"What if I was to tell you that a game of peek-a-boo could change the world?" asks seven-year-old Molly Wright, one of the youngest-ever TED speakers. Breaking down the research-backed ways parents and caregivers can support children's healthy brain development, Wright highlights the benefits of play on lifelong learning, behavior and well-being, sharing effective strategies to help all kids thrive by the age of five. She's joined onstage by one-year-old Ari and his dad, Amarjot, who help illustrate her big ideas about brain science.