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Theoretical Issues in Psychology

Philosophy of Scienceand

Philosophy of Mindfor

Psychologists

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• 3 kinds of explanations• Reduction• Levels of explanation• Reasons and causes• Explanatory pluralism

Chapter 2 Kinds of explanations

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Explanation

Explanation is answering to a ‘why’ question. Three kinds of explanations:

1) Nomological explanation (D-N model) answers ‘why’ by subsumption under a general law (‘covering law’):

• sciences.2) Hermeneutic understanding (‘Verstehen’) answers ‘why’ by reconstructing context, explicating meaning and experience:

• humanities.3) Functional explanation answers ‘why’ by finding the function (‘what is it for’); mechanistic explanation:

• biology (engineering); biological psychology.

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Nomological explanation

law 1…………law n

condition 1… condition n

event (fact)

explanans

explanandum

• Subsuming an event (fact) under a general law.• Or deducing an explanandum from an explanans.• Prediction logically equals explanation.

Problem: doesn’t work for motives, reasons and actions.

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Nomological explanation

Example:

L1: Frustration causes aggressionL2: Football supporters whose club lost are frustratedC1: These supporters’ football club lost----------------------------------------------------------E: These football supporters are aggressive

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Hermeneutic understanding

• Understanding and explicating human behavior and texts.

• Describing meaningful relations in context.• Interpreting individual cases (no laws).• Motives and reasons (not causes).• Actions (not movements).• Hermeneutic circle of whole and parts.

Problem: no objectivity, not verifiable or falsifiable

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Explaining

• Natural sc.• Time-spatial events• Causes• Nomothetical• Object / objectivism• Method-oriented• Generalising over objective factsExperimental, biological psychology

Understanding

• Social sc./humanities• Actions• Reasons (motives)• Idiographical• Subject / subjectivism• Meaning-oriented• Unique events • Persons experience Client-centered therapy, psychoanalysis

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Reasons and causes in social science

• Explaining or understanding behavior?

• Action (rational, goal-directed, meaningful,motivated).

Or

• Movement (mechanical, causal, determined).

• Solution: multiple levels of explanation, understanding and causal explanation can coexist.

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Functional explanations

• What an item does, what goal it serves; not what it is (made of).

• Teleology (goal-directedness).• The presence of a trait is explained by its function,

e.g., mammals have a heart to pump blood.

• Characteristic for biology: adaptive functions selected in evolution.

• Evolutionary psychology: function of jealousy, cheater detection, etc. (see Ch. 9.2).

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Functional explanations

• The presence of a trait is explained by its function.

• Adaptation (not physical causation, not interpretation of meaning).• How system works, its design and functioning (no laws, no causes, no predictions).

Problem: danger of cheap, circular, pseudo-explanation (adaptationism).

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Mechanistic explanation

• Extension of functional explanation.• A phenomenon is explained by the orchestrated functioning of the component parts of a mechanism.• E.g., heart (mechanism) pumping blood (phenomenon) by muscles and valves (components) together.• Interlevel: lower level of components explains higher level phenomenon.

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Function

• Etiological: the trait is selected in the past

for a specific effect: evolutionary explanation. • Causal role: the contribution a trait makes

to the capacity of the whole system: systemic, engineering explanation.

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Functionalism

Is a materialistic notion of mind

Behaviorism:no mental terms and

things; only observables.

Mind-brain Identity theory:mind is brain; mental

terms have to be reducedto brain terms.

Functionalism: materialism without

reductionism.

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Functionalism

• A mental process is a functional organisation of a machine (e.g., brain), an ‘abstract’ organisation, can be realised in different kinds of hardware.

• ‘Token materialism’: every function is realised in something material.

• No ‘type materialism’: realisation in different kinds of material objects (computers, brains).

• Therefore no reduction to neurophysiology.

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Behaviorism (behavior)

Identity theory (mind=brain)

Functionalism: ‘1st cognitive Revolution’ (cognition)

‘2nd cognitive revolution’ (cognition, brain & behavior)

1913 – ca1950

ca 1950

1950 – 1985

1985 – present

Materialism in history

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Two forms of mind materialism

Type materialism of the Identity theory:

‘I’m afraid when typical brain cells are firing’

Token materialism of functionalism:‘I’m afraid when my cognitive system is in a

certain functional state’

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The type, the class: students

The tokens: student Astudent B

Type and token

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Problems of type materialism (IT) according to functionalists

• We have insufficient knowledge of brains.• Autonomy of psychology, no reduction

(identity) of psychological to neural processes.

