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mercoledì 26 ottobre 2016

HL Are Disagreements Honest? Tyler Cowen Robin Hanson

Are Disagreements Honest?
Tyler Cowen Robin Hanson
Citation (APA): Hanson, T. C. R. (2014). Are Disagreements Honest? [Kindle Android version]. Retrieved from Amazon.com

Parte introduttiva
Evidenzia (giallo) - Posizione 1
Are Disagreements Honest? Tyler Cowen Robin Hanson*
Evidenzia (giallo) - Posizione 18
I. Introduction
Evidenzia (giallo) - Posizione 18
People disagree all of the time,
Evidenzia (giallo) - Posizione 18
politics, morality, religion, and relative abilities.
Evidenzia (giallo) - Posizione 19
intelligent people
Evidenzia (giallo) - Posizione 19
Disagreements usually persist,
Evidenzia (giallo) - Posizione 20
Nor is disagreement usually embarrassing;
Evidenzia (giallo) - Posizione 22
about what is objectively true,
Evidenzia (giallo) - Posizione 22
people often consider their disagreements to be honest,
Evidenzia (giallo) - Posizione 25
Yet according to well-known theory, such honest disagreement is impossible. Robert Aumann (1976) first developed general results about the irrationality of “agreeing to disagree.” He showed that if two or more Bayesians would believe the same thing given the same information (i.e., have “common priors”), and if they are mutually aware of each other's opinions (i.e., have “common knowledge”), then those individuals cannot knowingly disagree. Merely knowing someone else’s opinion provides a powerful summary of everything that person knows, powerful enough to eliminate any differences of opinion due to differing information.
Nota - Posizione 29
NN PUÒ ESISTERE UN DISACCORDO ONESTO
Evidenzia (giallo) - Posizione 29
Aumann’s impossibility result
Evidenzia (giallo) - Posizione 37
It can cover the age of a car, the correctness of quantum mechanics, whether God created the universe, and which political candidate is more likely to induce prosperity. It can even apply to morality,
Nota - Posizione 38
DOMINIO DELLA TEORIA
Evidenzia (giallo) - Posizione 40
assumption of common priors,
Evidenzia (giallo) - Posizione 40
same information
Evidenzia (giallo) - Posizione 40
same beliefs.
Evidenzia (giallo) - Posizione 41
extreme position that that priors must be common
Evidenzia (giallo) - Posizione 41
opposite extreme position, that any possible prior is rational.
Evidenzia (giallo) - Posizione 43
Are typical human disagreements rational?
Evidenzia (giallo) - Posizione 45
are typical human disagreements honest?
Evidenzia (giallo) - Posizione 45
To consider this question, we do not need to know what sorts of differing priors are actually rational, but only what sorts of differences people seem to think are rational. If people mostly disagree because they systematically violate the rationality standards that
Nota - Posizione 46
ELUDERE UN PROBLEMA INSOLUBILE
Evidenzia (giallo) - Posizione 52
they profess, and hold up for others, then we will say that their disagreements are dishonest.
Nota - Posizione 52
c
Evidenzia (giallo) - Posizione 55
We will tentatively conclude
Evidenzia (giallo) - Posizione 55
self-favoring
Evidenzia (giallo) - Posizione 56
self-deception
Evidenzia (giallo) - Posizione 57
II. The Phenomena of Disagreement
Nota - Posizione 58
T
Evidenzia (giallo) - Posizione 61
both sides typically believe themselves to be truth-seekers,
Evidenzia (giallo) - Posizione 63
Disagreements do not typically embarrass us.
Evidenzia (giallo) - Posizione 67
high-IQ individuals seem no less likely to disagree
Evidenzia (giallo) - Posizione 68
“the courage of their convictions.”
Evidenzia (giallo) - Posizione 72
Psychologists suggest
Evidenzia (giallo) - Posizione 72
believing that he or she is better than others
Evidenzia (giallo) - Posizione 73
even though people in fact tend to be more influenced than they realize (Wilson, Gilbert, & Wheatley 1998).
Evidenzia (giallo) - Posizione 76
People are usually more eager to speak than they are to listen, the opposite of what a simple information-collection model of discussion would predict
Evidenzia (giallo) - Posizione 78
inclined to believe what they "want to believe."
