Harry Frederick Harlow
Two groups of baby rhesus monkeys were removed from their mothers. In the 1st group, a terrycloth mother provided no food, while a wire mother did, in the form of an attached baby bottle containing milk. In the 2nd group, a terrycloth mother provided food; the wire mother didn't. It was found that the young monkeys clung to the terrycloth mother whether or not it provided them with food & that the monkeys chose the wire surrogate only when it provided food. Whenever a frightening stimulus was brought into the cage, monkeys ran to the cloth mother, no matter which mother provided food. This response decreased as they grew older. When they were placed in an unfamiliar room with their cloth surrogate, they clung to it until they felt secure enough to explore. Once they began to explore, they occasionally returned to the cloth mother for comfort. Monkeys placed in an unfamiliar room w/out their cloth mothers acted very differently. They froze in fear & cried, crouched down or sucked their thumbs. Some even ran from object to object, apparently searching for the cloth mother, as they cried. Monkeys placed in this situation with their wire mothers exhibited the same behavior as the monkeys with no mother. Once they reached an age where they could eat solid foods, they were separated from their cloth mothers for three days. When they were reunited with their mothers, they clung to them & didn't venture off to explore as they had in previous situations. Harlow concluded from this that the need for contact comfort was stronger than the need to explore. The study found that monkeys who were raised with either a wire mother or a cloth mother gained weight at the same rate. However, the monkeys that had only a wire mother had trouble digesting the milk & had diarrhea more frequently. Harlow's interpretation of this behavior, still widely accepted, was that a lack of contact comfort is psychologically stressful to the monkeys., The importance of these findings is that they contradicted both the then common pedagogic advice of limiting or avoiding bodily contact in an attempt to avoid spoiling children & the insistence of the then dominant behaviorist school that emotions were negligible. Feeding was thought to be the most important factor in the formation of a mother-child bond. Harlow concluded, however, that nursing strengthened the mother-child bond because of the intimate body contact that it provided. He described his experiments as a study of love. He also believed that contact comfort could be provided by either mother or father. This idea was revolutionary at the time., Harlow 1st reported the results of these experiments in "The Nature of Love", the title of his address to the 66th Annual Convention of the American Psychological Association, 8/31/58.
Psychology
Learning to Love