Right, it seems like people actually have instincts for bad mental posture more than for good mental posture.

Still, I think it might not be too difficult to look at ourselves and determine when we are using good mental postures and bad ones.

For example, consider conversations. Pretty much everyone has had good conversations and bad conversations. In the bad ones, they degenerate (in the worst cases) into you and your conversational partner straight out contradicting each other, insulting each other, talking about each other's motivations and unreasonableness, and so on. In the good ones, each of you point out the good points made by the other and very possibly converge on something close to the truth. In the best conversations I've had, sometimes one of us reversed his position and jumped to defending a position more extreme than the one held by the other -- exactly the kind of "absurdity" predicted by Aumann's agreement theorem for rational conversation partners.

And we usually know even while it's happening whether we're engaging in the reasonable kind of conversation or the unreasonable kind.