Comparing Axiomatic and Ecological Theories of Rationality:

The Case for an Internalist Ecological Rationality

Patricia Rich (Carnegie Mellon University, Pittsburgh)

G.I.R.L. 2013Lund University

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Thesis

Developing a successful normative theory of individual rationality is very important. Yet

neither of the two predominant approaches – traditional axiomatic theories (TATs) and the

newer ecological rationality (ECO) – is adequate. While ECO improves on TATs, we

must go one step further, and develop an internalist version of ECO.

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Motivation

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One General Problem

What is rationality for

an individual?

What are the norms

that I ought obey?

Practical

consequences

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Some Criteria for a Theory of Individual Rationality

In order of importance: Usefulness & the “ought-can” principle A unified, top-level theory is desirable Accuracy (with respect to intuitions – more on

this later)

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A Framework for Studying Rationality

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The SCOP Formalism Given an entity of interest, a state,

context, property system describes: The state of the entity in terms

of its properties State changes under the

influence of contexts Context changes under the

influence of states

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The SCOP Formalism

Developed by Diederik Aerts (and collaborators) in past few decades

Originally a tool for quantum mechanics, but found to have broader applications, as it captures a very general structure

For example, Aerts uses it to explain empirical data on concept combination and opinion formation in humans

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A SCOP Reasoning System

Aerts says SCOP is abstract enough

that the entity represented can be

nearly anything: a particle, a cat, a

mind. So:

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A SCOP Reasoning System

Let the entity be an agent's mind With its mental states represented by

mental properties The system undergoes change as the

mind interacts with the environment

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At every time point, the mind can be described by a mental state.

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The mind has a set of properties attached to it at all times.

A mental state is characterized by the subset of properties that are active at that time.

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At every time point, the mind is also faced with some external context.

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Transitions from one state-context pair to another are probabilistic.

Probabilities may be non-classical; given as interval subsets of [0,1].

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SCOP is useful for studying rationality because...

It allows us to holistically represent everything

that could fall under the domain of rationality

for an individual:

– Implicit and explicit reasoning

– Small-scale and large-scale activities

– Internal and external facts

– Decisions, inferences, belief revisions, etc.

– Overall performance and instances

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SCOP is useful for studying rationality because...

This makes it hard to beg questions, e.g.

regarding the scope of rationality or its

domains.

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SCOP is useful for studying rationality because...

It seems to offer an accurate general

representation of our mental activities, and

there's good evidence (from Aerts) that it can

model the specifics, too. This will be helpful when we want to combine

normative and descriptive work to evaluate

actual activity.

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A Particular Problem

Two rival theories: The Traditional Axiomatic Approach:

Rationality consists in obedience to general principles, traditionally given as sets of axioms

Ecological Rationality: Rationality consists in tailoring our choice and

inference behavior to the particular context, as evolution has shaped us to do

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Let's use SCOP to define and investigate these theories in more detail.

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The Traditional Axiomatic Approach

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The Traditional Axiomatic Approach

The TAA says that rationality consists in obeying general rules (axioms) relevant

to your task.

So the first question is: what domain are you in?

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The domain picks out a set of contexts that share a common task (decision, inference, etc.).

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The task constitutes an experiment, or a particular context. A TAT asks whether a particular response to the task is rational.

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The relevant response to the given task is the outcome of the experiment.

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A rationality judgment is pronounced by checking whether the outcome obeys the axioms triggered by the context-group (domain) given the additional context-information from the experiment.

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Ecological Rationality

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ECO says that rationality is a question of the “match” between the particular context and a particular process for

completing the context's task.

So the first question is: which process and which context?

I take the Adaptive Behavior and Cognition (ABC) group of the Max Planck Institute

to be the authority on this theory.

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Ecological Rationality

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Ecological Rationality

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Ecological Rationality

As with TATs, outcomes are defined out from new contexts as appropriate. Here, the expected outcome is calculated.

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Ecological Rationality

ECO says: process is rational to the extent that its expected outcome is better than that of other candidate processes, and the process is fast and efficient, holding the context fixed.

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Example: The Recognition Heuristic

Process relatively rational in this context because “accurate,” “fast,” and “frugal.”

