Re: Opinions as Evidence
Fri, 28 Mar 1997 00:35:45 -0500 (EST) (Robin Hanson) writes:

>Michael Lorrey responded:
>>Try these: [as candidates for persitent disagreement on fact]
>>JFK assasination
>>Roswell Incident
>>MLK assasination
>>Why we "lost" Vietnam
>>The abortion controversy
>>The Philadelphia Experiment
>>The Holocaust
>>the Rosenberg Trial
>>the Alger Hiss trial
>>Contragate (esp. Ollie North)
>>the Big Bang
>>the Second Amendment
>>any questions?

Rather an inflammatory list.

>Yes. We need more detail about these to evaluate their relevance.
I think everybody here is passably familiar with these issues. Enough so to

>>Specifically, we need to see that:
>1. There are (at least) two communities, each aware of the other's views.

True for all of the above.

>2. These views are relatively stable and substantially different.

Also true.

>3. These views reflect actual beliefs, not just verbal posturing.

True for most believers, at least.

>4. The dispute has lasted long enough so both sides know that
> both sides know that both sides know (etc.) ... that they disagree.

True for all of the above.

>5. Both sides see the issue as a dispute over fact, not values, and
> believe that the other side does as well.

True for all of the above save Vietnam, abortion, and the Second Amendment,
and partially true even for them.

>6. We can't easily dismiss one group as small and primarily composed of
> people who are much more "cognitively broken" than most.

The Holocaust controversies are the work of relatively small groups of kooks.
But most of these do indeed have large numbers of reasonably intelligent
people on both sides.

>7. We can't easily dismiss the type of issue as exceptional in
> inducing "broken cognition" even in ordinary people.

Religion is the only "exceptional" item involved in these issues in that it
obviously clouds otherwise reasonable people's minds. But religions are
important things, believed by most people in all societies I'm aware of.
It's exceptional in its effect, but the rule in its presence.

>This is the sort of example needed to suggest that ordinary people in
>ordinary contexts often have persistent disagreements contrary to
>Bayesian expectations.

All the literature on human reasoning I'm aware of indicates the people have
many blatant errors in their reasoning, especially with respect to
probabilities (particularly important to Bayesian inference, which is based
on modifying probabilities of conflicting theories.) What evidence is there
that *any* people, never mind ordinary ones, act like good Bayesian agents,
apart from in science?