Focusing on the series of conflicts present between mother and father, between parent and child, and between children, the author follows up the ideas from "Sperm Wars", his investigation into the evolutionary biology of conception. Discomfort of pregnancy, child abuse, sibling rivalry, incest, arranged marriage, child fostering, adoption, and the trials of adolescence, are all deviations from the cliched dream of the contented nuclear family. As seen by Baker, all these situations generate their own particular Darwinian benefits and problems. Here he dramatizes these events and then explains the evolutionary biological behaviour of each of the characters.