Biological approach

• Assumptions


  • everything psychological has a biological basis.

  • our biology is determined by evolution & genetics.

  • investigate the mind, we must investigate the physical brain.
• What does the biological approach state

  Everything is at first biological, to study human behaviour we must first observe biological structures,
• Physical basis


  the mind lives in the brain meaning all thoughts, feelings and behaviour has a physical basis, different to the cognitive approach that sees the mind as separate to the brain
• Genetic basis


  Behaviour geneticists study whether behavioural characteristics (intelligence, personality) is inherited the same way as physical characteristics.
• Genetic basis of behaviour - Alleles DELETE


  • different forms of the same gene in different people alleles.

  • contribute to each persons unique features.
• Genotype


  refers to the genes an organism has inherited. (eye colour)
• Phenotype


  refers to the way genes are expressed through physical behaviour and psychological characteristics (shyness)

  
• twin studies


  Used to determine the extent to which some characteristics have a genetic basis by comparing the extent to which both twins have the same characteristics.
• twin studies- concordance rate

  Higher concordance rates between identical (monozygotic) twins than non (dizygotic) twins tend to be taken as evidence of a genetic basis
• what are monozygotic twins


  • are identical & share 100% similarity of their genetic material
• what are dizygotic twins

  • non-identical & share about 50% similarity of genetic material
• Natural selection


  Proposed by Charles Darwin. States any genetic behaviour that enhances survival gets passed on to the next generation

  
  

  They are called adaptive as they give the possessor certain advantages
• Strengths of biological approach

  - supporting evidence of genetic explanation:

  twin studies, McGuffin conducted a twin study on depression & found a concordance rate for 46% MZ & 20% DZ

  
  

  - Has real life applications increased understanding of the brain has led to the development of drugs that treat mental disorders