Messing with our heads

[Jan Klimkowski]

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.

When the monkeys 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 without their cloth mothers acted very differently. They froze in fear and cried, crouched down, or sucked their thumbs. Some even ran from object to object, apparently searching for the cloth mother, as they cried and screamed. Monkeys placed in this situation with their wire mothers exhibited the same behavior as the monkeys with no mother.

Once the monkeys 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 and did not 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 and suffered from diarrhea more frequently. Harlow's interpretation of this behavior, which is still widely accepted, was that lack of contact comfort was 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 and the insistence of the then dominant behaviorist school of psychology 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. Though widely accepted now, this idea was revolutionary at the time.

Critics of Harlow's research have observed that clinging is a matter of survival in young rhesus monkeys, but not in humans, and have suggested that his conclusions, when applied to humans, overestimate the importance of contact comfort and underestimate the importance of nursing.[3]

Harlow first reported the results of these experiments in "The nature of love," the title of his address to the sixty-sixth Annual Convention of the American Psychological Association, Washington, D.C., August 31, 1958.

From around 1960 onwards, Harlow and his students began publishing their observations on the effects of partial and total social isolation. Partial isolation involved raising monkeys in bare wire cages that allowed them to see, smell, and hear other monkeys, but provided no opportunity for physical contact. Total social isolation involved rearing monkeys in isolation chambers that precluded any and all contact with other monkeys.

Harlow et al. reported that partial isolation resulted in various abnormalities such as blank staring, stereotyped repetitive circling in their cages, and self-mutilation. These monkeys were then observed in various settings. Some of the monkeys remained in solitary confinement for 15 years.[4]

In the total isolation experiments baby monkeys would be left alone for three, six, 12, or 24[5][6] months of "total social deprivation." The experiments produced monkeys that were severely psychologically disturbed. Harlow wrote:

No monkey has died during isolation. When initially removed from total social isolation, however, they usually go into a state of emotional shock, characterized by ... autistic self-clutching and rocking. One of six monkeys isolated for 3 months refused to eat after release and died 5 days later. The autopsy report attributed death to emotional anorexia. ... The effects of 6 months of total social isolation were so devastating and debilitating that we had assumed initially that 12 months of isolation would not produce any additional decrement. This assumption proved to be false; 12 months of isolation almost obliterated the animals socially ...[1]

The pit of despair is a colloquial term for the vertical chamber apparatus, a device used in experiments conducted on rhesus macaque monkeys during the 1970s by American comparative psychologist Harry Harlow and his students at the University of Wisconsin-Madison.[1] The term was first used by Harlow himself to describe his intentions for its use, and was subsequently adopted by critics of his research. The aim of the research was to produce an animal model of human clinical depression.

The vertical chamber was little more than a stainless-steel trough with sides that sloped to a rounded bottom. A 3/8 in. wire mesh floor 1 in. above the bottom of the chamber allowed waste material to drop through the drain and out of holes drilled in the stainless-steel. The chamber was equipped with a food box and a water-bottle holder, and was covered with a pyramid top [removed in the accompanying photograph], designed to discourage incarcerated subjects from hanging from the upper part of the chamber. [2]

Harlow placed baby monkeys in the chamber alone for up to one year. Within a few days, they stopped moving about and remained huddled in a corner. The monkeys were found to be psychotic when removed from the chamber, and most did not recover.

Harry Harlow was also, visibly, from time to time, the US Army's Head of Human Resources Research and a consultant to the US Army Scientific Advisory Panel.

Let's just break that down. There were periods when Harlow officially ran the US Army's scientific research into "human resources"?

Monkeys?

Yes. And more.