• IT is too ‘chauvinistic’: only human brains can show intelligence; but how about a chess computer?

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Functionalism

• Mental states are functional states of physical systems.• Functions have a causal role (cause other

mental states and behavior).• Functions are materially though multiply realised.• Implementation is irrelevant for explanation.• Liberalism: computers, animals, aliens can

show intelligence.

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Criticism of biologically-orientedFunctionalists

• This is machine functionalism: function is stripped of goal-directedness and

adaptation.

• Therefore: teleological functionalism; biological functions, not abstracted from implementation or environment.

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Reduction and reductionism

Reduction: explanatory strategy

Explain complex phenomena by reducing to elements; chain of ‘why’ and ‘because’ going down from everyday macro-objects to elementary particles.

Reductionism: ideology

Reality is nothing but matter in motion (‘nothing buttery’), e.g., pain is firing of certain neurons; e.g., altruism is nothing but the blind instinct,

programmed by a selfish gene.

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Theory reduction

Theory reduction: deducing a higher level theory from more basic theories plus bridge laws (extension of D-N explanation):

e.g., deduce thermodynamics (temperature and pressure) from statistical mechanics (molecules).

Bridge laws connect theories, identifying terms (things) across theories (e.g., temperature is average kinetic energy of gas molecules):

e.g., associative learning deduced from synaptic potentiation; Long Term and Short Term Memory deduced from LTP (biochemistry); ‘neural alphabet’ (Kandel).

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Classical reduction

• DDeducing higher level science from lower level; requires connectability (bridge laws) and deducibilitysociology psychology neurofysiology physics

complex simple.

• ‘Unified science’ (positivism): same kind of observations, same kind of explanations everywhere in

science, ultimately ‘ideal physics’.

• Basic theory incorporates higher level theorye.g., Mendelian genetics subsumed under

biochemistry (DNA).

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Classical reduction

Deducing higher level science from lower level, connected by bridge laws; smooth incorporation of reduced (old) in reducing (new) theory.

Problem: Old theory usually false, concepts do not refer.New theory corrects old, meaning of concepts changes. Therefore, no bridge laws, no deduction.Classical reduction fails as account of real scientific progress works.

Then: • eliminativism: drop old theory (and its world view);• or functionalism: non-reductive materialism, autonomy.

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Non-reductive materialism

Multiple realisation: classical reduction impossible in neuro-psychology: no bridge laws (type identities) between mind and brain.

Supervenience: Mental processes determined by (dependent on) material processes. No change in mental states without change in neural process (i.e., no disembodied mind).

Compatible with functionalism as theory about the mind:• autonomy for psychology, no reduction;• but also materialism, no dualism.

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Supervenience: the mental and the neural

neural2 neural3

Neural

mental

neural1

mental

neural

no reduction determination

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Reduction vs elimination

Reduction: identification of higher level phenomenon with lower level.Retains ontology: the reduced phenomenon really exists

e.g., water is H2O; temperature is kinetic energy;e.g., pain is (identical with) firing of certain neurons.

Problem: old theory false, meaning changes: no bridge laws, no reduction.

Eliminativism: replacing higher level entities and theories by more fundamental ones.Replaces ontology: higher level entities do not really existe.g., talk of neural processes replaces ‘pain’, ‘consciousness’, ‘meaning’ etc.

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New wave reductionism, eliminativism

• Responds to failure of classical reduction: higher level eliminated.

• Old reduced theory is to some degree false, obsolete, or incomplete.

• Old reduced theory to some degree corrected or even entirely replaced by lower level reducing theory.

• Functional, psychological theories only approximate, coarse descriptions.

• Cognitive phenomena can better be explained by neuroscience.

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Reduction vs levels

• Reduction in D-N-model: unification, psychology is neuroscience.

• Eliminativism: psychology replaced by neuro-science:• these are one-level stories.

• Alternative: multiple levels of explanation:• explanatory pluralism, co-evolution of theories at

different levels.

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When classical reduction fails

1. Autonomy (functionalism), or

2. Elimination (more or less correction of the reduced theory), or

3. Explanatory pluralism (McCauley) coexisting theories, mutually influencing each other top-down and bottom-up.

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Explanatory pluralism

• Multiple levels of explanation coexist and

coevolve.

• No autonomous levels (unlike functionalism),

but mutual selection pressure.

• No reduction or elimination.