Is there an expected useful outcome for challenging every statement? "My favorite dessert is chocolate cake" can be countered with "I've seen you choose apple pie instead of chocolate cake for dessert the last 3 of 5 times". But so what? Why do you think your limited observations trump the speaker's more complete knowledge enough to force an argument at that point?
It doesn't sound like you've used feedback from your previous arguments in order to determine if you indeed have enough information to have a meaningful counter-argument. Doubt fuels empiricism, not rationalism.
There's also an opportunity cost. "The Vikings made it to North America" can be challenged with "but the Norse of Greenland weren't really Vikings", inviting a competitive but ultimately bland argument about various etymological nuances, when the speaker actually wanted to bring up the latest archeological finds on Baffin Island. The speaker may be less likely to talk with you in the future about interesting ideas, to avoid being dragged into inane debates.
There's also the possibility that you are being deliberately distracted. A reflexive challenge means you only really consider the surface arguments, and not the underlying premise. If someone says that Agile is better than Waterfall, your response could be to point out cases where Waterfall is better, without realizing how that discussion tends to assume the creation myth of Agile, constructed on a false narrative of history. (See http://www.infoq.com/articles/bossavit-agile-ten-years-on .)
Statements are data points, not debate points. You may feel like you need to respond to them at once. Or you can collect them, use to them test and refine your hypotheses about what the other person is saying, and estimate if it's useful enough to voice a contrary opinion.
Other causes worth examining: ego (desire to prove one's intelligence), one-up-manship (desire to harm/contradict/take down arguments of others), deficiency (not observing feelings of others or not addressing the end-goal of the task in favour of hair splitting), hedonism (argument gives you pleasure no matter the consequences for the task or others) etc.
Contrarians can be intolerable team members so it requires care to harness and channel an analytical mind and not let it be driven by base and counter-productive motivations. Its very easy not to notice and stick with a seductive virtuous justification for bad behaviour.
Applying the method to a verbal argument: "You never listen!" "That's not true, I'm listening now!" Yes, I think it is very annoying. :)
> I notice when my mind is arguing for a side (instead of evaluating which side to choose), and flag this as an error mode. (Recent example from Anna: Noticed myself explaining to myself why outsourcing my clothes shopping does make sense, rather than evaluating whether to do it.)
I did (although, as I noted, I think that part of being rational is critically creating your own criteria for rationality, rather than using someone else's). I also was not claiming that this was not on the list—but:
> I notice when my mind is arguing for a side (instead of evaluating which side to choose), and flag this as an error mode.
Although logically—well, in classical logic, anyway—every argument against something is an argument for its opposite, I think that there is nonetheless a meaningful difference between making a contrarian argument (as I do; it is an essentially negative process) and arguing for the opposite position (an essentially positive process).
I am confidant that any attempt to rule out the third possibility will fail.
> I am confidant that any attempt to rule out the third possibility will fail.
To be sure, as the highly rational being that I am :-), I recognise that it is annoying; my question is whether it is just annoying, i.e., without any corresponding benefit.
I find De Bono's six thinking hats as a nice way to view how best to work rationally in a team. Contrarians only have one hat and miss the other five.
The problems I have seen include:
dominating discussion (a contrarian has something to argue in every situation, sometimes you need to cover some ground in broad strokes to get some feel of whats involved but a contrarian latches on the first point of uncertainty),
off-topic (to stray from the high priority issue to argue in depth some low priority secondary issue),
arguing from ignorance (they see argument as 'their way of learning' but in a group situation its very selfish, they should take effort to become better informed offline)
negativity (its unrelentingly depressing and critical - picking holes and killing any newborn idea that might need some nurturing before looking at more critically otherwise you can give up on it too soon)
personality clashes (there will be inevitable issues of butting heads with different personality types who feel criticism personally or consider arguments as fights or need negatives presented in a status aware manner etc.)
Something that might concern you is that reflexive contrarians are very predictable and hence exploitable. The manipulator can basically dangle a designed target in front of them and the contrarian will say whatever is wanted. Reflex is not going to be rational at a high level because the frame its operates in is too narrow and shallow.
* that it is just annoying
Of course, Messrs. Carrey and Daniels have a proof by demonstration that the just annoying ( http://www.wavlist.com/movies/032/dumb-annoy.wav ) can get two million views on YouTube; which may be a corresponding benefit.
In this spirit, I have an infuriating (to others) habit of reflexively arguing against someone else's position. (It was originally born out of the "search for counterexamples" mindset of a mathematician, but now it's an unconscious behaviour.) This habit is so comically ingrained that, if the person to whom I make this argument switches his or her position, then I will in turn switch to arguing for the original position.
I don't know whether this counts as highly rational, highly contrarian, or just annoying.