Evidenzia (giallo) - Posizione 78
For example, most people, especially men, estimate themselves to be more able than others
Nota - Posizione 79
x
Evidenzia (giallo) - Posizione 80
Gilovich (1991, p.77) cites a survey of university professors, which found that 94% thought they were better at their jobs than their average colleagues. A survey of sociologists found that almost half said they expected to become among the top ten 3 On the tendency for polarization, see Sunstein (1999).
Nota - Posizione 81
x
Evidenzia (giallo) - Posizione 83
People also tend to think more highly of their groups,
Evidenzia (giallo) - Posizione 85
III. The Basic Theory of Agreeing to Disagree
Nota - Posizione 85
T
Evidenzia (giallo) - Posizione 86
used Bayesian decision theory.
Evidenzia (giallo) - Posizione 89
simple parable.
Evidenzia (giallo) - Posizione 89
Imagine that John hears a noise, looks out his window and sees a car speeding away. Mary also hears the same noise, looks out a nearby window, and sees the same car. If there was a shooting, or a hit-and-run accident, it might be important to identify the car as accurately as possible. John and Mary’s immediate impressions about the car will differ, due both to differences in what they saw and how they interpreted their sense impressions. John’s first impression is that the car was an old tan Ford, and he tells Mary this. Mary’s first impression is that the car was a newer brown Chevy, but she updates her beliefs upon hearing from John. Upon hearing Mary’s opinion, John also updates his beliefs. They then continue back and forth, trading their opinions about the likelihood of various possible car features. (Note that they may also, but need not, trade evidence in support of those opinions.) If Mary sees John as an honest truth-seeker who would believe the same things as Mary given the same information
Evidenzia (giallo) - Posizione 98
then Mary should treat John’s differing opinion as indicating things that he knows but she does not. Mary should realize that they are both capable of mistaken first impressions. If her goal is to predict the truth, she has no good reason to give her own observation greater weight, simply because it was hers. Of course, if Mary has 20/20 eyesight, while John is nearsighted, then Mary might reasonably give more weight to her own observation. But then John should give her observation greater weight as well. If they can agree on the relative weight to give their two observations, they can agree on their estimates regarding the car. Of course John and Mary might be unsure who has the better eyesight.
Evidenzia (giallo) - Posizione 105
opinions should eventually stop changing, at which point they should become mutually aware (i.e., have “common knowledge”) of their opinions
Evidenzia (giallo) - Posizione 107
They will each know their opinions, know that they know those opinions, and so on.
Nota - Posizione 107
CONOSCENZA PROFONDA
Evidenzia (giallo) - Posizione 108
disagree is problematic, given such mutual awareness.
Segnalibro - Posizione 108
Evidenzia (giallo) - Posizione 122
they would each have exactly the same information, and thus should each have the same estimate of the age of the car.
Nota - Posizione 122
TRA I MONDI POSSIBILI CON COPPIA XY SCEGLIRANNO QUELLO CON .... AVRANN CONDIVISO TANTO DA ASSIMILARE GLI APRIORI
Evidenzia (giallo) - Posizione 128
discussion path of their alternating expressed opinions must follow a random walk.
Evidenzia (giallo) - Posizione 130
"Dutch book" arguments
Evidenzia (giallo) - Posizione 130
These arguments showed that if an agent is willing to take bets on either side of any proposition, then to avoid guaranteed losses, his betting odds must satisfy the standard probability axioms.
Nota - Posizione 131
DUTCH
Evidenzia (giallo) - Posizione 134
in ordinary practice,
Evidenzia (giallo) - Posizione 134
we know that disagreement is persistent.
Evidenzia (giallo) - Posizione 138
IV. Generalizations of the Basic Theory
Nota - Posizione 138
T
Evidenzia (giallo) - Posizione 139
when these assumptions are considerably relaxed.
Evidenzia (giallo) - Posizione 143
We also can relax the requirement that John and Mary be absolutely sure of the things they are mutually aware
Evidenzia (giallo) - Posizione 144
they have “common knowledge.”
Evidenzia (giallo) - Posizione 145
assume only “common belief.”
Evidenzia (giallo) - Posizione 149
Thus John and Mary need not be absolutely sure that they are both honest, that they heard each other correctly, or that they interpret language the same way.
Nota - Posizione 150
x
Evidenzia (giallo) - Posizione 164
beliefs
Evidenzia (giallo) - Posizione 164
information
Evidenzia (giallo) - Posizione 165
mental context,
Evidenzia (giallo) - Posizione 165
their style of analysis,
Evidenzia (giallo) - Posizione 165
recent thoughts.
