Biological approach

• What are the main assumptions of the biological approach?


  • All thoughts, feelings, and behaviours have a physical, genetic basis
  • Behavioural characteristics are inherited through genes
  • Studies the brain and genes
  • Many aspects of behaviour can be explained via localised areas of brain
  • Damage to parts of brain = characteristic and behaviour changes
  • To fully understand behaviour, must look at biological structures - genes, neurochemistry, nervous system
• What studies are used to test the biological approach?

  Twin studies, adoption studies, and family studies.
• What are monozygotic twins vs. dizygotic twins?


  Monozygotic: identical twins from one fertilised egg - share 100% of genes. Dizygotic: fraternal twins from two separate eggs fertilised by two different sperm - share 50% of DNA/genes
• What is a concordance rate?


  The statistic indicating the likelihood that both twins will display the same characteristic
• What is a genotype vs. a phenotype?


  Genotype: Genetic makeup of an organism. Phenotype: Observable physical manifestation of the genetic makeup of an organism.
• Why are twin studies conducted for the biological approach?


  If monozygotic twins have a higher concordance rates than zygotic twins for behaviours, it proves the behaviour has a genetic biological basis.
• What is PKU?


  A rare genetic disorder detected in birth and if unchecked, it can lead to severe learning difficulties.

  Diet can help prevent/keep it in check
• What are the strengths of the biological approach?


  • Good use of scientific methods - fMRI, family and twin studies
  • Will become more accurate as technology develops
  • Mental illness can be explained - removes blame from the individual, probably increasing self-esteem
  • Real-life applications - development of psychoactive drugs to prevent disorders e.g. PKU and depression
• What are the weaknesses of the biological approach?


  • Very determinist - assume behaviour is caused by internal, biological processes, removing independence and accountability
  • Might associate disorders occur due to a lack of the drug - creating a reliance of the solution (the drugs)
  • Difficult to separate nature and nurture - twins typically grow up together so differentiation is hard (can be solved via twins separated at birth)
• What was Darwin's proposal?


  Natural selection - genetically-determined behaviour enhancing survival will be passed on to future generations and poor traits are removed from the gene pool over time