In the mid-1990s, Dr. Marshall Duke and Dr. Robyn Fivush developed a measure called “Do You Know?” It had a series of 20 questions, including: Do you know where your grandparents grew up? Do you know where your mom and dad went to high school? Do you know where your parents met? Do you know an illness or something terrible that happened in your family? Do you know the story of your birth? It turned out that having the answers to these questions was the single best predictor of children’s emotional health and happiness. Children who know more about their families tend to do better when they face challenges, be more resilient, and moderate the effects of stress. Our family’s story—our history—is linked to our own personal identity and knowing that we belong to a larger family. “Children who have the most self-confidence have . . . a strong 'intergenerational self.’ They know they belong to something bigger than themselves,” said Dr. Duke…