Evidenzia (giallo) - Posizione 168
John should pay attention to Mary's opinion not only because it may embody information that John does not have, but also because it is the product of a different mental context, and John should want to average over as many mental contexts as he can.
Nota - Posizione 170
x
Evidenzia (giallo) - Posizione 175
V. Comparing Theory and Phenomena
Nota - Posizione 175
T
Evidenzia (giallo) - Posizione 177
assumed that people say what they believe.
Evidenzia (giallo) - Posizione 177
people instead usually lie
Evidenzia (giallo) - Posizione 180
people usually have the strong impression that they are not lying,
Evidenzia (giallo) - Posizione 183
People sometimes accuse their opponents of insincerity, but rarely accept this same label as a self-description.
Evidenzia (giallo) - Posizione 191
Bayesians can easily disagree due to differing priors,
Evidenzia (giallo) - Posizione 192
Does this allow typical human disagreement to be rational?
Evidenzia (giallo) - Posizione 192
To answer this question, we would need to not only identify the prior differences that account for typical human disagreements, we would also have to decide if these prior differences are rational. And this last topic turns out to be very controversial.
Nota - Posizione 194
x
Evidenzia (giallo) - Posizione 195
To evaluate the honesty of disagreement, we do not need to know what sorts of differing priors are actually rational, but only what sorts of differences people think are rational.
Nota - Posizione 196
c
Evidenzia (giallo) - Posizione 198
VI. Proposed Rationality Constraints On Priors
Nota - Posizione 198
T
Evidenzia (giallo) - Posizione 203
An agent's prior describes the probability she would assign to each possible state if her information were reduced to knowing only that she was somewhere in that model’s universe of states.
Nota - Posizione 205
x COS È UN PRFIOR
Evidenzia (giallo) - Posizione 205
In such models, the prior is intended to describe each agent’s actual beliefs at this earlier time.
Nota - Posizione 206
c
Evidenzia (giallo) - Posizione 216
how different can rational priors be?
Evidenzia (giallo) - Posizione 217
One extreme position is that no differences are rational
Evidenzia (giallo) - Posizione 218
If John and Mary were witnesses to a crime, or jurors deciding guilt or innocence, it would be disturbing if their honest rational beliefs -- the best we might hope to obtain from them -- were influenced by personal characteristics unrelated to their information about the crime.
Nota - Posizione 220
ESEMPIO
Evidenzia (giallo) - Posizione 222
Another extreme position
Evidenzia (giallo) - Posizione 223
one prior is no more rational than another than one utility function is more rational than another.
Evidenzia (giallo) - Posizione 224
If we think we are questioning a prior, we are confused;
Evidenzia (giallo) - Posizione 228
One can accept this premise and still argue that priors should be treated as common.
Evidenzia (giallo) - Posizione 231
differences in terms of differing utilities
Evidenzia (giallo) - Posizione 231
rather than differing priors.
Evidenzia (giallo) - Posizione 236
People who think that some beliefs are irrational are thus forced to impose constraints on what priors are rational.
Evidenzia (giallo) - Posizione 237
For example, technically we can think of a person at different moments in time as different agents, and we can even think of the different mental modules within a person’s mind specializing in different mental tasks as different agents (Fodor 1983). If each different mental module at a different time could rationally have arbitrarily differing priors, then almost any sequence of belief statements a person might make might count as rational. Those who think that some sequences of statements are irrational must thus impose limits on how much priors can differ for agents close in space and time. For example, it is common to require that the different mental modules within a single person share the same prior. Since it is infeasible for mental modules to share more than a limited amount of information with each other, we understand that different mental modules will sometimes give conflicting answers due to failing to share relevant information.
Nota - Posizione 241
ES
Nota - Posizione 244
ES DI LIMITE: LA XSONA DEVE ESSERE COERENTE
Evidenzia (giallo) - Posizione 245
it is common to require Bayesians to change their beliefs by conditioning when they learn (or forget) information.
Nota - Posizione 245
ES DUE
Evidenzia (giallo) - Posizione 262
Psychologists explain human belief formation
Evidenzia (giallo) - Posizione 262
attitudes, information, and experiences,
Evidenzia (giallo) - Posizione 263
their mood,
Evidenzia (giallo) - Posizione 263
how a subject was first framed,
Evidenzia (giallo) - Posizione 264
what other beliefs were
Evidenzia (giallo) - Posizione 265
can easily produce an unending supply of independent persistent disagreements.
