Thanks - I should have checked the link more carefully. The links were more for illustration anyway.

Lots of people have claimed that we have a pessimism bias, and my post obviously assumes they are right, but it would be nice to see some proper empirical work on the issue.

"The standard view is of course that [radicals] want radical change because they believe that the world has got worse, but I think that to some extent, the causality is reversed: they believe that the world has got worse because they want radical change."

This, however, is very insightful.

Thanks!