The American family is changing. Divorce, single parents and step-families are redefining the way people live together and raise their children. Is this a change for the worse? David Popenoe sets out the case for fatherhood and the two-parent family as the best arrangement for ensuring well-being and future development of children. His argument has two critical assumptions, which he supports with evidence from a variety of disciplines, including anthropology, biology and history. The first is that children flourish best when raised by a father and a mother with their differing psychological and behavioural traits. The second is that marriage, which serves to hold fathers to the mother-child bond, is an institution to be strengthened if the decline of fatherhood is to be reversed.