martedì 24 gennaio 2017

Economia della superstizione

Dietro molti atti che riteniamo sommamente irrazionali spesso si nasconde una logica e una spiegazione ragionevole.
Peter Leeson è forse lo studioso che più si è impegnato a dimostrare la singolare tesi. Nel saggio “Oracles” si cimenta per l’appunto con la pratica degli oracoli.
La sua tesi:
… My theory explains oracles as institutional solutions to “lowgrade” interpersonal conflicts— petty grievances and frustrations resulting from perceptions or feelings of personal offense— that government is unable to resolve…
La teoria verrà verificata sul campo:
… I consider a society of persons who rely exclusively on oracles to decide how to behave in situations of low-grade conflict: the Azande of Africa…
L’economia della superstizione si è già occupata in passato della funzione oracolare
… Iannaccone et al. (2011) consider how political rulers in ancient Greek city states used Delphi as a “neutral nexus”— a location and venue of political independence that helped rulers improve cooperation across their political economies… Delphic Oracle as a means of assisting political rulers to commit to arbitrary actions that preserved status quo relationships between them…
La randomizzazione esplicita delle scelte libera dal carico cognitivo e da rimpianti o risentimenti.
Ma Peter Leeson intende andare oltre Iannaccone:
… my analysis can be seen as building on an observation that Myerson (2009) makes in his appreciation of Thomas Schelling’s (1960) work. Though his paper isn’t about oracles, here Myerson notes the role that oracles could play in providing focal points for social coordination…
Ma cosa deve intendersi per “equilibrio correlato”?
… Before choosing their strategies, players observe a public signal. This signal randomly assigns, or “recommends,” a strategy to each player. If no player wants to deviate from his signal-assigned strategy, supposing the others won’t deviate from theirs, the strategies chosen constitute a correlated equilibrium. We call this equilibrium “correlated” because the strategies that compose it aren’t chosen independently…
Facciamo un esempio:
… To see how oracles can create correlated equilibrium, suppose that before i and j decide how to cope with their conflict they consult a Magic 8 Ball. To use this oracle i and j ask it the following question: “Tell us, oh Magic 8 Ball, great one and infallible teller of eternal truths, is i’s (or j’s) animus toward j (or i) justified?” The die inside the 8 Ball has three sides. One of them reads “Yes. It is certainly true.” Another side reads: “No. It is certainly untrue.” The third side reads: “Ask again later.” The neighbors put their hands on the oracle and shake it together. They then turn it upside down to see what the oracle has divined. The neighbors believe the 8 Ball is infallible. They repose complete faith in its ability to get to the bottom of their conflict— i.e., to accurately identify which neighbor is in the wrong— and agree to condition their behavior toward the other on whatever it answers. If the 8 Ball answers “yes,” the neighbors agree that i’s animus is justified… both neighbors following their oracle-assigned strategies is a correlated equilibrium…
A volte, certi piccoli ma fastidiosi conflitti persistono perché non ci si parla apertamente, magari stando di fronte ad un terzo verso cui tutti nutrono fiducia: l’oracolo è un modo per farlo ed eventualmente dissiparli.  Chiarirsi è importante. Studiando le istituzioni degli Azande notiamo che si puo’ procedere anche oltre su questa via pacificatoria: basta non abbinare le responsabilità ad una colpa.
