Dr. Harry Harlow was trying to understand the meaning of human relationships and love, by focusing on the relationship between a mother and a baby. He separated an infant monkey away from its mother since birth, later he arranged for two artificial mothers to be placed in with the baby monkey. The first was a wired mother that feeds it and the second a cloth mother that doesn’t. We realize the monkey ran to the wired mother but quickly left and ran to the clothed mother spending a lot of time clinging to it.
This experiment showed that infant love isn’t based on psychological need or nursing, but about attachment and providing protection. (Harry F. Harlow 1958) Harlow’s monkeys proved that “better late than never” was not a slogan applicable to attachment. When Harlow placed his subjects in total isolation for the first eight months of life, denying them contact with other infants or with either type of surrogate mother, they were permanently damaged. Harlow and his colleagues repeated these experiments, subjecting infant monkeys to varied periods of motherliness. They concluded that the impact of early maternal deprivation could be reversed in monkeys only if it had lasted less than 90 days, and estimated that the equivalent for humans was six months.
After these critical periods, no amount of exposure to mothers or peers could alter the monkeys’ abnormal behaviors and make up for the emotional damage that had already occurred. (Harry F. Harlow ,1959)