theoretical issues in psychology
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Theoretical Issues in Psychology. Philosophy of Science and Philosophy of Mind for Psychologists. Chapter 2 Kinds of explanations. 3 kinds of explanations Reduction Levels of explanation Reasons and causes Explanatory pluralism. Explanation. - PowerPoint PPT PresentationTRANSCRIPT
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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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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.