Part 2 — Introductory material

Retrogression in fatherhood—Among mammals no examples of devoted fathers—Egoistic desires increase in the males and interest in the family decreases—Probable reason—Method of birth and circumstances of life of infant mammals force mothers to monopolise nutrition and care of young—Parenthood more automatic—The father pushed out of his earlier position of service to the family—Instead of a working partner with the mother he becomes a member apart—His character appears to change—He becomes masterful, pugnacious and jealous—This general among mammals—Number of young among mammals usually reduced—Varied forms of sexual association practised by different species—Polygamy frequent—The matriarchal family—The clue we are seeking—The egoism of the males acts for the advantage of the females—The maternal instinct fixed in the mothers—Self-sacrifice becomes once and for ever the supreme joy and privilege of the female—Objections that may be raised—Resumé—General conclusions to be drawn from pre-human parenthood.