APPROACH

• KEY ASSUMPTIONS?

  • all thoughts and behaviours have a physical origin
  • e.g. genes/ biological structures/ neurochemistry/ evolutionary adaption
• METHODS OF INVESTIGATION?

  • twin studies
  • family studies
  • adoption studies
  • studying using brain scanning (EEG/ MRI)
  • drug trials
• INFLUENCE OF GENES?

  • suggests genes influence our behaviour
  • investigated using twin studies and comparing concordance rates
  • e.g. NESTADT'S OCD: 68% for monozygotic, 31% for dizygotic
  • can argue OCD has biological influences (however monozygotic twins treated more similarly than dizygotic)
• GENETIC BASIS OF BEHAVIOUR?

  • identical twins have identical genes
  • but do not behave identically due to environmental influences
  • not all people with predisposition to a disorder develop it
  • explained by diathesis stress model (genetic predisposition -> healthy environment)
• BIOLOGICAL STRUCTURES?

  • suggests structure of areas in our brain influence behaviour
  • e.g. hippocampus damage cause HM memory loss
  • e.g. damage to prefrontal cortex causes OCD
• NEUROCHEMISTRY?

  • suggests activity of hormones and neurotransmitters influence our behaviour
  • e.g. testosterone = aggression
  • e.g. serotonin/ dopamine = OCD
• EVOLUTION?

  • suggests challenges faced by our ancestors influence our behaviour
  • e.g. behaviours of children during infancy (social releasers, being overly alert to threats)
  • Adaption to environment -> breeding of fittest -> common genetic material between species
• CONCORDANCE RATES?

  likelihood of both twins sharing the same characteristic
• GENOTYPE?

  genes an individual possesses
• PHENOTYPE?

  observable traits/ characteristics shown by an individual