GI<;@:K89CP
@II8K@FE8C
The Hidden Forces That Shape Our Decisions
;8E8I@<CP
REALITY
VS.
SUBJECTIVE REALITY
D. Purves
Reality???
D. Purves
D. Purves
ILLUSIONS AS A METAPHOR
A FEW EXAMPLES OF
“DECISION ILLUSIONS”
Johnson & Goldstein (2003)
s
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% of drivers donating organs
Organ donations?
100
80
60
100
40
28
4
17
98
100
100
100
100
86
12
Opt-in
Check the box below if you want to
participate in the organ donor program
Opt-in
n
i
o
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t
’
n
d do
pe
n
a
- want to
Check the box belowboifxyou
e
h
t
cks organ donor program
participatech
inethe
t
’
n
o
d
e
opl
Opt-in
n
i
o
j
t
’
n
d do
n
a
- want to
Check the box belowboifxyou
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h
t
cks organ donor program
participatech
inethe
t
’
n
o
d
e
opl
pe
Opt-out
Check the box below if you don’t want
to participate in the organ donor program
Opt-in
n
i
o
j
t
’
n
d do
n
a
- want to
Check the box belowboifxyou
e
h
t
cks organ donor program
participatech
inethe
t
’
n
o
d
e
opl
pe
Opt-out
n
i
o
j
nd
a
Check the box belowthife you
box don’t want
s
k
c
e
h the organ donor program
to participate
in
c
t
’
n
o
d
e
l
p
peo
Opt-in
n
i
o
j
t
’
n
d do
n
a
- want to
Check the box belowboifxyou
e
h
t
cks organ donor program
participatech
inethe
t
’
n
o
d
e
opl
pe
Opt-out
n
i
o
j
nd
a
Check the box belowthife you
box don’t want
s
k
c
e
h the organ donor program
to participate
in
c
t
’
n
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l
p
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What about professionals?
Redelmeier & Shafir (1995)
What about professionals?
Redelmeier & Shafir (1995)
What about professionals?
?
Redelmeier & Shafir (1995)
What about professionals?
?
Redelmeier & Shafir (1995)
What about professionals?
?
Redelmeier & Shafir (1995)
What about professionals?
?
Redelmeier & Shafir (1995)
?
What about professionals?
?
Redelmeier & Shafir (1995)
?
The Jam study
Iyengar & Lepper (2000)
The Jam study
6 jams
24 jams
Approach
40%
60%
Try
1.4
1.5
Buy
30%
3%
Iyengar & Lepper (2000)
The Jam study
6 jams
24 jams
Approach
40%
60%
Try
1.4
1.5
Buy
30%
3%
Iyengar & Lepper (2000)
The Jam study
6 jams
24 jams
Approach
40%
60%
Try
1.4
1.5
Buy
30%
3%
Iyengar & Lepper (2000)
The Jam study
6 jams
24 jams
Approach
40%
60%
Try
1.4
1.5
Buy
30%
3%
Iyengar & Lepper (2000)
The Jam study
6 jams
24 jams
Approach
40%
60%
Try
1.4
1.5
Buy
30%
3%
Iyengar & Lepper (2000)
The Jam study
6 jams
24 jams
Approach
40%
60%
Try
1.4
1.5
Buy
30%
3%
Iyengar & Lepper (2000)
Standard Economics ...
What a piece of work is a man! how noble in reason!
how infinite in faculty! in form and moving how
express and admirable! in action how like an angel!
in apprehension how like a god!
Will Shakespeare (Act II,scene 2, of Hamlet)
Behavioral
Standard Economics ...
What a piece of work is a man! how noble in reason!
how infinite in faculty! in form and moving how
express and admirable! in action how like an angel!
in apprehension how like a god!
Will Shakespeare (Act II,scene 2, of Hamlet)
IT IS ALL ABOUT .....
IT IS ALL ABOUT .....
FREE LUNCHES !!!
people don’t know
Their preferences
measurement
Choice construction
Answer the following:
Answer the following:
Please write 3 reasons Please write 10 reasons
why you love your
why you love your
significant other
significant other
Please write 3 reasons Please write 10 reasons
to buy a BMW
to buy a BMW
Answer the following:
Please write 3 reasons Please write 10 reasons
why you love your
why you love your
significant other
significant other
Please write 3 reasons Please write 10 reasons
to buy a BMW
to buy a BMW
Answer the following:
Answer the following:
Indicate on the following scale how many times do
you floss a day:
0
1
2
3
4
5
6
7
8
9 >9
Answer the following:
Indicate on the following scale how many times do
you floss a day:
0
1
2
3
4
5
6
7
8
9 >9
Indicate on the following scale how many times do
you floss a month:
0
1
2
3
4
5
6
7
8
9 >9
Answer the following:
Indicate on the following scale how many times do
you floss a day:
0
1
2
3
4
5
6
7
8
9 >9
Indicate on the following scale how many times do
you floss a month:
0
1
2
3
4
5
6
7
8
9 >9
Should you call the dentist to make an appointment?
Answer the following:
Indicate on the following scale how many times do
you floss a day:
0
1
2
3
4
5
6
7
8
9 >9
Indicate on the following scale how many times do
you floss a month:
0
1
2
3
4
5
6
7
8
9 >9
Should you call the dentist to make an appointment?
Answer the following:
Indicate on the following scale how many times do
you floss a day:
0
1
2
3
4
5
6
7
8
9 >9
Indicate on the following scale how many times do
you floss a month:
0
1
2
3
4
5
6
7
8
9 >9
Should you call the dentist to make an appointment?
What do people infer
0
1
2
3
4
5
6
7
8
9 >9
“I am below the norm”
“I am above the norm”
0
1
2
3
4
5
6
7
8
9 >9
people don’t know
Their preferences
measurement
Choice construction
Attribute 1
Asymmetric dominance
Attribute 2
Attribute 1
Asymmetric dominance
A
Attribute 2
Attribute 1
Asymmetric dominance
A
B
Attribute 2
Attribute 1
Asymmetric dominance
A
A’
B
Attribute 2
Attribute 1
Asymmetric dominance
A
A’
B
Attribute 2
Attribute 1
Asymmetric dominance
A
B
B’
Attribute 2
Attribute 1
Asymmetric dominance
A
B
B’
Attribute 2
16%
0%
84%
16%
0%
84%
16%
68%
0%
84%
32%
Form A
Tom
Form A
Tom
Jerry
Form A
Tom
Jerry’
Jerry
Jerry’
Jerry
Form A
Tom
Form B
Tom
Jerry
Jerry’
Jerry
Form A
Tom
Form B
Tom
Tom’
Jerry
Jerry’
Form B
Form A
Tom
Tom’
♥
Tom
♥ ♥
♥
♥
♥ ♥♥
♥
Jerry
♥ ♥
♥
♥
♥ ♥♥
Jerry
Lessons
Tom
Jerry’
Tom’
♥
Tom
♥ ♥
♥
♥
♥ ♥♥
♥
Jerry
♥ ♥
♥
♥
♥ ♥♥
Jerry
VS.
VS.
@II8K@FE8C
GI<;@:K89CP
www.predictablyirrational.com
The Hidden Forces That Shape Our Decisions
;8E8I@<CP
dan@predictablyirrational.com