The experiment that removes all certainty

frafiomatale (77)in #science • 12 hours ago

❗This is the English version of the post L'esperimento che toglie ogni certezza, originally published in Italian in the ITALY community.

In 200 BC, the famous Roman playwright Titus Maccius Plautus wrote and staged Menaechmi, a work that achieved great success among audiences of the time. The plot revolved around a misunderstanding, namely the exchange of identities between two twin brothers, capable of generating numerous comic situations typical of the comedy of errors.

One of the most successful scenes is the one in which a character is called upon to simulate a kind of mental illness. As it unfolds, the doctor treating him fails to notice the deception and mistakenly attributes every behavior of the patient, even the most ordinary ones, to the symptoms of a psychiatric disorder, in the most classic confirmation bias.

More than two thousand years later, in 1973, the American psychologist David Rosenhan, following in the footsteps of Plautus, conducted a rather disturbing experiment inside several American psychiatric hospitals. Eight volunteers were recruited, three women and five men, tasked with simulating a specific psychiatric disorder and studying the actual ability of doctors to unmask an impostor and assess the real degree of mental health of the patients.

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The volunteer subjects, free of previous psychiatric conditions, had themselves admitted by claiming to hear voices coming from inside their heads. All of them told doctors at the various hospitals involved (chosen for differing reputations and sizes) the same story, even using the very same words.

After a few days of hospitalization, the pseudopatients claimed to have resolved their problem and to no longer hear any voices, but according to the professionals treating them, things were quite different. Every behavior, from taking notes to spending hours walking the corridors out of boredom, was interpreted, just as Plautus had “foretold,” as a precise psychological symptom.

Seven of them were diagnosed with schizophrenia, while the last was even diagnosed with manic-depressive psychosis. The funny thing was that one third of the real patients in the hospitals involved, after interacting with the experiment’s volunteers, realized the charade and openly pointed them out as journalists or private investigators.

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Although the volunteers declared themselves cured and requested discharge, things turned out to be anything but easy: not only was no one recognized as an impostor, but they were forced to take psychotropic drugs (which they flushed down the toilet) and to declare themselves ill, remaining hospitalized for a minimum of 7 up to a maximum of 52 days before being discharged.

Once published in the prestigious journal Science, the results of the experiment caused quite a stir. A well-known hospital, not involved in the original experiment, criticized Rosenhan’s methods, subtly accusing him of falsifying the data.

According to their view, it was virtually impossible to deceive specialized doctors like those in their institution, so much so that they decided to raise the stakes and agree to a peculiar challenge: over the following three months, the psychologist would send one or more impostors to the hospital, challenging the staff to recognize and unmask them.

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During the challenge period, the hospital received 193 patients, labeling 41 cases as “impostors” and 42 as suspects. However, Rosenhan bluffe magnificently, in fact sending no one at all.

The human mind remains a largely undeciphered and unexplored universe, impossible in many cases to label even by seasoned professionals. Rosenhan demonstrated this over 50 years ago, and it is worth remembering every day, when we feel tempted to categorize thoughts, behaviors, or expressions—our own and those of others.