We've updated our Privacy Policy to make it clearer how we use your personal data. We use cookies to provide you with a better experience. You can read our Cookie Policy here.


Three Psychology Experiments That Pushed the Limit of Ethics

Three Psychology Experiments That Pushed the Limit of Ethics content piece image
Test subjects from the Milgram experiments pose beside a "shock box". Credit: Yale University Manuscripts and Archives
Listen with
Register for free to listen to this article
Thank you. Listen to this article using the player above.

Want to listen to this article for FREE?

Complete the form below to unlock access to ALL audio articles.

Read time: 4 minutes

Last month, a team of volunteers emerged from 40 days of isolation in the Lombrives cave in south-west France. This ordeal was part of a scientific study called the Deep Time experiment. The volunteers were tasked with going without sunlight, phones or clocks for the duration of the experiment. The study aimed to understand how the human brain would be affected as it lost its grasp on time and space. Putting human subjects, even volunteers, through this might seem ethically dubious, but pales in comparison to the questions raised by these three studies.

The ultimate isolation: Hebb’s “pathological boredom”

Until COVID-19 lockdown gave everyone an unwanted taster session, extreme isolation was an experience traditionally reserved for long-term prisoners and extremely committed polar scientists. But in 1951, Donald Hebb, a neuroscientist whose discoveries about the brain redefined what we know about learning, undertook a series of tests that would push volunteers into a near-total solitude.

Hebb and his team designed a setup that would isolate test subjects not just from other people, but from virtually all perceptual stimulation. The subjects, for the (relatively generous at the time) sum of $20 a day, were tasked with lying in bed in a small, lit cubicle for 24 hours a day. Breaks were given at mealtimes (eaten sitting on the edge of the bed) and for toilet breaks. The volunteers wore visors that allowed in light but blocked any detailed vision, and touch-restricting cotton gloves. A continuous hum of air conditioning masked any small sounds that might have broken their sensory cocoon.

In 2008, the BBC attempted to re-enact Hebb's experiments. Credit: BBC Horizon

Hebb and his team wanted to see how this environment, one that wasn’t entirely devoid of sensory information, but that was incredibly monotonous and boring, would affect the volunteers. Initially, the participants, who were all university students, thought about their results, or the papers they had due. But after a while, their minds instead drifted onto memories from their childhood. Eventually, most of the participants reported that they became unable to think about anything for any length of time. These details were reported by Hebb’s collaborator Woodburn Heron in an article published in Scientific American. The subjects also showed impaired mental performance, registering lower results on tests of mental arithmetic and word association.

Most strikingly of all, the subjects reported that, despite their complete absence of sensory stimulation, they experienced an array of hallucinations, including one participant who saw endless images of babies. These hallucinations, which Heron compared to the effects of the hallucinogenic drug mescaline, grew in complexity over time – one participant eventually reported “a procession of squirrels with sacks over their shoulders marching ‘purposefully’across the visual field.”

The hallucinations were accompanied by sounds and even sensations across the volunteers’ bodies. Summing up these weird and distressing effects, Heron concluded that “a changing sensory environment seems essential for human beings.”

How malleable is our willpower?

Perhaps the most infamous psychology trial, the Milgram experiments were conducted by Yale University’s Stanley Milgram in 1961. The experimental setup involved an experimenter, a volunteer dubbed the “teacher” and an actor, who pretended to be another volunteer –the “learner”.

The teacher was told that they were participating in a test of learning and memory that would investigate how well punishment encouraged ability. They were placed in front of a series of buttons representing different levels of electric shock that they were told would be delivered to their fellow “volunteer”, who was strapped into what appeared to be an electric chair in an adjacent room. The teacher was told that they were to conduct a word test with the restrained learner and were to shock them if they made any mistakes. The buttons, which included warning labels for the intensity of the “shock” they gave, were meant to deliver up to a dangerous 450 volts of stimulation.

The buttons, of course, did nothing, but the actor was trained to respond with increasingly agonized reactions to their “shocks”. The teacher, encouraged by the lab coat-wearing experimenter was, in reality, being tested for their level of obedience – an experiment that aimed to understand whether individuals who have carried out horrendous crimes, such as Holocaust architect Adolf Eichmann, could really have just been “following orders”.

The teacher could not see the learner, but as the “shocks” increased, pre-recorded shrieks of agony were played over a loudspeaker, and the learner eventually started banging on the separating wall in protests. At the highest voltages, the “shocked” learner fell silent.

Milgram’s findings were remarkable. The teachers moved through the voltages at the behest of the experimenter, who gave increasingly strident instruction – eventually telling them, “You have no other choice; you must go on.”

The experiment only ended if the teacher refused this highest level of instruction, or if they delivered the highest voltage three times in a row. To the research team’s amazement, 26 of 40 participants proceeded to the highest voltage. Whilst the participants often reacted with horror to their instruction, with some breaking out in laughing fits and even seizures, all administered at least 300 volts to their learners. Milgram reflected on these controversial experiments years later in his book Obedience to Authority: An Experimental View, where he summarized that his trials showed “the capacity for man to abandon his humanity, indeed, the inevitability that he does so, as he merges his unique personality into larger institutional structures.” More recent analysis has thrown Milgram's subjectivity into doubt, as summarized by psychologist Gina Perry

The Facebook study: How contagious are emotions?

A much more recent, but equally controversial study, looked at the how human emotions could become “contagious” to others with relative ease. This study didn’t rope in unwitting university students, but instead involuntarily recruited nearly 700,000 Facebook users.

The study, which was published in the Proceedings of the National Academy of Sciences, had a simple aim. The authors, members of Facebook’s Core Data Science Team, wanted to test whether seeing positive emotions online would make users happy, or whether it would make them sad as a kind of spiteful reaction, as had been previously theorized. The team were given the power to alter the emotional content of their subjects’ Facebook feeds over a week in 2012. They found that when feeds were biased in favor of negative emotions, users started posting more negative content themselves. When happier emotions were shown, the opposite happened. No fake content was used, but rather the team simply changed the feed’s algorithm so that certain types of content were filtered out.

Credit: Pixabay

This study started huge controversy when it was ascertained that the only consent Facebook sought was signing up for the platform. Facebook's Data Use Policy, the company said, gave them all the permission they needed to play around with users’ feeds. Whilst these findings were interesting, the ethically dubious way in which the study was conducted makes for uncomfortable reading. The ethical quandaries involved, and the reasons why the study was able to bypass certain regulations, were summed up by bioethicist Michelle N. Meyer in an article for WIRED