This is a book about personality and intelligence. Personality is what a person typically does, thinks, and feels. Intelligence is what a person is cognitively capable of. How are personality and intelligence related, and why? Using data from millions of individuals and thousands of studies from around the world, we examine their components at an unprecedented level of depth to uncover hidden connections between these fundamental domains of human individuality. Viewing the panorama of their links illuminates constellations of personality traits and abilities that guide our behavior as we traverse ever-changing environments. These patterns harken back to our evolutionary roots and have profound implications for humanity's present and future. From your own life to diverse societies to the future of our species, this book illuminates deep truths about who we are and why we are.