 Depression and isolation are some of the worst conditions a social creature can endure. This is why it is such a potent punishment in prisons of both past and present. Today we return to Harry Harlow and his pivot in career from studying love to studying depression. In his previous 1958 paper Harlow outlined the effects on infant rhesus monkeys, which were removed from their biological mothers at birth to be reared using surrogate cloth and wireframe mothers. The experiment created socially and emotionally stunted test subjects, but showed that bonds can be created even with a bare bones maternal figure. But as Harlow's personal life started to have issues, so would the cruelty of his experiments, by attempting to create depression in his subjects. His partial and total isolation studies would take Harlow's experiments one step further, completely removing any parental figure from the lives of the infant rhesus monkeys. The experiments would garner even more criticism compared to his earlier mother studies, and would ultimately lead to an apparatus called the pit of despair. My name is John and welcome back to the dark side of science. Our story starts in the wake of Harry Harlow's monkey mother experiments. By the late 1950s, his primate laboratory had become a controversial, but generally accepted part of the University of Wisconsin Madison. Sure, the studies involved separation of infant rhesus monkeys from their mothers at a young age, which most would consider cruel, but at least important discoveries were made. Harlow had touched upon isolation studies during his nature of love experiments, where infant monkeys were given an inanimate cloth or wire mother as the only form of social interaction. The surrogate mother offered at least something in terms of company, but Harlow wanted to go deeper into the isolation side of the experiment. Starting off in 1959, Harlow devised the first of his social isolation experiments. The concept was pretty simple and made use of an empty YK that allowed the subjects to see, hear and smell their peers, but not be able to make physical contact. This was named by Harlow as the partial isolation study and sought out to observe the social effects on withholding physical contact. During the 1960s, Harlow and his colleagues published several papers on the subject of partial isolation. In 1965, a study looked at comparing one and three-year-old rhesus monkeys in social isolation alongside non-isolated control subjects. They found that the partial isolates exhibited greater clutching and chewing behaviour, as well as showing greater anxiety. The study showed that partial isolation didn't affect the subject's intellectual development, but their social maturity was very much stunted. In a 1971 paper, Harlow summarised the decade of partial isolation experiments and set up another partial isolation study involving 48 subjects, 24 male and 24 female. The ages observed ranged between 3 months and 13 and a half years. Each subject had been raised in partial isolation taken from their mothers as early as possible. This meant that the oldest of the subjects had spent over a decade in partial isolation. They divided the participants into four groups of six males and six females, zero to two years old, pre-adolescents, two to five years old, adolescents, five to ten years old, early adulthood and ten to thirteen years old, late adulthood. To act as a control group, 12 feral resus monkeys were employed. Before the experiment, most of the subjects had been housed in small 2.5 feet wide wire mesh cages. The control group were monkeys captured from India and shipped to the laboratory. They too were partially isolated for a similar amount of time and in some cases over years, but had been born and raised in the wild. Thus, they had experienced a natural social upbringing before captivity. They found that the laboratory raised subjects showed less social maturity and the older the group, the more introverted they became. Even when compared to the control group, similar aged and isolated feral monkeys were shown to be more active and exhibited less external signs of anxiety. The results, although pretty predictable, I mean if you isolate a person they become less adept at social interaction were not enough for Harlow and because of this, he sought out to take his experiments to see what would happen under total isolation conditions. Whilst a partial isolation studies played out, Harlow started looking at a concept for a total isolation experiment. He devised an isolation chamber where the resus monkey would be placed, the chamber was always lit, had some moving around space and most crucially was not designed to invoke any sensory deprivation apart from social interaction. To reduce the risk of noise from the outside, a white noise generator was used to mask any ambient sounds. The subjects were isolated from human and monkey alike, observations were made by one-way vision slits and a test area. In a 1965 paper on the total isolation studies, Harlow describes the experiment set up. Three groups of newborn monkeys were isolated in individual chambers for three, six and twelve months respectively. In addition, one group was kept in partial