Chi sono gli Azande? E quali conflitti affidano all’oracolo?:
… The Azande is a tribe of one to four million persons who inhabit parts of the Democratic Republic of Congo, southern Sudan, and southeastern Central African Republic. The persons in this society put the theory of oracles developed above to good use… Between 1926 and 1930, anthropologist E.E. Evans-Pritchard lived among and closely studied the Zande people of Anglo-Egyptian Sudan. The British colonized these people in 1905. My discussion of Zande society, beliefs, and oracular usage is based on Evans-Pritchard’s (1937) detailed and lengthy account… Low-grade conflicts— the petty, passive, everyday sort that exist between neighbors arising out of feelings of jealously, envy, rivalry, and meanness— fell outside the formally governed arena… In the daily tasks of life there is ample scope for friction. . . . Among his neighbours a man is sure to have both secret and open enemies. There may have been quarrels about cultivations and hunting areas. There may have been suspicions about designs on a wife. There may have been rivalry at dances. One may have uttered unguarded words which have been repeated by another. A man may have thought that a song referred to himself . . . . All unkind words and malicious actions and innuendoes are stored in the memory for retaliation…
Gli Azande sono particolarmente permalosi e taluni micro-conflitti potrebbero degenerare se non fossero risolti dall’oracolo:
… Azande who, according to Evans-Pritchard, are “extremely, almost morbidly, sensitive, touched to the quick by any unkindness, insult, humiliation or hostility” (EvansPritchard, 1929: 199). Indeed, “in all [Zande] economic and social pursuits there is opportunity for offence to be given and offence to be taken where none is meant…
Ma come si articola la procedura dell’oracolo?:
… At the core of that system is a belief in witchcraft called mangu. According to Zande belief, witch-hood is a physiological condition. In the intestine of some people lies a substance that enables them to send out witchcraft against their enemies… Since most, if not virtually all, commoner Zande families have witches in them, and many of them are unaware of this fact, persons accused of witchcraft are neither maligned nor even looked on with askance for being witches per se… Through benge (l’oracolo) an oracle consulter doesn’t seek to determine the culprits of such conflicts directly, however. He seeks to identify the witch behind his recent misfortune…
La credenza del demone è decisiva: il “colpevole” è quasi sempre portatore inconsapevole del demone che causa disgrazia a terzi, cosicché non esistono colpe soggettive vere e proprie.
La superstizione oracolare è una soluzione efficiente dei conflitti in regime di anarchia:
… “Only in those areas of society which were left unstructured by the political system did men accuse each other of witchcraft” (Douglas, 1966: 128). Witchcraft suspicions and accusations are the means by which the Azande express low-grade conflicts with their neighbors that can’t be addressed through government….
Poniamo che si ammali un membro della famiglia:
… he or one of his family members becomes ill. This is when he becomes concerned with witches, who are undoubtedly responsible for his difficulty. And it’s at these times that he seeks to identify the offending witch so that he can command him to cease his injuries, which the unwitting witch will ordinarily do… To identify the witch offending him in such cases, a Zande consults an oracle called benge. Benge works as follows. Poison harvested from a special vine is fed to a fowl. The oracle consulter (or someone on his behalf) treats benge to “a speech of five or ten minutes” in which he “puts before the oracle every detail of the situation… The consulter then asks the oracle a yes-or-no question about whether some neighbor is bewitching him in whatever manner befits his recent misfortune. He shakes the fowl to ensure that it has swallowed the poison… As he shakes the fowl, the consulter addresses the oracle in the following way: “If [a neighbor’s name] is guilty of bewitching my [hunt, person, etc.], poison oracle kill the fowl. If [neighbor’s name] is innocent, poison oracle spare the fowl… The Azande consult their oracles with the assistance, or at least observance, of one or several trusted persons
Il nome della persona su cui l’oracolo deve sentenziare, evidentemente, non è arbitrario ma un concreto sospetto a cui la vittima è legata in qualche modo:
… The name( s) a Zande oracle consulter puts before benge as a potential person bewitching him is not arbitrary. The reason for this is that the person( s) who he believes may be bewitching him is not arbitrary. “[ O] ne does not places names of people before the oracle in a haphazard manner. One selects only the names of those with whom one is on bad terms… According to Zande belief, witchcraft is motivated by personal animus. “A witch attacks a man when motivated by hatred, envy, jealousy, and greed… “It is thus clear that allegations of witchcraft reflect the nature of social relationships
Se l’oracolo scagiona il sospetto chi lo ha interrogato si rilassa e abbandona i suoi sospetti ripristinando la pace sociale.