Evidenzia (giallo) - Posizione 265
How rational are such disagreements?
Evidenzia (giallo) - Posizione 266
Imagine that John believes that he reasons better than Mary, independent of any evidence for such superiority, and that Mary similarly believes that she reasons better than John.
Nota - Posizione 267
x
Evidenzia (giallo) - Posizione 270
Such priors are consistent in the sense that what John thinks he would believe if he were Mary, is in fact what Mary believes, no matter who “is” Mary. These priors are also “common” in the sense that everyone agrees about what Mary will think, no matter who really “is” Mary. These priors are not, however, “common” in the sense required for the theory of disagreement. Are such differing priors rational?
Nota - Posizione 273
c
Evidenzia (giallo) - Posizione 274
they violate “indexical independence.”
Evidenzia (giallo) - Posizione 275
things like whether the “I” that would ordinary say, “I am John,” instead says, “I am Mary.”
Evidenzia (giallo) - Posizione 277
our ordinary concepts of physical causation,
Evidenzia (giallo) - Posizione 278
For example, how likely John is to be right in his current argument with Mary may depend on John and Mary’s experience, IQ, and education, but given a rich enough set of such relevant features, we do not expect to get more predictive ability from indexical information about who really “is” Mary.
Nota - Posizione 280
x ES NN INDICIZZATO
Evidenzia (giallo) - Posizione 285
some theorists use considerations of the causal origins of priors
Evidenzia (giallo) - Posizione 286
If John and Mary have different priors, they should realize that some physical process produced that difference. And if that difference was produced randomly or arbitrarily, it is not clear that John and Mary should retain it.
Nota - Posizione 287
ES
Evidenzia (giallo) - Posizione 296
In summary, prior-based disagreements should be fully anticipated, and there are many possible positions on the question of when differing priors are rational. Some say no differences are rational, while others say all differences are rational. Many require agents close in space and time to have the same prior, but allow priors to differ at conception.
Nota - Posizione 298
SOMMARIO
Evidenzia (giallo) - Posizione 304
VII. Commonly Upheld Rationality Standards
Nota - Posizione 304
T
Evidenzia (giallo) - Posizione 310
sequence of statements that is inconsistent
Evidenzia (giallo) - Posizione 311
opinion does not change in response to relevant information.
Evidenzia (giallo) - Posizione 312
common priors for the mental modules within a person,
Evidenzia (giallo) - Posizione 313
people criticize others when their opinions appear to have self-serving biases.
Evidenzia (giallo) - Posizione 315
Consider a school administrator who
Nota - Posizione 315
ES
Evidenzia (giallo) - Posizione 316
favors his son for a school award, or a judge who does not excuse himself from a case in which he has an interest. Consider a manager who assigns himself to make an important sales presentation, or who uses his own judgment in an important engineering decision, rather than relying on apparently more qualified subordinates.
Nota - Posizione 319
c
Evidenzia (giallo) - Posizione 321
Though critics acknowledge that self-favoring belief is a natural tendency, such critics do not seem to endorse those beliefs as accurate or reliable.
Nota - Posizione 322
c
Evidenzia (giallo) - Posizione 323
common criticisms suggest that most people implicitly uphold rationality standards
Evidenzia (giallo) - Posizione 327
VIII. Truth-Seeking and Self-Deception
Nota - Posizione 327
T
Evidenzia (giallo) - Posizione 329
disagreements rarely embarrass us, and smarter people disagree just as often as others.14
Evidenzia (giallo) - Posizione 334
believing in yourself can be more functional that believing in logical contradictions.
Nota - Posizione 334
NN SIAMO TRUE SEEKERS
Evidenzia (giallo) - Posizione 336
while unbiased beliefs may be closer to the truth, self-favoring beliefs can better serve other goals.
Nota - Posizione 337
c
Evidenzia (giallo) - Posizione 337
The virtues of self-confidence and self-esteem are widely touted (Benabou and Tirole 2002). Parents who believe in their children care more for them, and the best salesmen believe in their product, whether it is good or bad. By thinking highly of himself, John may induce Mary to think more highly of John, making Mary more willing to associate with John. Scientists with unreasonably optimistic beliefs about their research projects may work harder and thus better advance scientific knowledge (Everett 2001; Kitcher 1990).
