The biological approach

• What is the biological approach?

  A perspective that emphasises the importance of physical processes in the body such as genetic inheritance and neural function.
• The neurochemical basis of behaviour:

  Neurochemistry refers to the action of chemicals in the brain. An imbalance of neurotransmitters may be a cause of some mental disorders, eg. underproduction of serotonin in OCD.
• Genetic basis of behaviour:

  Twin studies are used to investigate genetic influences. Concordance rates between twins are calculated. Higher concordance rates among monozygotic twins than dizygotic twins is evidence of a genetic basis.
• What is a genotype?

  The particular set of genes that a person possesses.
• What is a phenotype?


  The characteristics of an individual determined by both genes and the environment.
• Theory of evolution explaining behaviour:

  Any genetically determined behaviour that enhances survival and reproduction will be passed on to future generations. Such genes are described as adaptive and give the possessor and their offspring advantages.
• AO3 - Real-world application:

  Understanding of neurochemical processes in the brain has led to the use of psychoactive drugs to treat serious mental disorders. For example, drugs that treat clinical depression increase levels of serotonin and reduce depressive symptoms.
• AO3 - Scientific methods:

  The biological approach makes use of a range of precise and objective methods. These include scanning techniques (eg. fMRI), which assess biological processes in ways that are not open to bias.
• AO3 - Biological determinism:

  Biological explanations see human behaviour as governed by internal, genetic causes over which we have no control. However, a phenotype is heavily influence by the environment. This suggests that the biological view is too simplistic and ignores the mediating effects of the environment.
• AO3 - Cannot separate nature and nurture:

  Identical twins, non-identical twins and members of the same family are all exposed to similar environmental conditions. This means that findings could just as easily be interpreted as supporting nurture rather than nature.