An Exploration of Decision An Exploration of Decision Processes in an Processes in an

Evolutionary Perspective:Evolutionary Perspective:

the Case of the Framing Effect

Neo-Darwinism

Cognitivepsychology

Introduction (1)Evolutionary psychology

Evolutionary Psychology

Introduction (2) Evolutionary psychology

Evolution

EvolutionEvolution tooNon-human cognition High level cognition

Introduction (3)Decision making

“Making decision is like speaking prose - people do it all the time, knowingly or

unknowingly”

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 ?

– 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

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 ?

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 A PLAN B

“Die”Negative framing

“Save”Positive framing

Framing effect

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 ?

Introduction (9)The Wang’s Asian disease

0

20

40

60

80

100

positive framing negative framing

NO FRAMING EFFECT

Plan APlan B

0

20

40

60

80

100

positive framing negative framing

FRAMING EFFECT

600 6

Introduction (10)The Wang’s Asian disease

EVOLUTION ?

Framing effect Framing effect

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.

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.

Introduction (13)evolution and decision

Evolution settled down a<social context> sensibility

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.

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

1st 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

1st Experiment : results

0

50

100

Human

s +

Human

s - -

Whal

es +

Whal

es - -

ET +ET - -

Plan B

Plan AFraming

effect

Framingeffect

Framingeffect

Hypothesis:

People

Whales

2nd 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

Framing effect

2nd Experiment : results

0

50

100

Whales+

Whales -

- Humans+

Humans-

-

Plan B

Plan AFraming

effectFraming

effect

Discussion (1)

Sensitivity to the social context ?

Human WhalesExtra-

terrestrial

Small group large group

large group

Small group

large group

Framing effect

mixedhomogeneous

kin stranger

No No Yes/No Yes Yes Yes No

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

Conclusions

• Professional decider should be aware of these kind of sensitivity

• Evolutionary psychology should be extended to the study of other behavior

• Free will ?