Nota - Posizione 339
x
Evidenzia (giallo) - Posizione 344
Self-favoring priors can thus be “rational” in the sense of helping one to achieve familiar goals,
Evidenzia (giallo) - Posizione 346
Regarding self-deception, people seem more likely to gain the benefits of biased beliefs if they do not believe that they are biased
Evidenzia (giallo) - Posizione 347
For example, a salesman is more persuasive when thinks he likes his product because of its features, rather that the fact that it is his product. And people do seem to often be unaware that they think highly of 22 themselves because of their prior. If Mary asks John to explain his high opinion of himself, John will usually point to some objective evidence, such a project he did well on.
Nota - Posizione 349
X ES
Evidenzia (giallo) - Posizione 355
academics who accept the conclusion that disagreement is irrational still disagree, including among themselves.
Evidenzia (giallo) - Posizione 356
When forced to overcome their self-deception and confront the issue, people consistently choose to continue to disagree.
Evidenzia (giallo) - Posizione 358
The story we have outlined so far, of a widely recognized tendency toward self-favoring beliefs in others, together with self-deception about this tendency in ourselves, is commonly told in psychology and philosophy. Evolutionary arguments have even been offered for why we might have evolved to be biased and self-deceived. 15 15 Many have considered the evolutionary origins of self-deception and excess confidence one’s own abilities (Waldman 1994). For example, truth-seekers who find it hard to lie can benefit by changing their beliefs (Trivers 1985; Trivers 2000). On topics like politics or religion, which are widely discussed but which impose few direct penalties for mistaken beliefs, our distant ancestors may have mainly demonstrated their cleverness and knowledge by inventing original positions and defending them well (Miller 2000).
Nota - Posizione 364
X PSICOLOGIA EVOLUZIONISTA
Evidenzia (giallo) - Posizione 365
This story is also commonly told in literature. For example, the concluding dream in Fyodor Dostoevsky's (1994 [1866]) Crime and Punishment seems to describe disagreement as the original sin, from which arises all other sins. In contrast, the description of the Houyhnhnms in Jonathan Swift’s (1962 [1726]) Gulliver’s Travels can be considered a critique showing how creatures (intelligent horses in this case) that agree too much lose their “humanity.”
Nota - Posizione 368
X LETTERATURA
Evidenzia (giallo) - Posizione 370
VIII. How Few Meta-Rationals?
Nota - Posizione 370
t
Evidenzia (giallo) - Posizione 371
he chooses his beliefs to be as close as possible to the truth.
Nota - Posizione 372
DEF TRUE SEEKERS
Evidenzia (giallo) - Posizione 372
put substantial weight on other goals
Nota - Posizione 372
NON TRUE SEEK
Evidenzia (giallo) - Posizione 373
he understands the basic theory of disagreement,
Nota - Posizione 373
DEF META RATIONALIST
Evidenzia (giallo) - Posizione 374
The theory of disagreement says that meta-rational people will not knowingly have self-favoring disagreements among themselves.
Nota - Posizione 375
x
Evidenzia (giallo) - Posizione 378
Our working hypothesis for explaining the ubiquity of persistent disagreement is that people are not usually meta-rational.
Nota - Posizione 379
x TESI
Evidenzia (giallo) - Posizione 380
people do not 24 typically seek only truth in their beliefs,
Evidenzia (giallo) - Posizione 381
People tend to be hypocritical
Evidenzia (giallo) - Posizione 382
How many meta-rational people can there be?
Evidenzia (giallo) - Posizione 385
If meta-rational people were common, and able to distinguish one another, then we should see many pairs of people who have almost no dishonest disagreements with each other. In reality, however, it seems very hard to find any pair of people who, if put in contact, could not identify many persistent disagreements.
Nota - Posizione 387
x
Evidenzia (giallo) - Posizione 388
Yet it seems that meta-rational people should be discernable via their conversation style.
Evidenzia (giallo) - Posizione 389
We know that, on a topic where self-favoring opinions would be relevant, the sequence of alternating opinions between a pair of people who are mutually aware of both being meta-rational must follow a random walk. And we know that the opinion sequence between typical non-meta-rational humans is nothing of the sort. If, when responding to the opinions of someone else of uncertain type, a meta-rational person acts differently from an ordinary non-meta-rational person, then two meta-rational people should be able to discern one another via a long enough conversation. And once they discern one another, two meta-rational people should no longer have dishonest disagreements.
Nota - Posizione 391
XSTILE RANDOM
Nota - Posizione 394
X CAMBIARE IDEA SPESSO
Evidenzia (giallo) - Posizione 396
it seems that the fraction of people who are meta-rational must be very small.
