Looking through the vast catalog of human diversity that he found on a dating website, neuroscientist David Linden got to wondering: What makes us all so different? Exploring everything from the roots of sexuality, gender, and intelligence to whether we like bitter beer, Linden shows how our individuality results not from a competition of nature versus nurture, but rather from a mélange of genes continually responding to our experiences in the world, beginning in the womb. And in this accessible guide to human complexity, he shows why individuality matters, as it is our differences that enable us to live together in groups.