Theres’s no question that in the past, psychology and biology research wasn’t…ethical. Since then, research ethics has become an area of focus and is expected when any experiment is run.
In the 1950s, people didn’t quite understand “love” and “attachment.” Harry Harlow, an American psychologist, decided to test what love and dependence is all about, using Rhesus monkeys as his test subjects. What came out of his research was both defining and concerning.
An interesting book is Wire Mothers & Inanimate Arms: Harry Harlow and the Science of Love by Jim Ottaviani and Dylan Meconis. In the book they describe Harry Harlow’s work and experimentation on love, security, attachment, and development.
I will begin by saying that there is good that came out of Harlow’s experiments on the monkeys: because of the outrage sparked by his work, there was reform in the United States towards animal rights, and towards more standardization of ethical standards of experiments conducted in the US. (Yes, his experiments were that bad).
Harlow conducted his work at the University of Wisconsin-Madison. He was studying social behaviors, social isolation, and maternal dependence. What he did was to utilize the “pit of despair”, where baby monkeys were separated from their mothers and left in the pit for up to one year after birth. Or if not left for a full year after birth, they were isolated frequently from the other monkeys.
Of course, these animals became good models of depression.
Harlow wrote, “One of six monkeys isolated for three months refused to eat after release and died five days later…the effects of six months of total social isolation were so devastating and debilitating that we had assumed initially that twelve months of isolation would not produce any additional decrement. This assumption proved to be false; twelve months of isolation almost obliterated the animals socially.”
He also wrote, “These monkeys suffer total maternal deprivation and, even more important, have no opportunity to form affectional ties with their peers.”
Yes, this was actually written in a scientific journal article. In fact, the article can be found here.
The paper, Total Social Isolation in Monkeys, (whom Harlow wrote with his second wife, Margaret, and Robert O. Dodsworth. Now, I’m one for juicy relationship gossip: apparently, Margaret was Harry’s second wife. He was married to a Clara first, who was once his student, no less, then the couple divorced. That same year, Harry married Margaret. Margaret then died of cancer, and Harry remarried his first wife Clara), described Harlow’s experimentation history. The paper described briefly that for the past ten years (the paper was published in 1965), Harlow and his team were studying the effects of partial isolation. What they did was to raise monkeys from birth and onward in wire cages with no stimulation or toys or much of anything:
(Figure 1 from Total Social Isolation in Monkeys)
The monkeys therefore suffered total maternal separation and had no opportunities to form ties with their peers. What the team found was that these monkeys were aggressive and hostile, not only to others, but towards their own bodies. They engaged in “repetitive stereotyped movements”, were detached from their environment, and were unable to form heterosexual attachments with other monkeys, even when given the opportunity to do so during preadolescence, adolescence and adulthood.
In the paper, Total Social Isolation in Monkeys, the team sought to go one step further: partial social isolation was no longer enough. Total social isolation was now the name of the game.
The total isolation was achieved by housing the monkeys only a few hours after their birth in stainless-steel chambers, like this one:
(Figure 2 from Total Social Isolation in Monkeys)
The monkeys were isolated in these chambers until 3, 6, or 12 months of age. During the periods, the monkeys had no contact with any other animal, including humans. Harlow added, however, that no sensory deprivation was maximized. The chamber was also lighted, was allowed to emit sounds, and allowed for “adequate opportunities for cutaneous-proprioceptive expression and exploration”.
However, the area beyond the cage was sound-masked by a white-noise source. Loud noises from the corridor beyond the cage, though, was found to produce attentive, or even freezing responses, in the monkeys.
While running these conditions, Harlow also had another group of monkeys kept in partial isolation in individual cages for the first 6 months after birth. They were then placed in the total isolation chambers for another 6 months.
If anything, Harlow was detail-oriented and determined to not let confounds in his experiment. As horrible as the experiments were, you have to agree that Harlow was thorough.
The effects of isolation were measured by “comparing the social behavior of pairs of isolated monkeys after release from the chambers with that of pairs of equal-aged monkeys raised in partial isolation.”
Now, again, he was rather thorough, though I do think he should have also compared the behaviors of those animal pairs to monkey that had suffered no sort of isolation. That would have been the best control, in my mind.
The four monkeys who suffered isolation, either partial or total, were tested as a group of four in playroom situations, like the one here:
(Figure 3 from Total Social Isolation in Monkeys)
The four monkeys were let out for thirty minutes per day, for 5 days a week. This part of the experiment ran for 32 weeks.
Harlow even went so far as to test long-term effects by assessing the behaviors of the monkeys from 1 to 2 years after the “termination of isolation.” Two observers then recorded the occurrence of preselected behaviors and social interactions.
The monkeys’ intellectual developments were also tested by utilizing learning tests, including “discrimination, delayed response, and learning-set formation.”
Again, he was rather thorough. I do have to admire his creativity and detail-orientation as a scientist.
In case you were wondering if any monkeys died, Harlow kindly mentioned in his paper that “No monkey has died during isolation”.
However, when the animals were pulled out from their isolation, they usually went into “a state of emotional shock, characterized by the autistic self-clutching and rocking…” An image of this behavior was provided in the paper:
(Figure 4 from Total Social Isolation in Monkeys)
One of the six monkeys that had been isolated for 3 months refused to eat. The monkey died 5 days later. So, yes, there were deaths, but not in the isolation chambers. The paper stated that the autopsy report “attributed death to emotional anorexia”.
