crackpot people and crackpot ideas
I listened to Brian Doherty talk about his book on the history of libertarianism. One point he makes is that in the forties and the fifties, libertarians were mostly crackpots. He suggests that this is likely to be the case for any dissident idea.
This suggests that different ideas are going to occupy different niches. For example, suppose that there is a large niche for anti-capitalist ideas. The actual ideas occupying that niche may be different in different time periods, but something always fills that niche.
There may different niches for pessimistic ideas and optimistic ideas.
When there is a popular idea and a crackpot idea, which is more likely to be right? Instead of thinking about this problem by thinking in terms of a probability distribution, it may be useful to think of an ecological model. What sort of false ideas are likely to occupy particular niches, including the niche of popular opinion? What sort of false ideas are likely to survive by finding crackpots to host them?
Belief in anthropogenic global warming is becoming popular. Skepticism is becoming crackpot. What is the probability that the global warming partisans will turn out to be the crackpots? How does that probability depend on the niche that the global warming idea occupies?
I know that the ecological metaphor has been used in this context, with the term "meme," but I admit I have never read the literature, so I don’t know if the connection between bias and survival of memes has been addressed there.
IMO, the biggest reasons are the three fundamental premises we make - that everyone's brain works (thinks) the same as ours, that we are entirely conscious of our thought processes and that what we sense is reality. Therefore, everyone should reach the same conclusions, hold the same opinions and act as we do, sitting here with our model of how the world works (which we assume is shared in virtually its entirety).
If they do not, we then assume it is most likely because (in descending order of likelihood) they are devious (they know better but they have bad motives - greed, lazy, . . .), they are stupid (they can't think any better), they have a knowledge gap (our knowledge is more perfect and theirs is weak so they don't know any better) or that they are nuts and such is to be expected of them.
To discover (diagnose) where their thinking went wrong and to decipher their motives, we run the VCR backwards from what we saw through our model of how the world works to what we would have to be thinking, have as motives or know if we behaved or acted that way or stated that.
Then to "fix" them, providing we haven't concluded they are nuts and thus unfixable, we run the VCR forward, adding in the ingredients that we think we would personally need to move from their erroneous state of mind to better reflect our correct state of mind.
Hence, when we all know something, those skeptical of the conclusion are either crackpots (ignorable nuts) or devious villans to be fixed. Devious villans are best moved by stoning or other forms of public correction and humiliation.
Crackpot ideas survive by being dismissed by people who know better and by developing credible sounding arguments beyond the level of lay debate. I can think of several examples of arcane or taboo knowledge where this is the case. I agree that any idea must survive in a kind of ecology that is supportive of it.