As humans scattered around the globe, building different societies and novel cultures, they carried something important with them: the seeds of their evolutionary past. Beneath the stunning multicultural rainbow of human diversity and ingenuity that comprise our modern world there lurk universal primal drives. Chapter 4 sets out to explain what they are, and why they endure. Given the importance of reproduction, it's no wonder the devoted pair bond forms the bedrock of every known human society. Based on anthropological research, we travel the world looking for the common threads of human life and sexuality. We touch on the importance of family networks, kinship alliances and nepotism, puberty rites and the incest taboo, and the male role as resource provider, among other human universals. The chapter peers beneath the mantle of political correctness to consider such hot button, cross-cultural issues as rape, abortion and prostitution.

Mating, we learn, is too important to be left to the participants in most world cultures—even today more than half of all marriages are arranged. In fact, hooking up on impulse and falling in love are the new kids on the block. Survival and reproduction are agendas so primal and basic that family, kin and society have always imposed heavily on this most intimate of behaviors. We also explore how feminine mating strategies have solidified and accelerated the flowering of human culture. Courtship rituals may be brutally short or tortuously long, stark proposition or elaborate seduction, but every culture in the world has ended up with exactly the same institution: marriage. Yet in the sprint from dawn of modern civilizations to our own troubled times, the intimate bargain between a man and a woman has been transformed—and shaken to its very foundation.