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ISSUES DEBATES IN PSYCHOLOGY

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					ISSUES & DEBATES IN PSYCHOLOGY

Topics to Consider
• Overview • why do people adopt particular positions? • Reductionism and its appropriateness • forms of reductionism • a hierarchy of explanation • Free will and determinism • either/or, or somewhere in-between? • Heredity and environment

• how do they interact in shaping behaviour?

Overview
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Disagreement about a range of issues Views on these issues affect the purpose and methods of psychology Different positions lead to different approaches to psychology Important to understand these issues to be able to evaluate theories in psychology

Why Adopt a Position?
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• • •
There are no objective criteria to resolve issues in psychology
An individual’s viewpoint on particular issues is shaped by a number of factors These include socio-cultural context, political beliefs, the background of the theorist, and sources of funding Understanding the basis for a particular position helps us to assess the validity of theories

Reductionism
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Reductionism is the view that complex phenomena can be best understood by reducing them to separate simpler parts Often, reductionists may claim that only one form of explanation is necessary to explain behaviour
There are various forms of reductionism

Reductionism often relates to levels of explanation

Types of Reductionism
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There are at least four types of reductionism:
physiological reductionism biological reductionism experimental reductionism machine reductionism We’ll look at each in turn We’ll then see how reductionism relates to levels of explanation

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Physiological Reductionism
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Psychological explanations are replaced by physiological explanations
In terms of brain operation, genetics, or both (‘neurogenetic determinism’) Amenable to scientific explanation, provides simple explanations

• •

Successful, e.g. in treatments for schizophrenia
Doesn’t explain everything, e.g. what’s the ultimate cause of schizophrenia?

Biological Reductionism
• • • •
Explain human behaviour in terms of simpler animals, e.g. comparative psychology, behaviourism, sociobiology Use simpler animals to find genes for behaviour
Assumes continuity of behaviour, and shared behavioural repertoire

However, if humans are physiologically different from other animals, might they also be behaviourally different?

Experimental Reductionism
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• • •
An issue of method rather than philosophy Suggests that the right way to investigate behaviour is to isolate particular factors influencing behaviour Behaviour can then be explained solely in terms of those factors E.g. experiments on the effect of noise on short-term memory May lead to a loss of external validity But need internal validity to produce precise scientific theories

Machine Reductionism
• • • • •
Again, an issue of method
Refers to the use of computer models to explain behaviour

Based on the metaphor of ‘mind as computer’
Has produced some impressive simulations But is the mind really like a computer?

Reductionism & Levels of Explanation
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Can also think about reductionism in terms of a hierarchy of levels of explanation, corresponding to different sciences Sciences lower down the hierarchy are more scientific than those above Reductionism can be seen as an attempt to use a lower level of explanation - e.g., explaining personality in terms of genetics – in order to be more scientific Watson: ‘There is only one science, physics: the rest is just social work.’

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A Hierarchy of Sciences
Science Sociology Social psychology Cognitive psychology Units of explanation Society Groups Mental processes

Example: shaking hands Political role, e.g. Adams & Trimble
Social purpose: affiliation Instructions to hand Action of muscles and nerve fibres Genetic basis of affiliative behaviour Role of chemicals in affecting behaviour

Physiology of systems
Physiology of units Anatomy/biochemistry Chemistry Physics

Brain physiology
Genes Chemicals in situ, e.g. the brain Chemicals in isolation Subatomic particles

Different Kinds of Question
•
• • • •
Looking at reductionism in this way, it’s tempting to ask ‘what’s the right level?’
There’s no one right level - it depends what you want to know Psychology asks ‘why’ questions and ‘how’ questions In asking ‘why do we shake hands?’, a social psychological or genetic level might be appropriate In asking ‘how do we shake hands?’ a cognitive or physiological level might be preferred

Evaluation
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Advantages of reductionism: • scientific • concise explanations • some successful interventions Disadvantages of reductionism: • may lose features of the phenomenon of interest (‘can’t see the wood for the trees’) • often used to provide neurogenetic explanations, but most behaviours - e.g., violence - have a social meaning that may not correspond to biological processes • reductionist explanations may be used for a particular purpose, by those who are biased

