[brandmeyer]

I think you're right. Take a look at the before/after curves for "this is what the predictions look like after the papers".

The before curves are gaussian+ distributed and pessimistic, but the after curves are all distinctly bimodal (or worse). This suggests that some population of the participants were broadly pessimized by their surveys and another population was broadly optimized by their surveys.

This could instead be a measurement of how people's trust in science is predicated on how well it matches their own prior beliefs.

+ A sharper eye shows they aren't quite bimodal in the prior belief. Even in those cases, the separation between the modes gets much wider.