Females raise the young in all mammal species. This caretaking is not instinctual but learned. Experiments show that there is no biological “maternal instinct” except just after birth; animals taken from their mothers at birth do not mother their own young. Animals learn to mother: the female characteristic that most people believe is innate is learned. Early human females probably acted like other mammals, like chimpanzee mothers, carrying their babies with them, feeding them from their breasts and sharing solid foods with them. They taught the young survival techniques—which foods we re edible, which animals we re friendly, and where to sleep. Hominid mothers probably made a nest each night to sleep in with their young. Chimp mothers socialize the young, teaching males to share food with adults of both sexes and females to feed their offspring. The mother-child bond constitutes the base of all mammal society, and in some species it is the only society. Prides of lions and herds of elephants are generations of females and their young. Male mammals leave the group voluntarily or by force in adolescence.
From Eve to Dawn - Marilyn French