Evidenzia (giallo) - Posizione 405
only a tiny non-descript percentage of the population, or of academics, can be meta-rational.
Evidenzia (giallo) - Posizione 408
we each seem to have little grounds for confidence in our own meta-rationality,
Evidenzia (giallo) - Posizione 409
IX. Personal Policy Implications
Nota - Posizione 409
T
Evidenzia (giallo) - Posizione 413
Let us assume, however, that you, the reader, are trying to be one of those rare meta-rational souls in the world,
Evidenzia (giallo) - Posizione 420
never assume that you are more meta-rational than anyone else.
Evidenzia (giallo) - Posizione 421
Alternatively, you could adopt a "middle" opinion.
Evidenzia (giallo) - Posizione 424
we would want to construct a model of the process of individual self-deception,
Evidenzia (giallo) - Posizione 425
and infer where lies the weight of evidence,
Evidenzia (giallo) - Posizione 430
psychologists have found numerous correlates of self-deception. Self-deception is harder regarding one’s overt behaviors, there is less self-deception in a galvanic skin response (as used in lie detector tests) than in speech, the right brain hemisphere tends to be more honest, evaluations of actions are less honest after those actions are chosen than before (Trivers 2000), self-deceivers have more self-esteem and less psychopathology, especially less depression (Paulhus 1986), and older children are better than younger ones at hiding their self-deception from others (Feldman & Custrini 1988). Each correlate implies a corresponding sign of self-deception. Other commonly suggested signs of self-deception include idiocy, self-interest, emotional arousal, informality of analysis, an inability
Nota - Posizione 435
x AIUTO DALLA PSICOL EV
Evidenzia (giallo) - Posizione 442
recognizing the difficulty of this problem can at least make us a bit more wary of our own judgments when we disagree.
Evidenzia (giallo) - Posizione 445
X. Conclusion
Nota - Posizione 445
T
Evidenzia (giallo) - Posizione 452
We have therefore hypothesized that most disagreement is due to most people not being meta-rational, i.e., honest truth-seekers who understand disagreement theory and abide by the rationality standards that most people uphold. We have suggested that this is at root due to people fundamentally not being truth-seeking. This in turn suggests that most disagreement is dishonest.

venerdì 11 marzo 2016

HL ITALIANO Are Disagreements Honest? Tyler Cowen Robin Hanson

Are Disagreements Honest? Tyler Cowen Robin Hanson
  • ABSTRACT We review literatures on agreeing to disagree and on the rationality of differing priors, in order to evaluate the honesty of typical disagreements. A robust result is that honest truth-seeking agents with common priors should not knowingly disagree. Typical disagreement seems explainable by a combination of random belief influences and by priors that tell each person that he reasons better than others. When criticizing others, however, people seem to uphold rationality standards that disapprove of such self-favoring priors. This suggests that typical disagreements are dishonest. We conclude by briefly considering how one might try to become more honest when disagreeing.
  • I. Introduction
  • MATERIE. politics, morality, religion, and relative abilities.
  • OBIETTIVITÀ. they often consider their disagreements to be about what is objectively true, rather than about how they each feel or use words.
  • people often consider their disagreements to be honest...Yet according to well-known theory, such honest disagreement is impossible.
  • Robert Aumann (1976) first developed general results about the irrationality of “agreeing to disagree.”He showed that if two or more Bayesians would believe the same thing given the same information (i.e., have “common priors”), and if they are mutually aware of each other's opinions (i.e., have “common knowledge”), then those individuals cannot knowingly disagree. Merely knowing someone else’s opinion provides a powerful summary of everything that person knows, powerful enough to eliminate any differences of opinion due to differing information.
  • One of Aumann’s assumptions, however, does make a big difference. This is the assumption of common priors... While some people do take the extreme position that that priors must be common to be rational, others take the opposite extreme position, that any possible prior is rational.
  • TESI. We will tentatively conclude that typical disagreements are best explained by postulating that people have self-favoring priors, even though they disapprove of such priors, and that self-deception usually prevents them from seeing this fact.
  • II. The Phenomena of Disagreement
  • Disagreements do not typically embarrass us.
  • and high-IQ individuals seem no less likely to disagree than others. Not only are disagreements not embarrassing, more social shame often falls on those who agree too easily, and so lack “the courage of their convictions.”
