The Carney Landis Experiment

Suppose you’re making your way through a jungle, and in pulling aside a bush you find yourself before a huge snake, ready to attack you. All of a sudden adrenaline rushes through your body, your eyes open wide, and you instantly begin to sweat as your heartbeat skyrockets: in a word, you feel afraid.
But is your fear triggering all these physical reactions, or is it the other way around?
To make a less disquieting example, let’s say you fall in love at first sight with someone. Are the endorphines to be accounted for your excitation, or is your excitation causing their discharge through your body?
What comes first, physiological change or emotion? Which is the cause and which is the effect?

This dilemma was a main concern in the first studies on emotion (and it still is, in the field of affective neurosciences). Among the first and most influential hypothesis was the James-Lange theory, which maintained the primacy of physiological changes over feelings: the brain detects a modification in the stimuli coming from the nervous system, and it “interprets” them by giving birth to an emotion.

One of the problems with this theory was the impossibility of obtaining clear evidence. The skeptics argued that if every emotion arises mechanically within the body, then there should be a gland or an organ which, when conveniently stimulated, will invariably trigger the same emotion in every person. Today we know a little bit more of how emotions work, in regard to the amygdala and the different areas of cerebral cortex, but at the beginning of the Twentieth Century the objection against the James-Lange theory was basically this — “come on, find me the muscle of sadness!

In 1924, Carney Landis, a Minnesota University graduate student, set out to understand experimentally whether these physiological changes are the same for everybody. He focused on those modifications that are the most evident and easy to study: the movement of facial muscles when emotion arises. His study was meant to find repetitive patterns in facial expressions.

To understand if all subjects reacted in the same way to emotions, Landis recruited a good number of his fellow graduate students, and began by painting their faces with standard marks, in order to highlight their grimaces and the related movement of facial muscles.
The experiment consisted in subjecting them to different stimuli, while taking pictures of their faces.

At first volunteers were asked to complete some rather harmless tasks: they had to listen to jazz music, smell ammonia, read a passage from the Bible, tell a lie. But the results were quite discouraging, so Landis decided it was time to raise the stakes.

He began to show his subjects pornographic images. Then some medical photos of people with horrendous skin conditions. Then he tried firing a gunshot to capture on film the exact moment of their fright. Still, Landis was having a hard time getting the expressions he wanted, and in all probability he began to feel frustrated. And here his experiment took a dark turn.

He invited his subjects to stick their hand in a bucket, without looking. The bucket was full of live frogs. Click, went his camera.
Landis encouraged them to search around the bottom of the mysterious bucket. Overcoming their revulsion, the unfortunate volunteers had to rummage through the slimy frogs until they found the real surprise: electrical wires, ready to deliver a good shock. Click. Click.
But the worst was yet to come.

The experiment reached its climax when Landis put a live mouse in the subject’s left hand, and a knife in the other. He flatly ordered to decapitate the mouse.
Most of his incredulous and stunned subjects asked Landis if he was joking. He wasn’t, they actually had to cut off the little animal’s head, or he himself would do it in front of their eyes.
At this point, as Landis had hoped, the reactions really became obvious — but unfortunately they also turned out to be more complex than he expected. Confronted with this high-stress situation, some persons started crying, others hysterically laughed; some completely froze, others burst out into swearing.

Two thirds of the paricipants ended up complying with the researcher’s order, and carried out the macabre execution. In any case, the remaining third had to witness the beheading, performed by Landis himself.
As we said, the subjects were mainly other students, but one notable exception was a 13 years-old boy who happened to be at the department as a patient, on the account of psychological issues and high blood pressure. His reaction was documented by Landis’ ruthless snapshots.

Perhaps the most embarassing aspect of the whole story was that the final results for this cruel test — which no ethical board would today authorize — were not even particularly noteworthy.
Landis, in his Studies of Emotional Reactions, II., General Behavior and Facial Expression (published on the Journal of Comparative Psychology, 4 [5], 447-509) came to these conclusions:

1) there is no typical facial expression accompanying any emotion aroused in the experiment;
2) emotions are not characterized by a typical expression or recurring pattern of muscular behavior;
3) smiling was the most common reaction, even during unpleasant experiences;
4) asymmetrical bodily reactions almost never occurred;
5) men were more expressive than women.

Hardly anything that could justify a mouse massacre, and the trauma inflicted upon the paritcipants.

After obtaining his degree, Carney Landis devoted himself to sexual psychopatology. He went on to have a brillant carreer at the New York State Psychiatric Institute. And he never harmed a rodent again, despite the fact that he is now mostly remembered for this ill-considered juvenile experiment rather than for his subsequent fourty years of honorable research.

There is, however, one last detail worth mentioning.
Alex Boese in his Elephants On Acid, underlines how the most interesting figure of all this bizarre experiment went unnoticed: the fact that two thirds of the subjects, although protesting and suffering, obeyed the terrible order.
And this percentage is in fact similar to the one recorded during the infamous Milgram experiment, in which a scientist commanded the subjects to inflict an electric shock to a third individual (in reality, an actor who pretended to receive the painful discharge). In that case as well, despite the ethical conflict, the simple fact that the order came from an authority figure was enough to push the subjects into carrying out an action they perceived as aberrant.

The Milgram experiment took place in 1961, almost forty years after the Landis experiment. “It is often this way with experiments — says Boese — A scientis sets out to prove one thing, but stumbles upon something completely different, something far more intriguing. For this reason, good researchers know they should always pay close attention to strange events that occur during their experiments. A great discovery might be lurking right beneath their eyes – or beneath te blade of their knife.

On facial expressions related to emotions, see also my former post on Guillaume Duchenne (sorry, Italian language only).

