Holism and reductionism: levels of explanation in psychology. Biological reductionism and environmental (stimulus-response) reductionism.
Where do the main approaches in psychology stand on reductionism?
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. Wundt’s early work in the areas of perception and thinking was reductionist, in its attempt to reduce human thought to elementary sensations. In the same way that the chemical elements such as hydrogen and oxygen combine to form complex compounds, the same might be true for sensations and mental processes. The whole appears to be greater than the sum of its parts.
The evolutionary approach derives from Darwin’s theory of evolution. Darwin himself didn’t know anything about genes, but it emerged after his death that genetic inheritance is of key importance in natural selection. Advocates of this approach argue that we can understand much of human behaviour and differences among species by focusing on evolutionary history.
The psychoanalytic approach is reductionist insofar as it relies on a basic set of structures that attempt to simplify a very complex picture. On the other hand, and to complicate things a little (!), Freud used idiographic (i.e., individually based) techniques that aimed 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.