Motherhood and the Relationships of the Sexes
Two things I have been anxious to bring out prominently in the foregoing chapters: that parental behaviour among the insects, reptiles and fishes presents us with a bewildering diversity of aspects—in particular, that the instinct of caring for the young is not fixed in the mother, but may be transferred from her to the father; and further, that all parental sacrifice, though often unconsciously expended to maintain the well-being of the family, is of direct benefit to the parent who bestows it, and is the surest means of developing and brightening such a parent’s individual intelligence.