isolation in individual cages in a laboratory nursery for the first six months, then placed in the isolation chamber for six months. There were six monkeys in the three month group and four monkeys in each other of the groups. Mental ability tests were undertaken during their isolation to map their intelligence. To measure the difference in social development between the partially and totally isolated, Harlow paired up monkeys that had been in the study for the same amount of time. For example, two from the three month total isolation group were paired with two from the partial isolation group. All the monkeys were of the same age and were released into a playroom scenario. The four monkeys were allowed to be in a room for 30 minutes, five days a week for 32 weeks. But these young fully isolated monkeys being placed with others was a complete sensory overload and nearly all went into shock showing anxious body language such as self-clutching. Two of the monkeys in the three month isolation group refused to eat were moved to the integration phase of the experiment. One sadly would die after five days. The other was force-fed and subsequently survived. Although severely socially affected, the three month group did show signs of being able to recover, gradually improving after each session playing with their control group, but that was the most positive of outcomes. It only got worse with the next group. The six month isolated monkeys were split into two groups, one of which were isolated straight away whereas the other was isolated after six months of partial isolation. They, after being introduced with the control monkeys, would avoid all contact and play. The three month group would engage with play fighting after a few days, but this was not observed with the six month subjects. The late six month group, the subjects who were initially partially isolated showed a better ability to interact with the control group, albeit only in the form of aggression. But the 12 month isolated monkeys, there were no signs of interest in themselves or their control playmates. In Harlow's own words, 12 months almost obliterated the animals socially. In contrast, the controls were pretty quickly playing and enjoying their social interactions amongst one another. In follow up sessions post 32 weeks, the three month group had seemed to have adjusted relatively well. The six month had some improvements but were socially stunted and the 12 month group were completely ruined. Now this study was yet again like before a stepping stone down the stairs to hell as Harlow looked to extend his experiments into the examination of depression. Harlow throughout his life was susceptible to depression periods, usually only lasting a few days, and was fuelled by drink, stress and a constant fear of failure. As his symptoms got worse throughout the 1960s, so did his experiments. He saw in his isolated monkeys, especially the 12 month subjects, the signs of depression as they rocked back and forth, staring off into the distance, refusing to interact with their peers. Harlow thought that this could be used in the path of understanding the condition and maybe even find a cure. He would require a reliable method of creating a depressive state, and that leads us on to the next stage of Harlow's progressively cruel series of experiments. Harlow would experience his worst depressive phase so far in his life in the last years of the 1960s. His second wife Margaret was diagnosed with breast cancer in 1967, and this understandably played on the scientist's mind. Harlow's career was at its peak, but his anxiety about his wife and the fear of failing at the zenith of his life's work sent him into an aspiring depression. Before, his bouts of depression rather strangely had been set off by any accolades achieved for his research, and in 1967 it was no different. He had won the National Medal of Science given by Lyndon B Johnson no less, but the rest of the year he couldn't shake his depressive state, but unlike before, it would last more than just a few hellish days. He would be admitted to the Mayo Clinic in March 1968. Here he would receive electroshock therapy, and although initially reluctant, Harlow would later admit that his recovery was good. After 59 days, Harlow was discharged, and he returned back to his primate lab. He noted his feelings of isolation during his stay, but his experience inspired Harlow to delve into depression, and he did this by the only way he knew how, by terrorizing resus monkeys. He knew from previous studies that six or more months of total isolation created depression like symptoms in his monkeys. Harlow had also dabbled in age-mate separation, where two monkeys were allowed to bond with one another only to be separated. In Harlow's own words, the fact that these behaviors did not extinguish within the sixth month period attest to the punishing pain of separation and the vigor and violence of protest. He wanted a surefire way to crush the spirit of any subject, ideally quicker than the six-month needed from total isolation. This is where the pit of despair comes into our story, although officially it was referred to as a vertical chamber. In a 1974 paper by Harlow and one