That people are overconfident doesn't imply that they are more overconfident when they go against the majority opinion. Investors that think too much they can beat the market receive lower return, but the market is probably smarter than the majority opinion.
I would even say that the pressure to conform is so strong that most people will be much more overconfident when they go with the wisdom of the crowd. Could it be that as participants to a blog dedicated to rationality we are more overconfident and we resist the common opinion too much? It could, but I'd like to see some evidence.
“Everyone complains of his memory, but nobody of his judgment." This maxim of La Rochefoucauld rings as true today as it did back in the XVIIth century. People tend overestimate their reasoning abilities even when this overconfidence has a direct monetary cost. For instance, multiple studies have shown that investors who are more confident of their ability to beat the market receive lower returns on their investments. This overconfidence penalty applies even to the supposed experts, such as fund managers.
So what an expert rationalist should do to avoid this overconfidence trap? The seeming answer is that we should rely less on our own reasoning and more on the “wisdom of the crowds”. To a certain extent this is already achieved by the society pressure to conform, which acts as an internal policeman in our minds. Yet those of us who deem themselves not very susceptible to such pressures (overconfidence, here we go again) might need to shift their views even further.
I invite you now to experiment on how this will work in practice. Quite a few of the recent posts and comments were speaking with derision about religion and the supernatural phenomena in general. Did the authors of these comments fully consider the fact that the existence of God is firmly believed by the majority? Or that this belief is not restricted to the uneducated but shared by many famous scientists, including Newton and Einstein? Would they be willing to shift their views to accommodate the chance that their own reasoning powers are insufficient to get the right answer?
Let the stone throwing begin.