“I took the hammer and chisels with which I carve my figures from my wet-nurse’s milk,” Michelangelo told his biographer Vasari. With this statement, he was drawing on a long-standing superstition: the belief that breast milk could transmit personality traits. Michelangelo’s wet nurse was the daughter of a stonemason; with her milk, he claimed, he drew in her family’s skill at cutting and carving.
Michelangelo put a positive spin on it, but the belief was a constant source of anxiety in premodern Europe. Were babies sucking in the milk of human kindness, or the milk of vanity, greed, cruelty, and stupidity? As the sixteenth century physician Thomas Muffet wrote:
[N]o man can justly doubt, that a childs mind is answerable to his nurses milk and manners, for what made Iupiter and Aegystus so lecherous, but that they were chiefly fed with goats milk? What made Romulus and Polyphemus so cruel, but that they were nursed by She-wolves? …Is it any marvel also, that Giles the Abbot (as the Saint-register writeth) continued so long the love of a solitary life in woods and deserts when three years together he suckt a Doe?
These myths seemed to come to life in the 1700s, when a feral child was found wandering the woods in Germany, his body covered in matted hair: the result, or so people believed, of suckling from a bear. Milk was dangerous. It could twist a human child into something else.
Where did this fear come from? From the Renaissance through the late 1800s, it was unusual for upper-class European women to breastfeed their own children. Rather, they turned to wet nurses. In an era before reliable infant formula, wet nursing was a lifesaving practice when mothers died in childbirth or couldn’t produce enough milk to feed their infants.
But that’s not why it was so common among the elite. Wet nursing saved time and pain, and it was a status symbol, but more importantly, it prevented elite women from experiencing the contraceptive effects of breastfeeding, allowing them to churn out heir after heir—a valuable form of insurance, considering the high rates of infant mortality. The anxiety about milk carrying personal traits can be read through this lens: the elites feared that the women they employed to raise their children would pass on (what they perceived to be) lower-class characteristics.
Wet nurses had worse things to worry about. As the medievalist Cait Stevenson writes:
Medical thought and popular religious teaching alike forbade women from nursing more than one child at the same time. All these wet nurses… were mothers. They were mothers who weaned their children too early and quickly in order to make some money for the family; they were mothers who lost a child in infancy and had milk but no one suckle; they were mothers sold away from their newborns forever.
Some wet nurses were enslaved. Others were simply disenfranchised. Few had much choice in the matter. Milk traveled up the social ladder, nourishing wealthy children, while the poor ones went hungry. In the words of the sixteenth-century French essayist Michel de Montaigne:
For a very little profit, we every day tear their own children out of the mothers’ arms, and make them take ours in their room: we make them abandon their own to some pitiful nurse, to whom we disdain to commit ours, or to some she-goat.
Yet in other parts of the world, wet-nursing took a very different form. Consider the Mughals. A Mughal prince could have two families: one bound together by ties of blood, the other by ties of milk. His blood family came from his birth parents, his milk family from his wet nurse.
The social structure derived from Islamic law, which considers babies fed at the same breast to be “milk-siblings,” equivalent in many ways to blood siblings. Wet-nursing, therefore, created a lifelong bond, not just between the child and the nurse, but between the child and the nurse’s entire family.
While Mughal prince’s blood brothers were likely to be his rivals for status and power; his milk brothers, coming from lower-status households, had everything to gain from his success. Ties of milk proved to be stronger than ties of blood.