1. An Exploration of Decision Processes in an Evolutionary Perspective: the Case of the Framing Effect

2. Neo- Darwinism Cognitive psychology Introduction (1) Evolutionary psychology Evolutionary Psychology

3. Introduction (2) Evolutionary psychology Evolution Evolution too Non-human cognitionHigh level cognition

4. Introduction (3) Decision making “Making decision is like speaking prose - people do it all the time, knowingly or unknowingly”

5. Introduction (4) Asian disease 72% Imagine that the U.S. is preparing for the outbreak of an unusual Asian disease, which is expected to kill 600 people. Two alternative medical plans to treat the disease have been proposed. Assume that the exact scientific estimates of the consequences of the plans are as follows: - If plan A is adopted, 200 people will be saved. - If plan B is adopted, there is a one-third probability that all 600 people will be saved and a two-thirds probability that none of them will be saved. which of the two programs would you favour ?

6. –Plan A = 200 * 100% = 200 –Plan B = 600 * 33% + 0 * 67% = 200 On an infinite number of choices and random checks, both plans would save, on the average, the same number of people. There is no “good answer” to the Asian disease problem. Introduction (5) Asian disease

7. Introduction (6) Asian disease 78% Imagine that the U.S. is preparing for the outbreak of an unusual Asian disease, which is expected to kill 600 people. Two alternative medical plans to treat the disease have been proposed. Assume that the exact scientific estimates of the consequences of the plans are as follows: - If plan C is adopted, 400 people will die. - If plan D is adopted, there is a one-third probability that none of them will die and a two-thirds probability that all the 600 people will die. which of the two programs would you favour ?

8. Introduction (7) Asian disease Plan A: 200 people will be saved. Plan B: there is a one-third probability that all 600 people will be saved and a two-thirds probability that none of them will be saved. Plan C: 400 people will die. Plan D: there is a one-third probability that none of them will die and a two-thirds probability that all the 600 people will die. 78%72% PLAN APLAN B “Die” Negative framing “Save” Positive framing Framing effect

9. Introduction (8) The Wang’s Asian disease Imagine that the U.S. is preparing for the outbreak of an unusual Asian disease, which is expected to kill 6 people. Two alternative medical plans to treat the disease have been proposed. Assume that the exact scientific estimates of the consequences of the plans are as follows: - If plan A is adopted, 2 people will be saved. - If plan B is adopted, there is a one-third probability that all 6 people will be saved and a two-thirds probability that none of them will be saved. which of the two programs would you favour ?

10. Introduction (9) The Wang’s Asian disease NO FRAMING EFFECT Plan A Plan B FRAMING EFFECT 6006

11. Introduction (10) The Wang’s Asian disease EVOLUTION ? Framing effect

12. Introduction (11) evolution and decision Social context Primary cue Decision Imagine that the U.S. is preparing for the outbreak of an unusual Asian disease, which is expected to kill 6 people. Two alternative medical plans to treat the disease have been proposed. Assume that the exact scientific estimates of the consequences of the plans are as follows: - If plan A is adopted, 2 people will be saved. - If plan B is adopted, there is a one-third probability that all 6 people will be saved and a two-thirds probability that none of them will be saved.

13. Introduction (12) evolution and decision Not a valid Social context Decision Secondary cue Imagine that the U.S. is preparing for the outbreak of an unusual Asian disease, which is expected to kill 600 people. Two alternative medical plans to treat the disease have been proposed. Assume that the exact scientific estimates of the consequences of the plans are as follows: - If plan A is adopted, 200 people will be saved. - If plan B is adopted, there is a one-third probability that all 600 people will be saved and a two-thirds probability that none of them will be saved.

14. Introduction (13) evolution and decision Evolution settled down a sensibility

15. Introduction (14 and last ) Our hypothesis Explore the social context variable. –Modifying the nature of the group at stake –Modifying the size of the group at stake –Modifying the genetic link between the decider and the group at stake Explore the reason of the framing effect. –Modifying the group size –Modifying the group species –Modifying the complexity of the problem Explore the directionality of the framing effect. –Evaluate the participant's natural tendency toward the risk. –Identify the variables that can modify this tendency.

16. Experiments (1) Experiment 1: Group Composition Effect Experiment 1b: replication of the Experiment Experiment 2: Magic #3 Experiment 3: comparison of two populations in a large group context Experiment 4: Comparison human-whales and effect of the group size Experiment 5: small group of whales Experiment 6: 5 friends and one kin Experiment 7: Genetic distance Experience 8: Older subjects Experiment 9: balanced framing Experiment 10: Direct evaluation of Minimum Requirement Experiment 11: Scaling of various scenarios Experiment 12: testing different scenarios for framing effect

17. 1 st Experiment : Comparison of large groups Group1: Imagine that the whole human population (i.e. about 6 bilion of people) is infected by an unusual Asian disease that is expected to kill all of them… Group3: Imagine that the whole whales population (i.e. about 3 millions of whales) is infected by an unusual disease that is expected to kill all of them… Group5: Imagine that a whole ET population (i.e. about 6 bilion of indiviual) is infected by an unusual disease that is expected to kill all of them… Group1: positive framing Group2: negative framing Group3: positive framing Group4: negative framing Group5: positive framing Group6: negative framing

18. 1 st Experiment : results Framing effect Framing effect Framing effect

19. Hypothesis: People Whales 2 nd Experiment : Comparison human-whales and effect of the group size Group1: Imagine that 6 people are infected by a deadly Asian disease… Group3: Imagine that 6 whales are infected by a deadly Asian disease… Framing effect

20. 2 nd Experiment : results Framing effect Framing effect

21. Discussion (1) Sensitivity to the social context ? HumanWhales Extra- terrestrial Small grouplarge group large group Small group large group Framing effect mixedhomogeneous kinstranger No Yes/NoYes No

22. Discussion (2) Evolutionary mechanism ? cross-cultural presence of the effect persistence of the effects within the lifespan Strength/replicability of the effects effect of the genetic link between deciders and potential victims gender differences

23. Conclusions Professional decider should be aware of these kind of sensitivity Evolutionary psychology should be extended to the study of other behavior Free will ?