The ready availability of donated sperm and eggs has made possible an entirely new form of family. Children of the same donor and their families, with the help of social media and the internet, can now locate each other and make contact. These genetic strangers, along with the donor, sometimes form meaningful connections that blossom into lively and longstanding groups who maintain a Facebook page, hold regular reunions, and enjoy close friendships. This book is about these unprecedented families, networks of strangers linked by genes, medical technology, and intense curiosity. Based on over 350 interviews with children and parents from all over the United States, Rosanna Hertz and Margaret K. Nelson explore what it means to be a donor sibling and what it's like to be a parent who discovers four, six, or even a dozen children who share half the DNA of their offspring. Random Families chronicles the chain of choices that couples and single moms make-from how to conceive, how to accept donors into their family trees, and what to do when they discover that other children share half their child's DNA. Do shared genes make you family? Do kids find anything in common? What becomes of the chance networks that arise once parents and donor siblings find one another? Hertz and Nelson trace what happens in these groups over time and reveal the different motivations both kids and parents have for becoming part of them.Random Families shares how these remarkable relationships, woven from bits of information, are transformed into new possibilities for kinship. The authors offer a highly readable account of life at the intersection of reproductive technology, social media, and the human desire for intimacy and identity.