  • Psychologists suggest that human disagreements typically depend heavily on each person believing that he or she is better than others
  • People are usually more eager to speak than they are to listen,
  • For example, most people, especially men, estimate themselves to be more able than others
  • Gilovich (1991, p.77) cites a survey of university professors, which found that 94% thought they were better at their jobs than their average colleagues.
  • III. The Basic Theory of Agreeing to Disagree
  • Imagine that John hears a noise, looks out his window and sees a car speeding away. Mary also hears the same noise, looks out a nearby window, and sees the same car.... John and Mary’s immediate impressions about the car will differ, due both to differences in what they saw and how they interpreted their sense impressions. John’s first impression is that the car was an old tan Ford, and he tells Mary this. Mary’s first impression is that the car was a newer brown Chevy, but she updates her beliefs upon hearing from John. Upon hearing Mary’s opinion, John also updates his beliefs. They then continue back and forth, trading their opinions about the likelihood of various possible car features... If Mary sees John as an honest truth-seeker who would believe the same things as Mary given the same information... then Mary should treat John’s differing opinion as indicating things that he knows but she does not. Mary should realize that they are both capable of mistaken first impressions. If her goal is to predict the truth, she has no good reason to give her own observation greater weight, simply because it was hers. Of course, if Mary has 20/20 eyesight, while John is nearsighted, then Mary might reasonably give more weight to her own observation. But then John should give her observation greater weight as well.
  • If John and Mary repeatedly exchange their opinions with each other, their opinions should eventually stop changing, at which point they should become mutually aware (i.e., have “common knowledge”) of their opinions
  • A more detailed analysis says not only that people must ultimately agree, but also that the discussion path of their alternating expressed opinions must follow a random walk.
  • Yet in ordinary practice, as well as in controlled laboratory experiments (Hanson and Nelson 2004), we know that disagreement is persistent.
  • IV. Generalizations of the Basic Theory
  • Thus John and Mary need not be absolutely sure that they are both honest, that they heard each other correctly, or that they interpret language the same way.
  • The beliefs of real people usually depend not only on their information about the problem at hand, but also on their mental context, john should pay attention to Mary's opinion not only because it may embody information that John does not have, but also because it is the product of a different mental context, and John should want to average over as many mental contexts as he can.
  • V. Comparing Theory and Phenomena
  • The stylized facts of human disagreement are in conflict with the above theory of disagreement.
  • The theory above implicitly assumed that people say what they believe.
  • people usually have the strong impression that they are not lying, and it hard to see how people could be so mistaken about this.... People sometimes accuse their opponents of insincerity, but rarely accept this same label as a self-description.
  • RAZIONALITÀ COME ONESTÀ. Bayesians can easily disagree due to differing priors, regardless of whether or not they have differing information, mental contexts, or anything else. Does this allow typical human disagreement to be rational?.. we would also have to decide if these prior differences are rational. And this last topic turns out to be very controversial.
  • To evaluate the honesty of disagreement, we do not need to know what sorts of differing priors are actually rational, but only what sorts of differences people think are rational.
  • VI. Proposed Rationality Constraints On Priors
  • In general, Bayesian agents can have beliefs not only about the world, but also about the beliefs of other agents, about other agent’s beliefs about other agents, and so on.
  • common knowledge among Bayesians. Thus when priors differ, all agents know those differences, know that they all know them, and so on. So while agents with differing priors can agree to disagree, they must anticipate such disagreements.
  • But how different can rational priors be? One extreme position is that no differences are rational (Harsanyi 1983, Aumann 1998). The most common argument given for this common prior position is that differences in beliefs should depend only on differences in information.
  • Another extreme position is that a prior is much like a utility function: an ex post reconstruction of what happens, rather than a real entity subject to independent scrutiny.
  • one prior is no more rational than another than one utility function is more rational than another.
  • A consequence of this is that if there are no constraints on which priors are rational, there are almost no constraints on which beliefs are rational. People who think that some beliefs are irrational are thus forced to impose constraints on what priors are rational.
  • it is common to require Bayesians to change their beliefs by conditioning when they learn (or forget) information.
  • Finally, some theorists use considerations of the causal origins of priors to argue that certain prior differences are irrational.
  • In summary, prior-based disagreements should be fully anticipated, and there are many possible positions on the question of when differing priors are rational. Some say no differences are rational, while others say all differences are rational.
  • VII. Commonly Upheld Rationality Standards
  • Most people have not directly declared a position on the subject of what kinds of prior differences are rational.
