Lectures and Colonoscopies

by Site Author

In the mid-1990s, a group of patients went to the hospital for a colonoscopy. They underwent the usual procedure, but with one hitch. Some patients were randomized to have a “short interval added to the end of their procedure during which the tip of the colonoscope remained in the rectum.”

Those patients were thus given a longer procedure, with a few minutes at the end during which the pain was only moderate. Objectively, they should have remembered the entire experience as worse, since their procedure was longer. But, actually, those in the treatment group rated the entire procedure as less painful. As Redelmeier, Katz, and Kahneman put it: “adding a short interval of minimal discomfort to the final moments of the procedure caused patients to retain a more favorable… overall memory of the experience.”

The experiment—and many others—suggests that our memory can be deceptive. When thinking back on experiences, the last part of the experience tends to disproportionately dominate. Psychologists call this the peak-end rule. Wikipedia’s definition: “this heuristic process leads people to judge an experience by its most intense point and its end, as opposed to the total sum or average of every moment of the experience.”

It is useful to know that our memories are fallible like this. I know someone whose parents always tried to end family vacations with a bang. They would spend a week at ordinary hotels, and then spend one or two nights in a luxury hotel. The last two days of the trip would cost more than the rest of the trip combined.

I try to do something similar when I plan out my lectures. I always end lectures with a story. The boring details—technical points, homework, grades—I discuss during the middle of class.

The peak-end rule also dictates how magazine articles are written. Articles in The New Yorker always begin with an anecdote. The articles sometimes cover quite a bit of boring ground, but never in the beginning or at the end.

The same ought to apply to blog posts. All blog posts should begin with an anecdote and end with a bang.