Ok, so let's keep going from there. I mean, it ought to be intuitive, with everyone having a favorite personal example, that groups of people seem pretty able to sustain very flagrantly wrong, and even downright stupid, beliefs over long periods of time. So a theory of socially distributed cognition should ideally either explain how this happens, or explain it away as an unfortunate side-effect of rational thinking in ambiguous situations (like certain optical illusions and the Bayesian brain theory).

One mechanism I've heard posited (by Friston's neurosci lab) for how humans deal with noisy environments is to weight our sensory inputs by their expected precision. I might look at the ocean's surface and expect to see a froth of sea-foam, particulate matter, and water, so I won't pay enough attention to see a camouflaged fish. I'll still notice if Godzilla walks up out of it, though.

Would a similar precision-weighting mechanism help to model social trust, and to thus give us an idea of how groups can fixate on incorrect group-beliefs? Are people treating outgroup members or "opponents", so to speak, as uselessly noisy, and thus down-weighting any need to update based on what those persons say or do? Could this contribute to people's (supposed) occasional failures to accurately model their outgroups, since they're intuitively modelling those outgroups precisely as mostly outputting random noise rather than precise information?