Walter Francis Willcox, The Philosophical Review (1892)
“ This is not the sexual instinct, for among animals, and quite probably also with primitive man, that instinct is powerful only at certain seasons of the year. Nor is it the social or gregarious instinct, for the anthropoid apes and lowest savages seem to live in families rather than in larger associations, and the scantiness of food probably compels this. It is rather the parental instinct, whereby the male is induced to co-operate with the female in aiding the offspring to survive. ”
