KEY CONCEPTS OF THE BIOLOGICAL APPROACH

• Genetics (heritability)

  • Psychological characteristics e.g. intelligence are inherited in a similar way to height, eye colour 
  • Monozygotic (MZ) twins- identical (one egg, split into 2), share 100% of their DNA
  • Dizygotic (DZ) twins- non-identical (fraternal), share 50% of their DNA
  • MZ twins have an increased concordance rate of developing schizophrenia than DZ twins 
  • Identical twins have the same genotype
  • However the way genes are expressed differs (phenotype)
  • Bio Psychologists believe that much of behaviour depends on inherited genes and the environment 
• KEY POINT:

  • Biological Psychologists are also called “Nativists”
• Neural (Neurochemistry)

  • Chemicals play a role in determining behaviour
  • At Synapses- signals are sent between neurones by neurotransmitters
  • Imbalance of neurotransmitters- atypical behaviour
  • EXAMPLE: Low levels of serotonin- depression, OCD
• Neural (Brain Structure)

  • Another belief- structure of organs e.g. brain, CNS, peripheral nervous system (PNS) determines our behaviour
  • Different lobes of the brain- linked with general functions
  • EXAMPLE: Occipital Lobe- associated with visual perception
• GENES:

  • Evolution occurs through genes
  • Natural selection by Darwin- survival of the fittest
  • Evolutionary advantage- passed from one generation to the next- those that don’t get the genes die out