Reductionism and holism

• What is holism?

  An argument or theory which proposes that it only makes sense to study an indivisible system rather than its constituent parts.
• What is reductionism?

  Breaking down behaviour into constituent parts. Reductionist approaches analyse behaviour by breaking it down into smaller units. This is based on the scientific principle of parsimony - all phenomena should be explained using the most basic, lowest level and simplest principles.
• The notion of levels of explanation suggests there are different ways of viewing the same phenomena in psychology - some are more reductionist than others.
• For example, OCD may be understood in different ways:

  • Socio-cultural level - it involves behaviour most people would regard as odd (eg. repetitive hand-washing).
  • Psychological level - the individual's experience of having obsessive thoughts.
  • Physical level - the sequence of movements involved in washing one's hands.
  • Physiological level - hypersensitivity of the basal ganglia.
  • Neurochemical level - underproduction of serotonin.
• Psychology can be replaced by a hierarchy of reductionism:


  Psychology can be placed in a hierarchy of science, with the more precise and 'micro' of these at the bottom (eg. physics), and the more general and 'macro' at the top (eg. sociology). Researchers who favour reductionist accounts of behaviour see psychology as ultimately being replaced by explanations derived from those sciences lower down in the hierarchy.
• Biological reductionism:


  Physiological and neurochemical level. We are biological organisms made up of physiological structures and processes - all behaviour is at some level biological and can be explained through neurochemical, neurophysiological, evolutionary and genetic influences. This assumption has been successfully applied to the explanation and treatment of mental illness.
• Environmental reductionism:

  Physical level, behaviourist stimulus-response links. The behaviourist approach is built on environmental reductionism - behaviourists study observable behaviour and break complex learning up into simple stimulus-response links. So the key unit of analysis occurs at the physical level - the behaviourist approach is not concerned with cognitive processes at the psychological level.
• AO3 - Holism can explain key aspects of social behaviour:


  There are some social behaviours that only emerge within a group context and cannot be understood at the level of individual group members. For example, the effects of de-individuation of prisoners and guards in the Stanford prison experiment could not be understood by studying the participants as individuals - it was the interactions between the people that mattered. This shows that holistic explanations are needed for a more complete understanding of behaviour than reductionist approaches.
• AO3 - Holism is impractical:

  Holistic explanations tend not to lend themselves to rigorous scientific testing and become vague and speculative as they become more complex. For example, if we accept there are many factors contributing to depression, it is difficult to establish which is most influential and which to use as a basis for therapy. This suggests that when it comes to finding solutions for real world problems lower level explanations may be more applicable.
• AO3 - Reductionism has scientific credibility:

  A reductionist approach often forms the basis of scientific research. Target behaviours are reduced to constituent parts to create operationalised variables. This makes it possible to conduct experiments or record observations (behavioural categories) in meaningful and reliable ways. This gives psychology greater credibility, placing it on equal terms with the natural sciences lower down in the reductionist hierarchy.
• AO3 - Reductionist approaches lack validity:


  Reductionist explanations at the level of genes or neurotransmitters oversimplify complex phenomena and so lose validity. They fail to analyse the social context of behaviour - but this is where the behaviour derives its meaning. Physiological processes in pointing one's finger are the same in any context. But an analysis of these processes does not tell us why the finger is pointed (eg. as an aggressive act). This means that reductionist explanations can only ever form part of an explanation.