Biological Reductionism & Drug Treatments (DP IB Psychology): Revision Note

Biological reductionism & drug treatments

• The holism–reductionism debate concerns whether behaviour is best explained by:

  • Reductionism – breaking behaviour down into its simplest parts

  • Holism – considering multiple interacting factors together

Reductionism

• A reductionist approach involves a simplistic, ‘reduced’ explanation for a complex behaviour

  • Biological reductionism - crime is in your genes

  • Environmental reductionism - growing up in a certain area makes you criminal

• Biological reductionist explanations are based on the idea that biological functions and structures can explain behaviour

  • The monoamine hypothesis of MDD assumes that abnormal serotonin levels cause depression

  • Drug therapies (e.g., SSRIs, NRT) assume that behaviour results from neurochemical imbalances

  • Genetic explanations of MDD assume depression is highly heritable, ignoring environmental influences

Holism

• Considers biological, psychological, and social factors together

  • E.g., crime is the result of multiple interacting causes, so to understand crime, we must also understand the criminal

• The holism-reductionism debate refers to the difference between explaining behaviour via:

  • fundamental constituent parts (reductionism)

  • considering all aspects of the individual (holism)

Evaluation of biological reductionism & drug therapy

Strengths

• Taking a biologically reductionist approach to explaining behaviour brings scientific clarity

  • Reductionism isolates variables (e.g., dopamine and addiction), making it easier to design studies and test hypotheses

• Reductionist explanations have led to practical applications as our understanding and treatment of disorders (such as MDD) has improved

  • E.g., the 5HT1-D gene in serotonin transport has led to to effective drug therapies such as SSRIs

Limitations

• Reductionist explanations have led to oversimplification

  • Human behaviour is complex, and reducing it to one factor (e.g., a single gene or neurotransmitter) neglects lived experiences such as stress, trauma, or social support

• Drug therapies may reduce symptoms (e.g., SSRIs block serotonin reuptake), but it remains unclear why this works or whether improvements are partly due to the placebo effect

Link to concepts

Perspective

• Levels of explanation are part of reductionism in that they seek to establish a hierarchy as to whether psychology is a science according to specific criteria and methods used to investigate behaviours

• Psychology as a discipline cannot adhere to the laws of other, 'hard' sciences (e.g. ,physics) so it applies levels of explanation to explain phenomena

• Kuhn (1990) coined the phrase 'pre-science' to define psychology

• Using levels of explanation means that the same behaviour/phenomenon can be viewed and explained in a variety of different ways

  • Biological reductionism is considered the lowest level of explanation, whereas holism is the highest

Change

• A paradigm is a set of shared assumptions and methods within a particular discipline; e.g., the biological approach argues that depression is the result of a neurochemical imbalance

• A paradigm shift occurs when a field of study moves forward through a scientific revolution

  • E.g., the discovery that the earth is not flat, but round

• These new ideas gain traction as scientists begin to challenge the old theory, adding more research to contradict existing assumptions

• A crucial point occurs at which the old paradigm is discarded for the new paradigm

  • This is true for the treatment of MDD with drug therapy, as the biological approach moved to the forefront of research in the 1980s with the development of more sophisticated technology, culminating in cognitive neuroscience today.