1. Peak-end bias What we remember is different to what we
experience
2. A group of patients had colonoscopies (Group A) They were
asked to record their pain on a scale of 1 - 10 throughout the
procedure
3. Good afternoon Mr Jones
4. You may experience a little discomfort
5. Brace yourself!
6. Ooh!
7. Heres a graph of the pain recorded by Group A Pain 0 2.5 5
7.5 10 Time Area under graph = total pain
8. A second group of patients also had colonoscopies (Group B)
They were also asked to record their pain on a scale of 1 - 10
throughout the procedure
9. Good afternoon Mr Smith
10. You may experience a little discomfort
11. Brace yourself!
12. Hrrmphh!
13. Heres a graph of the pain recorded by Group B Pain 0 2.5 5
7.5 10 Time Area under graph = total pain
14. After the colonoscopy had finished, each group was asked to
evaluate how much pain they had suffered.
15. Pain 0 2.5 5 7.5 10 Time Heres a reminder of their recorded
pain Pain 0 2.5 5 7.5 10 Time Group B Group A Area under graph =
total pain Area under graph = total pain
16. Which group do you think said that they had suffered
more?
17. Group A How much pain did you experience?
18. or Group B? How much pain did you experience?
19. Group B - said they had it worse, even though they had in
fact experienced less total pain
20. Group B - said they had it worse, even though they had in
fact experienced less total pain Pain 0 2.5 5 7.5 10 Time Pain 0
2.5 5 7.5 10 Time Area under graph = total pain Area under graph =
total pain Group A Group B
21. Why?
22. Why? Even though Group B experienced less total pain, we
tend to recall events by focusing on our peak and end experiences.
Both groups had experienced the same peak levels of pain, but Group
As colonoscopy ended less painfully
23. Reference Patients memories of painful medical treatments:
real-time and retrospective evaluations of two minimally invasive
procedures Donald A. Redelmeier and Daniel Kahneman 1996 Pain 116,
3-8