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Comparing TAT and ECO

Comparing the Theories

• Theorists often seem to talk past each other and overstate differences:– Nothing in the TATs precludes heuristic use by the

agent– It’s agreed that context matters; both approaches

need the info captured by the “experiment” – It’s agreed, also, that time, energy, etc. affect utility– The basic premise of expected utility is retained – it

justifies both axioms and processes

Primary Differences

TATs evaluate actual outcomes, while ECO evaluates potential or expected outcomes

TATs judge observed behavior, while ECO judges processes for producing behavior

So, contextual factors and components of utility are accounted for in different places

ECO also makes relative rather than absolute judgments

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ECO's Advantages

A graded concept of rationality is richer, more intuitive, and arguably more useful ECO is more explicit about the importance of context and utility components, and clarity is good For an individual seeking normative guidance, it makes more sense to evaluate implementable processes

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The Importance of Processes

Intuitively, looking at processes is an improvement in part because our rationality concept has an internalist dimension: rationality has to do with reasoning and internal consistency

ECO, however, looks at processes for a different reason

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ECO and Reliabilism

ECO, as described by ABC, is an externalist theory of rationality, and in particular reliabilist

Reliabilism means that processes are judged on whether they will in fact reliably perform well

Importantly, the agent's relationship to this fact is irrelevant (even animals can be ecologically rational)

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The Case for Internalist ECO

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When Reliabilism Fails

A process being a “good match” for the actual

environment and the perceived environment are

different questionsRationality depends on the latter

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What Kind of Internalism?

In particular, I suggest that we evaluate processes by their expected outcome relative to the context the agent takes to obtain

Apart from this, ECO is on the right track

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When Reliabilism Fails

This internalism is: Conducive to usefulness Intuitively accurate In keeping with recent (productive) trends

such as the epistemic program in game theory,

work on context influencing inferences, greater

accommodation of subjective judgments in EUT.

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When Reliabilism Fails

The value of internalism manifests itself

especially in strategic situations, when agents

are most likely to be wrong about external facts

influencing their outcomes, but still justified, and

arguably rational, in their choices

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Example: A Poker Game

Fred, a poker novice, sits down to a game with his friends. The context is a friendly-but-competitive game of Omaha. Fred, however, thinks that they are not really playing competitively, and so his friends would not bluff him. He folds even very strong hands whenever someone makes a large bet, thinking he is beaten.

Fred is rational, but ECO will not discover this.

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Conclusions and Future Work

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Summary

By looking at a more complete representation of human reasoning (as a SCOP), we were able to better understand the natures of TATs and ECO.I argue that ECO makes several much-needed

improvements on TATs, but in its turn towards reliabilism and away from internalism, it goes in

the wrong direction.

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Rationality

An internalist ECO would say that:An agent's use of a process is rational to the

extent that it has high expected performance, by the agent's own standards, given the context the agent takes to obtain.

An agent may be at fault for errors regarding context, but importantly, the process responsible for the errors, and not the process resulting from them, is to be criticized.

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Is this a useful theory?

Recall: a useful theory provides implementable norms.

Here, norms should specify features a process should have given the features of the context.

Recall that ECO compares processes. So the agent need not solve for the best

process; the theory just says that improvements move from processes with fewer desirable features to more.

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Thank you!

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A SCOP System

S an entity A SCOP system is a tuple (Σ, M, L, μ, ξ) Σ the set of states s of the entity L the set of properties attached to S M the set of contexts S can be faced with

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A SCOP System

A SCOP system is a tuple (Σ, M, L, μ, ξ) μ:M X Σ X M X Σ → P([0,1]) a transition function saying (probabilistically) which new state- context pairs may arise from an old one ξ:Σ → P(L) such that ξ(s)= L_s

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Can Animals Be Rational?

It would be reasonable to require that rationality judgments only be applied to agents with certain capacities or features:

Self-consciousness, beliefs, etc. The ability to apply such judgments to one's self

and make changes (a kind of learning) Once this requirement is met, agents and even

their unconscious activities can be rational, because in principle the agent could reflect and make a change

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According to the traditional axiomatic approach:

Rational decisions are those obeying the axioms of expected utility theory (EUT)

Rational inferences obey the axioms of (classical) logic

A rational revision of one's beliefs obeys axioms of belief revision (AGM)

Etc.