A second animal might have also died of refusing to eat, but the team intervened and force-fed the animal. Harlow mentioned that the refusal to eat did not appear in the 6 or 12 month groups.
Some of the results indicated in the paper were that the effects of social isolation for three months are reversible, though dramatic. The paper also stated that is there is any “long-term social or intellectual damage, it eludes our measurements. Given the opportunity soon after release to associate with controls of the same age, these short-term isolates start slowly during the first week and then adapt and show the normal sequence of social behaviors.”
Somehow, I find that hard to believe, that none of the effects are long-term damaging, but that’s what the paper says, and who am I to question Harlow? And maybe indeed the monkeys do recover fully. It’s certainly in the realm of possibility. Humans have shown that, like children reared in unhealthy orphanages but then pulled out no later than their first year of life. They tend to do well, I believe. So perhaps Harlow’s conclusions were correct, though, truth be told, I still have my misgivings.
However, those monkeys who were isolated for 6 months, were severely impaired in their ability to socialize, and these monkeys were more easily threatened. These monkeys, unlike the 3-month isolation cohorts, did not engage in rough-and-tumble play, or any sort of play for that matter. “Social interaction throughout the entire 32-week test period…was for all practical purposes nonexistent except for bursts of aggression which the controls occasionally directed toward the isolate animals.”
I find it interesting that the controls were hostile towards the isolates. It almost makes sense evolutionarily: why keep around those who are least likely to benefit the pack? If an animal is not pulling their weight or interacting healthily, they could be a threat to the survival of the rest of the pack or group, therefore, aggression is necessary to keep them away. This reminds me a bit of the behaviors of baboons in a book I read back in college called, “A Primate’s Memoir.” I think I may re-read that book and give a review at some point. I do remember being very excited by the book, and laughing. The author was rather engaging, yet informative. The best kind of book!
Going back to the paper.
Harlow found that 12 months of isolation essentially obliterated the monkey’s ability to be social.
In terms of learning and his team wrote, “The striking fact, however, is that all the socially isolated monkeys learned effectively after being removed from the social isolation cages. We cannot, at the present time, adequately assess the effect of prolonged total social isolation on the intellectual capabilities of rhesus monkeys…We can, however, state with confidence that the ‘intellectual mind’ is far less crippled than the ‘social mind’ by prolonged total social deprivation if adequate experience is provided subsequently.”
I do have reservations with that, in the sense of the Genie, the feral child, who did not ever catch up in terms of language skills. However, Genie was also abused, and I’m not saying that social isolation is not abuse, but in Genie’s case, there were layers of abuse that involved social isolation, as well as physical and emotional abuse.
Harlow, through his experiments, which involved more than the pit of despair, became somewhat of a celebrity, appearing on TV and traveling around to speak. He was infamous for his terms of the devices he used, like the pit of despair, the rape rack (where female monkeys were forced to mate against their will,) and iron maidens (the term he used for the cloth surrogate mothers he made for baby monkeys).
Briefly, the rape rack was used when Harlow decided to breed the isolate monkeys and produce new offspring from them. When the females refused to mate, he placed them on the rape rack and had them subsequently inseminated. He then found that those isolate monkey mothers killed their infants by chewing off fingers and toes, or even crushing the infants’ head with their teeth. How loving.
The iron maidens were metal “surrogate mothers” who had cloth wrapped around them. Baby monkeys were taken away from their real mothers and given to these iron maidens. Interestingly the baby monkeys would cling on to these iron maidens, only leaving to feed. Apparently, a bad mother is better than no mother.
Harlow went so far as to say he had not feelings for the monkeys. “The only thing I care about is whether a monkey will turn out a property I can publish. I don’t have any love for them. How could you love a monkey?” He also said, “I just have no feeling for them—at all.”
However, he did add, “If my work will save one million human children, I can’t get overly concerned about ten monkeys.”
Harlow was very outspoken. He pushed the idea that mothers are important in the emotional development of their children. The trend in the American psychology of Harlow’s time indicated to mothers to show their children as little affection as possible (?!). Too much affection was considered coddling, and coddling created a weaker child.
With these sorts of thoughts and beliefs running rampant, love, or the lack thereof, had to be tested in a controlled, experimental setting. And that’s what Harlow did.
It seems easy to think of Harlow as cruel for the work he did with his monkeys. But through his work, we began to realize that children need to be affectioned, to be loved. Which all seems common sense now, but did not seem to be in American psychology just decades ago.
Now the ethics.
Clearly, the work was unethical in the sense that it caused undue suffering to sentient organisms. It’s similar to the ticking time bomb scenario: so we have the right to torture a small group pf people if they are able of providing information that could prevent the mass death of others?
However, can Harlow truly be blamed? He experimented in a time when animals were considered to be like dumb, driven cattle, without the complexities of human intelligence and emotions. Harlow’s work demonstrated that monkeys have human emotional attachments and can learn and be intelligent. Harlow even worked to developed now-classic ways to measure learning, like the Wisconsin General Test Apparatus (WGTA), where monkeys are to discover food hidden under toys and objects. Scientists can then learn how the monkeys learn and remember and can discriminate between objects of different colors and shapes. It is also through Harlow’s work that we know how to better take care of the emotional and cognitive needs of humans and other animals.
But then, do the ends justify the means?
Here’s a video, if you’re interested:
This article was originally published on my old blog, Neuravinci.com.