The Italian island of Sardinia has more than six times as many centenarians as the mainland and ten times as many as North America. Why? According to psychologist Susan Pinker, it's not a sunny disposition or a low-fat, gluten-free diet that keeps the islanders healthy -- it's their emphasis on close personal relationships and face-to-face interactions. Learn more about super longevity as Pinker explains what it takes to live to 100 and beyond.