things. They ask a lot of questions – indeed some research has shown that by the time they are in preschool, they ask about 72 questions per hour – or over one per minute! Young children’s inquisitiveness is one reason they acquire so much information so quickly. Indeed, research in cognitive development has revealed that young children learn in similar ways to scientists. They generate theories about the world, test those theories, and revise them as they encounter new data. Yet neither children, nor scientists work in isolation. They question their peers and together through conversations refine their ideas. Our book, The Questioning Child, investigates how children develop this remarkable ability to use questions as a mechanism for knowledge acquisition. Questioning is a remarkable ability because it allows learners to highlight areas of uncertainty and thus signal to others what they do and do not understand and, as a result, it allows learners to quickly and efficiently benefit from other people’s knowledge. Yet surprisingly, we know very little about how a questioning stance develops, nor how that development is influenced by children’s home and school experiences. Moreover, questions are not just a means to gain information, they can also be used to help others reason and learn. Such pedagogical questions have been used for millennia by teachers to help pupils deepen their understanding of a particular topic. Recall Socrates and his many dialogues. Again, we are just beginning to understand why the Socratic method is so effective. Our book, The Questioning Child: Insights from Psychology and Education, brings together researchers from developmental psychology, cognitive science, and educational science, all of whom are working on questioning. The book provides readers with the latest science on this topic, with the goal of prompting others to tackle this understudied topic. In exploring research from the book, we hope that the reader comes to the same conclusion as we did: Children and adults’ questions matter deeply for cognitive development. Children’s questions allow children to gain valuable information. Adults’ questions scaffold children’s discovery and learning.