Yup, those charts puzzle me, too (based on about five seconds of analysis, admittedly, but I have a strong preexisting belief that there are many examples of such silliness on the Internet, so I'm strongly inclined to agree that this particular chart is yet another example... which is of course yet another example of the kind of judgment-based-on-non-analytical factors we're discussing).
How confident are you that this is how all persuasion works?
I don't know how general this is, but I do think it's an important factor that I don't see discussed.
Another point is peer effects. I remember at school my physics teacher used to use proof by intimidation where he would attempt to browbeat and ridicule students into agreeing with him on some subtly incorrect argument. And he wouldn't just get agreement because he scared people, the force of his personality and the desire to not look foolish would genuinely convince them. And then he'd get cross for real, saying no, you need to stand up for yourself, think...
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.