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Free Will and Determinism
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Do we have free will, or is all our behaviour determined by identifiable causes? Much of psychology assumes determinism, since to be scientific (finding cause and effect) means identifying determining causes However, determinism conflicts with our subjective experience of choice

Definitions of Free Will
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Choice: • people have free will if they have a genuine choice of behaviour • untestable - we may not be able to detect existing causes Behaviour that is unconstrained: • behaviour is often predictable, so we can’t say behaviour is random - there are usually causes • seeing behaviour as unconstrained means these causes don’t have to be adhered to Voluntary behaviour: • behaviour over which we have control

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Defining Determinism
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Comes in a range of forms, depending on what’s seen as determining behaviour
e.g. behaviourism, psychodynamics, evolutionary psychology Determinism means all behaviour has theoretically identifiable causes, and in the extreme that all future behaviour is predictable Fits classical science, though modern physics disputes hard determinism

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• •

Soft Determinism
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•
A compromise position
Behaviour is seen as determined to an extent, but in the absence of compulsion people have a degree of choice There is ultimately a causal explanation, but we may not have access to it, so it’s irrelevant

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•

The question then becomes ‘How much is determined?’
Different scientific approaches disagree about how much is determined

Evaluation
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• • •
Belief in free will matches subjective experience, but not scientific
Can accept our everyday sense of moral responsibility - that people choose to behave in certain ways However, difficult to find an explanation of behaviour if we don’t accept determinism Likely that different phenomena differ in the extent to which they’re determined

•

e.g. language use vs. instinctive responses

Heredity and Environment
• • •
What are the relative influences of heredity and environment on behaviour? An ongoing and controversial debate in psychology Is discussed today in terms of the influence of genetic inheritance, but the debate predates the discovery of genes

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In psychology, mainly focused on explaining personality and intelligence

The Viewpoints
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Environment: • newborn children are a blank slate • behaviour, character, capabilities are shaped by the environment • allows the possibility of change - change the environment, change the individual Heredity: • newborn children carry a genetic blueprint • genetic inheritance shapes character • abilities develop over time as a result of biological maturation • sees abilities as fixed, but changeable through eugenics

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How do they Relate?
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• • •
Initially seen as an either/or question: which shapes the individual?
Actually both have a role (e.g. the inheritance of height), so question changed to how much of an effect each had Based on the notion that heredity and environment have separable effects Actually, an interaction between the two: genes are expressed in an environment

Interaction of Heredity and Environment
• • • •
How do we get from the genetic blueprint (the genotype) to the finished adult (the phenotype)? Genotype contains more genes than needed - some active only under certain conditions or are recessive Less than 50% of genotype contributes to phenotype Introduces flexibility to development, but makes final phenotype hard to predict

Looking at the Environment
• •
• •
The environment covers a broad range of factors, from conditions in the womb to the social environment Organic factors are those that lead to physiological change, e.g. disease, nutrition
Stimulative factors make up the social context, e.g. type of schooling, social class Broad factors leave long lasting effects, narrow factors have short-term effects

Looking at the Genotype
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•
A wide range of characteristics are represented in the genotype However, these vary in how direct an effect they have on the phenotype • very direct: inherited syndromes, such as Huntingdon’s chorea • less direct: susceptibility expressed in the right environment, for example schizophrenia • very indirect: more influenced by environment, e.g. gender differences in technical skills? 70 trillion possible genotypes, infinite number of environments, hence considerable diversity

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Heredity-Environment Interaction

Genotypes and Psychology
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Preceding discussion certainly true for physiology More complicated for psychological characteristics Difficult to correlate psychological characteristics with genetic make up, because mediated by brain Brain has properties of self-organisation and plasticity, making it very flexible Considerable changes in the brain over development • adult brain has half the brain cells of a newborn Phenotype necessarily different to phenotype, degree of difference varies for different parts of brain

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