La biblioteca delle meraviglie IV

Paolo Albani e Paolo Della Bella


(1999, Zanichelli)

Raymond Queneau (l’autore di Esercizi di stile, I fiori blu e Zazie nel metrò, per intenderci) aveva in progetto di compilare una “Enciclopedia delle scienze inesatte”; la ricerca avrebbe dovuto essere inclusa nei suoi studi sui fous littéraires, cioè quegli autori che non seguono strade battute e “integrate” nella società in cui vivono. Partendo da questa idea, Albani e Della Bella realizzano quello che è a tutt’oggi il più completo e indispensabile compendio enciclopedico sulle scienze anomale. Indispensabile, perché ci permette di curiosare in una galassia semisepolta di teorie bislacche, folli o magari plausibili ma dimenticate; e poi perché approcciarsi a queste scienze “non ortodosse”, se da un lato diverte, e molto, dall’altro spinge a riflettere. Ogni voce dell’enciclopedia è contrassegnata da un simbolo che rimanda a diversi ambiti o categorie, in modo da comprendere subito di cosa stiamo parlando. Le dieci categorie sono le seguenti:

1. Scienze e teorie elaborate da eterodossi scientifici e mattoidi scienziati;
2. Scienze e teorie inventate da letterati e artisti;
3. Scienze e teorie comiche, effimere, parodie di scienze;
4. Scienze della fantascienza e utopiche;
5. Scienze e teorie non riconosciute, marginalizzate, alternative alla scienza ufficiale;
6. Scienze e teorie dimenticate, scomparse, abortite;
7. Scienze potenziali, al confine di altre scienze;
8. Scienze e teorie bizzarre, avanzate da studiosi accademicamente riconosciuti;
9. Scienze occulte, paranormali, magiche, religiose;
10. Studi su pseudoscienze, su mattoidi scienziati ed eterodossi scientifici.

Dalle teorie sulla Terra cava, alla “bestemmiologia”, dalle più disparate cosmogonie alternative fino alla teologia genetica,ogni pagina dell’enciclopedia è un’incessante sorpresa che dimostra come nella storia della scienza ci sia sempre stato qualcuno che cercava di immaginare le cose da una nuova prospettiva. Sarebbe facile, e rassicurante, ridurre molte di queste teorie ad infantilismi o errori concettuali. Siamo abituati a dire: “ieri pensavamo che…, mentre oggi sappiamo che…”, come se la verità fosse stata raggiunta senza ombre di dubbio. Eppure qualsiasi conquista è provvisoria, e ogni sapere viene invariabilmente ampliato, ridefinito, corretto, in un costante affinamento. E tutto questo è possibile perché una moltitudine di uomini, alcuni scienziati, altri artisti, altri pazzoidi strampalati, continuano a porsi domande ed elaborare risposte. Che molte di queste teorie siano bislacche e assurde non fa che testimoniare il fascino dell’infinita ricerca: l’uomo che esce dipinto da queste pagine è, per fortuna, sempre pronto a dimenticare le “verità assodate”, e immaginare possibilità e punti di vista inediti e diversi.

Piero Bocchiaro


(2009, Laterza)

Perché si fa il male? Chiunque, posto in una determinata condizione, sarebbe in grado di farlo? Il piccolo, apparentemente innocuo libriccino di Piero Bocchiaro racchiude in realtà uno specchio nel quale non vorremmo (ma dovremmo) fissare lo sguardo. Prendendo spunto da quattro dei più famosi e controversi esperimenti di psicologia sociale (l’esperimento di Milgram, quello di Darley e Latané, l’arcinoto esperimento carcerario di Stanford e un ulteriore esperimento di Zimbardo), Bocchiaro estende i risultati della ricerca “in laboratorio” ad alcuni fatti di cronaca, per analizzarli alla luce dei dati sperimentali. Si affrontano quindi il caso del gerarca nazista Eichmann; il delitto Genovese, giovane italo-americana assassinata dinanzi allo sguardo passivo di 38 testimoni; la tragedia dell’Heysel, stadio belga scenario di un sanguinoso scontro fra tifoserie; e le torture di Abu Ghraib, carcere tristemente noto per gli atti disumani perpetrati da alcuni militari americani sui detenuti iracheni. Con linguaggio chiaro e comprensibile anche ai non addetti ai lavori, l’autore ci accompagna attraverso decenni di ricerche psicologiche che indagano le motivazioni della violenza e del mancato soccorso.

Sapevate che se venite aggrediti in un posto affollato avete paradossalmente meno possibilità di essere soccorsi che se l’aggressione accade in un vicolo semideserto? Siete davvero sicuri che rifiutereste l’ordine di un superiore che vi intima di usare violenza su un vostro collega? Quando vedete in televisione episodi di sciacallaggio, giudicate quelle persone dei “vandali” e siete intimamente convinti che voi, una cosa del genere, non la fareste proprio mai? Purtroppo, le ricerche in ambito della psicologia sociale dimostrano che tutti, chi più chi meno, posti nella “giusta” situazione straordinaria, sono capaci e pronti a fare ciò che, in momenti più normali, definirebbero “azioni malvagie”. Scopriamo così che molte delle nostre certezze sono piuttosto fragili: la nostra auto-immagine di persone buone e generose, pronte ad intervenire per aiutare il prossimo, e di certo lontane da pulsioni di violenza, viene a poco a poco messa in discussione. Eppure, nel momento in cui ci rendiamo conto dei meccanismi psicologici che scattano in situazioni di emergenza, ne usciamo rafforzati; e chissà che, grazie a questo piccolo libro, non finiremo magari per riconoscere il “tranello mentale” in cui stiamo cadendo, e riuscire ad agire nel modo in cui davvero desideriamo agire.