of his students, Stephen J. Soumy, the pit of despair was outlined in the use to create depression in monkeys over several previous experiments. The vertical isolation chamber initially conceived in 1969 was constructed of a stainless steel trough with sloping down sides. This was to create a trapped feeling by reducing the subject's ability to climb. The chamber was dark with the only light coming from the top which was almost impossible to reach. It had a three-eighths inch wire mesh floor one inch above the bottom of the chamber to allow waste material to drop through the drain and out of holes drilled in the stainless steel. The chamber also had a food box and a water bottle holder thus stopping any interaction with the outside world. Harlow would later describe the design's intent being in the depths of despair, sunken in a way of loneliness, helplessness and hopelessness. The first test study took place in 1971 when four monkeys ranging in age between 6 and 13 months old were placed in their own pit for 30 days. All four showed immense psychological damage upon release. In 1971 his wife's cancer progressed and would subsequently end in her death that year which no doubt added to Harlow's depression. Harlow and Soumy would continue with a more formal study in 1972. This again would involve four monkeys being placed in the chamber at 45 days old for a period of 45 days. After removal from the chamber the subject exhibited intensive self-clasp and self-huddling coupled with low levels of movement and environmental exploration. The difference was night and day between them and their control subjects who were partially isolated but allowed to socialize. Harlow found that even a year after their isolation his subjects still showed signs of depression and severe social stunting. The next study using the pit was also in 1972 and took eight monkeys at the age of three and split them up into two groups of four. These groups were then placed in a social housing cage together for four weeks. One group was taken and placed in separate cages for nine days then placed in the pit. Harlow wanted to see if he could create depression in otherwise well-adjusted and healthy monkeys. You see all eight have been raised by their mothers and have been well socialized. The sentence for the test group was 10 weeks in the vertical chamber. After removal from the chamber the monkeys were observed. Severe clinging and lack of movement were noted. It seemed that the chamber could guarantee a depression like state in Harlow's monkeys and this seemed to follow his personal life. Strangely in 1972 Harlow remarried his first wife. It could be inferred that the creativity of the cruelty increased as Harlow's personal life became ever more complicated. But Harlow wasn't just creating loads of depressed monkeys for no reason. His parent plan was to try and rehabilitate his subjects. Initially his total isolated monkeys would be introduced to his cloth mothers and during off the body contact they provided showed some signs of rejuvenation. Next he attempted to see if real monkey contact could work. But there was a problem. His subjects wouldn't initiate contact instead preferring to hold themselves in a corner. But Harlow had an idea. This came in the form of therapy monkeys. He had seen in previous studies that infants of dysfunctional monkey mothers were very clingy. He thought that maybe this could be harnessed in bringing around his depressed subjects. The young therapy monkeys from dysfunctional mothers were introduced to some six month isolates. Like he predicted the therapists clung to the isolates and in a later observation were found to almost be normal within a year. But this would not be the case of the pit of despair candidates. Now Harlow would retire from the University of Madison Wisconsin in 1974 leaving the task of continuing his work with his old students such as Sumi. The regularity of Harlow and his team's publication of their work allowed their studies to be followed at the time quite closely. As such the cruelty of the experiments received criticism at the time. Even some of Harlow's own students were concerned with the increasing cruelty of the pit of despair experiments. It wasn't helped by Harlow's ability to use shocking language to describe his experimental devices. Originally he wanted to call the vertical chamber the dungeon of loneliness. Harlow's studies can largely be regarded as questionable as the way a resus macaque experiences depression or any other psychological condition for that matter is very different and hard to translate to humans. Also it does seem pretty obvious if you lock up a largely social animal in total isolation for extended periods of time from young ages that they would exhibit developmental difficulties. Now where would you rate this subject on my ethical scale? I'm going to say around a six or a seven. This is a plain difficult production. All videos on the channel are creative commons attribution share alike licensed. Plain difficult videos are produced by me John in the currently sunny southeastern corner of London UK. Help the channel grow by liking commenting and subscribing. 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