In his recent Why feeling more pain may be better for you, Tom Stafford reminds us of the classic Kahneman study which yielded both the Peak End rule and succor to sadistic proctologists.
If that description didn't tempt you to go read the column, here's the super short version: Kahneman found that when asked how bad a painful experience was, people recall (roughly) the average of how bad it was at it's worst --the 'peak'-- and how bad it was at the end --the, uh, 'end'. This, Kahneman claims, raises a real ethical dilemma:
Imagine a physician conducting a colonoscopy; the patient is in intense pain. The examination is complete and the physician could terminate the procedure now, providing instant relief --and a permanently negative evaluation of the whole episode. Should the physician seek the patient's consent to extend the pain for a while in order to form and retain an improved opinion of the procedure….a patient who has had two otherwise identical procedures that differ in the abruptnees of relief will prefer [the one with] more total pain but provides a better end….When the experiencing self and the remembering self disagree, whom are we to believe? (1994, p.21)
Stafford doesn't answer this question. Rather he turns to the Peak-End Rule as a broader phenomena (as other research shows) to make a different point
"But I think the most important lesson of the Peak-End experiments is something else. Rather than saying that the duration isn't important, the rule tells me that it is just as important to control how we mentally package our time. What defines an “experience” is somewhat arbitrary. If a weekend break where you forget everything can be as refreshing as a two-week holiday then maybe a secret to a happy life is to organise your time so it is broken up into as many distinct (and enjoyable) experiences as possible, rather than being just an unbroken succession of events which bleed into one another in memory."
I have to politely demur on what's the most interesting lesson. I've spent the last 10 years ---my entire professional career thus far--- thinking about some of the deep philosophical issues Kahneman's question raises.
Presumably, as Kahneman notes, none of us as patients would agree (while in pain) to the physician prolonging our pain. But we would then look jealously upon our friend whose doctor didn't ask her permission and whose colonoscopy was (as she recalls it) easier than our own. From our deathbed perspectives, my life contained more suffering. It was in that respect worse than hers.
Of course, we're both mistaken about how our total suffering compares. Arguably, in some cases, our lives can be better or worse than we believe them to be. If your loved ones' affection had been a cruel facade behind which they constantly ridiculed you, even though you never found out, your life was still worse than you thought it was. But are mistakes about how much we suffered like this?
Look at what's going on here. We need to decide what makes pain bad. We need to figure out how to aggregate goods (e.g., do we simply add up the good and bad?). We need to understand what constitutes human well-being ---to decide what makes a life as a whole good. We need to deal with organic unities (i.e., whether the arrangement of a good and a bad may yield an overall value that's different from the simple sum --schadenfreude is a common example). We need to deal with the asymmetries of past and future pains. Indeed, this road takes us straight to fundamental questions about the nature of intrinsic value. (That's the road I followed to my dissertation)
John Broome took this issue up in his 1996 'More pain or less?' with the straightforward claim that the person's mistaken evaluations are irrelevant. Pains are intrinsically bad. There should be less of it.
Stephanie Beardman who was finishing up at Rutgers just as I entered, came up with a more sophisticated response in her The choice between current and retrospective evaluations of pain (here's a pdf). In it she sets out several alternative interpretations of Kahneman's results and articulates some ways in which our preferences about past experiences may be more sophisticated than they at first seem.
Since she does a lot of what philosophers do best ---laying out the conceptual territory--- some of you empirically-minded folks may find it a useful source for developing uninvestigated hypotheses. It's also just a very nice gateway to some of the deep philosophical issues lurking just beneath the surface of seemingly easy questions. (Though be forewarned, it's a gateway drug too. A few early conversations with Stephanie definitely played a role in my getting hooked). In any event, you should read it.