Here’s the gist of the result (which was obtained by studying samples of US residents recruited online).
People often don’t understand political issues fully, yet have strong convictions about them. When subjects were asked to go into state-and-defend mode on a political issue (i.e., asked to state their view and then give their reasons for holding it), their conviction was entrenched and their misunderstandings went unnoticed.
But if asked to explain, or talk through, how the policy, position, etc. they defend would actually work, people were significantly more likely to appreciate what they did not fully understand, and to stop being so entrenched in their opinions.
This kind of information could be a huge deal for philosophical methodology. There are many issues (political and otherwise) that philosophers discuss which we do not fully understand, yet have strong convictions about.
State-and-defend mode is so common in our discipline. What if it is seriously hindering our progress by entrenching us in views we do not really understand, while concealing our own misunderstandings from us?