There are two reasons people change their stories. One is that they once believed something, but later discovered they were in error and now say something else

There are two reasons people change their stories. One is that they once believed something, but later discovered they were in error and now say something else they believe to be true. The other is that they don't care about what's actually true, and are just saying whatever they think will engage or impress their listeners. Frankfurt's "On Bullshit" is a readable survey of this topic. The second kind is far more common. But the first kind is really important. When someone updates their views we should pay attention. Perhaps a member of the rationalist community could prove this using Bayes theorem.