Reductionism refers to two rather different theoretical approaches: the belief that the phenomena of psychology can be explained within the framework of the basic sciences (such as physiology), and the belief that we can explain psychology in terms of simple principles, such as simple stimulus—response associations. Reductionism can be considered in terms of the basic sciences. We can see that the sciences can be organised in a hierarchy, with the more general sciences at the top and the more narrowly focused ones at the bottom. Those at the bottom progressively explain higher-level sciences.
Reductionism has several disadvantages. Many psychological phenomena cannot be reduced to physiological or biological terms. Psychology is concerned with processes, whereas physiology is concerned with structure. Reductionism can also be considered in terms of reducing complex phenomena to separate simple parts, as in behaviourism. However this approach has been shown to be lacking, for example when using behaviourist principles to explain language acquisition or the causes of mental disorders.
The eclectic approach is that psychologists should gather
significant and relevant information together from various sources and
disciplines as exemplified by explanations of schizophrenia, rather than trying
to produce a single theory (Reductionism being a single theory).
Neurology and biochemistry underlie all behaviour. What happens when a person sees a sunset? The physiological explanation would be that light reflected from the landscape forms an image on the retina, which is converted into a neural signal and transmitted to the brain, and so on. No one disputes that this is true, and the process is absolutely essential, but does it give a full and adequate explanation of what is going on? A psychological explanation would probably include the personal and social relevance of the experience, which many would argue are of equal value.
The biological approach. Reductionism is often equated with physiological reductionism, offering
explanations of behaviour in terms of physiological mechanisms. The
evolutionary approach uses evolutionary reductionism when reducing behaviour to
the effects of genes, as in some explanations of altruism or atypical
behaviour.
The behaviourist approach uses a very reductionist vocabulary:
stimulus, response, reinforcement, and punishment. These concepts alone are
used to explain all behaviour. This is called environmental reductionism
because it explains behaviour in terms of simple environmental factors.
Behaviourists reduce the concept of the mind to behavioural components, i.e., stimulus-response
links.
The cognitive approach uses
the principle of machine reductionism. Information-processing
approaches use the analogy of machine systems, and the simple components of
such machines, as a means to describe and explain behaviour. More recent
computer innovations, such as the Internet and connectionist networks can be
described as holist because the network behaves differently from the individual
parts that go to make it up. The whole appears to be greater than the sum of
its parts.
The psychoanalytic approach is reductionist in so far as it relies on a basic set of structures that attempt to simplify a very complex picture. On the other hand, Freud used idiographic techniques (e.g. case study or individual interview) that aim to preserve the richness of human experience rather than teasing out simple strands of behaviour.
The humanistic approach emerged
as a reaction against those dehumanising psychological perspectives that
attempted to reduce behaviour to a set of simple elements. Humanistic, or third
force psychologists, feel that holism is the only valid approach to the
complete understanding of mind and behaviour.
We should also include
experimental reductionism, the use of controlled laboratory studies to gain
understanding of similar behaviours in the natural environment. This approach
inevitably must reduce a complex behaviour to a simple set of variables that
offer the possibility of identifying a cause and an effect.
Michael W.Eysenck & Cara Flanagan, 2001, Psychology for A2
level, Psychology Press, ISBN 1-84169-251-4 (Highly recommended text for broad
overview of psychology, written in an easy to understand style)