The Nature of Love.
In Harlow’s classic experiment, two groups of baby rhesus monkeys were removed from their mothers. In the first group, a terrycloth mother provided no food, while a wire mother did, in the form of an attached baby bottle containing milk. In the second group, a terrycloth mother provided food; the wire mother did not. It was found that the young monkeys clung to the terrycloth mother whether or not it provided them with food, and that the young monkeys chose the wire surrogate only when it provided food. Whenever a frightening stimulus was brought into the cage, the monkeys ran to the cloth mother for protection and comfort, no matter which mother provided them with food. This response decreased as the monkeys grew older.