  • people who feel free to criticize consistently complain when they notice someone making a sequence of statements that is inconsistent or incoherent. They also complain when they notice that someone’s opinion does not change in response to relevant information.
  • Perhaps even more frequently, people criticize others when their opinions appear to have self-serving biases.
  • Though critics acknowledge that self-favoring belief is a natural tendency, such critics do not seem to endorse those beliefs as accurate or reliable.
  • These common criticisms suggest that most people implicitly uphold rationality standards that disapprove of self-favoring priors,
  • VIII. Truth-Seeking and Self-Deception
  • Non-truth-seeking and self-deception offer two complementary explanations for this difference in behavior. First, believing in yourself can be more functional that believing in logical contradictions. Second, while it is hard to deny that you have stated a logical contradiction, once the contradiction is pointed out, it is much easier to deny that a disagreement is due to your having a self-favoring prior.
  • Scientists with unreasonably optimistic beliefs about their research projects may work harder and thus better advance scientific knowledge (Everett 2001; Kitcher 1990).
  • Self-favoring priors can thus be “rational”in the sense of helping one to achieve familiar goals, even if they are not “rational”in the sense of helping one to achieve the best possible estimate of the true situation (Caplan 2000).
  • Evolutionary arguments have even been offered for why we might have evolved to be biased and self-deceived.
  • This story is also commonly told in literature. For example, the concluding dream in Fyodor Dostoevsky's (1994 [1866]) Crime and Punishment seems to describe disagreement as the original sin, from which arises all other sins. In contrast, the description of the Houyhnhnms in Jonathan swift (1962 [1726]) Gulliver’s Travels can be considered a critique showing how creatures (intelligent horses in this case) that agree too much lose their “humanity.”
  • VIII. How Few Meta-Rationals?
  • We can call someone a truth-seeker if, given his information and level of effort on a topic, he chooses his beliefs to be as close as possible to the truth. A non-truth seeker will, in contrast, also put substantial weight on other goals when choosing his beliefs.
  • Let us also call someone meta-rational if he is an honest truth-seeker who chooses his opinions as if he understands the basic theory of disagreement... and abides by the rationality standards that most people uphold, which seem to preclude self-favoring priors.
  • TESI. Our working hypothesis for explaining the ubiquity of persistent disagreement is that people are not usually meta-rational.
  • How many meta-rational people can there be?
  • If meta-rational people were common, and able to distinguish one another, then we should see many pairs of people who have almost no dishonest disagreements with each other.
  • Yet it seems that meta-rational people should be discernable via their conversation style.
  • two meta-rational people should be able to discern one another via a long enough conversation. And once they discern one another, two meta-rational people should no longer have dishonest disagreements.
  • unless meta-rationals simply cannot distinguish each other, only a tiny non-descript percentage of the population, or of academics, can be meta-rational. Either few people have truth-seeking rational cores, and those that do cannot be readily distinguished, or most people have such cores but they are in control infrequently and unpredictably.
  • IX. Personal Policy Implications
  • Let us assume, however, that you, the reader, are trying to be one of those rare meta-rational souls in the world,
  • One approach would be to try to never assume that you are more meta-rational than anyone else.
  • Alternatively, you could adopt a "middle" opinion. There are, however, many ways to define middle, and people can disagree about which middle is best
  • psychologists have found numerous correlates of self-deception. Self-deception is harder regarding one’s overt behaviors, there is less self-deception in a galvanic skin response (as used in lie detector tests) than in speech, the right brain hemisphere tends to be more honest, evaluations of actions are less honest after those actions are chosen than before (Trivers 2000), self-deceivers have more self-esteem and less psychopathology, especially less depression (Paulhus 1986), and older children are better than younger ones at hiding their self-deception from others (Feldman & Custrini 1988). Each correlate implies a corresponding sign of self-deception. Other commonly suggested signs of self-deception include idiocy, self-interest, emotional arousal, informality of analysis, an inability
  • While we have identified some considerations to keep in mind, were one trying to be one of those rare meta-rational souls, we have no general recipe for how to proceed. Perhaps recognizing the difficulty of this problem can at least make us a bit more wary of our own judgments when we disagree.
  • X. Conclusion
  • We have therefore hypothesized that most disagreement is due to most people not being meta-rational, i.e., honest truth-seekers who understand disagreement theory and abide by the rationality standards that most people uphold. We have suggested that this is at root due to people fundamentally not being truth-seeking. This in turn suggests that most disagreement is dishonest.
continua