So it does depend on what you mean by rationalist.
I think it is vastly more likely that those who feel like everything they say is incredibly important might just be idiots who self identify as rationalists, and those who are rationalists are doing more thinking than broadcasting.
You could say there is little overlap between people who are good at basketball and those who say they are good at basketball.
That statement does not have any effect on your ability to judge them by watching them play.
Right, one could make that statement. It would be silly, but they could make it. I think most people who consider themselves good at basketball are probably better than average at basketball.
> That statement does not have any effect on your ability to judge them by watching them play.
Is the notion that someone who's not good at basketball can't recognize a good basketball player?
I'm a little confused by your metaphor.
I should note that you changed the statement from say to consider themselves. It is entirely possible (and rather frequent) for people who do not consider themselves good at basketball to say that they are. People who actually are good at basketball quite often do not feel the need to say so, because it is apparent when they play.
I can change "consider themselves to be rationalists" to "say they are good at basketball" because that is just a change of premise. It leaves the structure the same.