Expected utilityis always used as aheuristic

Konrad Talmont-Kaminski

Marie Curie-Sklodowska U., Poland

Line of argument

Problem with bounded rationality

Dual systems of reasoning

What is a heuristic?

Expected utility as a heuristic

H. Simon

Reason in

Human Affairs,

1983

Bounded rationality

Processes satisficing not

maximising

Methods context-dependent

Reasoning consists of heuristics

All reasoning?

Heuristics all the way up?

What about logical reasoning?

What about scientific reasoning?

Does not look like heuristics

But…

Simon’s explanation of discovery

of Boyle’s Law

J. Evans

K. Frankish

S. Sloman

K. Stanovich

D. Kahneman

& others

Dual reasoning

System 1

Heuristics

Intuitive, quick, innate, automatic

System 2

Real reasoning

Logical, slow, learned, conscious

Kahneman’s system 1

Simple heuristics

Anchoring & adjustment,

representativeness, availability

Descriptive

Focus on errors produced

Necessitated by empirical data

But Gigerenzer’s critique

Kahneman’s system 2

Logical reasoning

Utility theory, etc.

Descriptive

but also normative

Necessitated by desire to

maintain classical norms of

rationality &

Need to explain ‘system 2’

reasoning

Expected utility

Paradigmatic example

If EU functions as heuristic,

(plausibly) all reasoning does

EU does not function as

Kahneman heuristic

Need to go back to Simon’s

concept

Simon

Not necessarily

Not necessarily

Not necessarily

Not necessarily

Kahneman

Intuitive

Innate

Quick

Automatic

Simon’s heuristics

Very broad category

Kahneman examples

Behavioural adaptations

Scientific reasoning

In danger of becoming

vacuous

Only useful if it supports

substantive generalisations

Bill Wimsatt

Reengineering

Philosophy for

Limited

Beings, 2007

Common traits of heuristics

1. Fallible

2. Efficient

3. Systematically biased

4. Problem-transforming

5. Purpose relative

6. Descended from other

heuristics

EU as heuristic?

EU formalism does not look like a

heuristic

But how is EU applied in real

situations?

Using simplifying assumptions

Need to consider

formalism+assumption

Traits of EU+assumptions

1. Fallible

2. Efficient

3. Systematically biased

4. Problem-transforming

5. Purpose relative

6. Descended from other

heuristics

?

?

Heuristics all the way up

EU functions as a heuristic

Maximising formalism situated in

satisficing methodology

Same phenomenon in other

cases?

Kahneman’s ‘system 2’ not

descriptive

Probably not primitively

normative, either

H. Mercier

D. Sperber

Why do

Humans

Reason,

BBS

forthcoming

Conclusions

It is heuristics all the way up

Kahneman’s conception of

heuristics very limited

Simon’s conception much

broader and more useful

Need to go back to Simon

Thank you

Konrad Talmont-Kaminski

In a Mirror, Darkly: How the

Supernatural Reflects

Rationality (forthcoming)

konrad@talmont.com

deisidaimon.wordpress.com