«[...] What Kahneman did was, randomly, to lengthen the procedure for half of the 682 patients with an extra terminal minute, in which the colonoscope, before being extracted, remained stationary. It was uncomfortable, but not terribly painful.
Very simply, those who had the extra minute (irrespective of how excruciating the earlier part of the operation had been) had a consistently more favourable reaction afterwards and were much more likely to elect for colonoscopy again, rather than barium and x-ray. Ask someone who didn't have the extra minute what it was like and they were likely to reply: "It was hell - like being raped by an unlubricated fire hose." Ask someone who did have the extra minute and the answer tended to be, "Not so bad".
There is, Kahneman deduced, a durational element in how we evaluate our experiences. The last level of pain, or pleasure, conditions what we remember of the whole event - our verdict on it, so to speak. For economists, this has useful applications in predicting decision-making, and the "shortcuts" most of us employ in the hundreds of such decisions we make every day. [...]»