Se invece la sentenza è di colpevolezza, l’imputato ha modo di scusarsi con formule rituali che ripristinano la pace sociale. Ricordo solo che la colpevolezza non è mai soggettiva, cosicché il “colpevole” non troverà mai qualcosa che non va nella sentenza oracolare prestandosi alle scuse rituali e, anzi, nutrendo un senso di gratitudine per l’opportunità che gli viene fornita di scusarsi:
… If the poison oracle “convicts”… “When he is informed that the oracles have declared that he has bewitched a certain man he says that he is very sorry and is totally ignorant of having done so, blows some water from his mouth in a sign of goodwill,” recalling or “cooling” his unwitting witchcraft against the consulter, “and the matter is closed”… “demonstration of remorse” following the oracle’s declaration, “set these ill feelings to rights”…
Per mantenere la sua credibilità l’esito dell’ oracolo deve essere random. E in effetti l’oracolo Azande ha procedure che garantiscono esito 50/50:
… If benge always vindicated the consulter’s animus or always vindicated his neighbor’s, one of the parties would be unwilling to abide by the poison oracle’s declarations… When a Zande consults benge regarding a particular person, he does so not once, but twice. The first oracular consultation is called bambata sima. The second is called gingo. “To obtain a conclusive answer the result of the first test has to be confirmed by feeding the poison to a second fowl…  For example, if in bambata sima the oracle consulter inquires of the oracle in the following manner: “If [a neighbor’s name] is guilty of bewitching my [hunt, person, etc.], poison oracle kill the fowl. If [neighbor’s name] is innocent, poison oracle spare the fowl,” in gingo he must inquire of the oracle this way: “If [a neighbor’s name] is guilty of bewitching my [hunt, person, etc.], poison oracle spare the fowl… Benge results support the argument that it tends to produce opposing results with 50 percent probability…
La sentenza oracolare non deve prestarsi ad ambiguità proprio perché è chiamata a dissipare ogni ambiguità. In questo senso bisogna limitare liti a consultazione simultanea:
… The oracle declares one party’s animus justified in every case in which it declares the other party’s animus unjustified, and vice versa. This result is secured by the nature of the question an oracle consulter necessarily uses when inquiring of the oracle… The oracle consulter must ask benge a yes-or-no question… the consulter is justified in demanding an apology and recall of witchcraft from his neighbor, and his neighbor must apologize to the consulter and recall his witchcraft… when one neighbor apologizes to the other explicitly, the benge ritual requires the apologizer to display genuineness in asking for forgiveness. This helps ensure that through benge the conflict is indeed quashed… the phrases in which he is expected to express his regret are more or less stereotyped, and even the earnest and apologetic tone of voice in which he utters them is determined by tradition… two neighbors in low-grade conflict could in principle simultaneously consult their oracles and each of their oracles could in principle vindicate their animus toward their neighbor by declaring that the other is bewitching him…
Il perno dell’istituzione resta comunque la fede nell’infallibilità dell’oracolo:
… Fortunately for the Azande, faith in the fairness and infallibility of benge is universal and nearly perfect… As a consequence of this trust, “the judgments of benge are always accepted as final”… “the normal reaction to the presentation of a hen’s wing” is “one of acquiescence in which assurances of goodwill take the place of any denial”… when the oracle says that he is killing a man by his witchcraft he is probably thankful for having been warned”… Neither party would contemplate behaving in a manner other than that directed by benge. And since benge always coordinates parties’ behaviors, conflict is resolved efficiently….
Quando siamo vittime di una disgrazia l’ impulso naturale è quello di “agire” purchessia nella speranza di compensare le perdite sofferte. Un giocatore perdente raddoppia le puntate per riportarsi alla pari, per esempio.  Questo impulso irrazionale opera oggi come operava ieri, e forse oggi causa ancora più danni di ieri: dopo un terremoto, per esempio, i politici fanno a gara nel proporre forme di prevenzione costosissima quanto inutile, tanto chi bada alle spese in certe circostanze? Per porre un freno a queste reazioni inconsulte  l’uomo ha istituzionalizzato alcune pratiche (penso alla preghiera) per potersi ritagliare un momento di riflessione dopo essere stato “colpito” dalla sorte. In molti popoli l’oracolo svolge o ha svolto funzioni simili: consentire all’uomo vittima di una disgrazia (malattia, morte, carestia…) di agire in modo rituale potendo sfogare i suoi impulsi senza fare troppi danni alla comunità d’appartenenza.