biological approach

• assumption: all behaviour is down to biological processes, and these are

  • genes
  • biological structures
  • evolution
  • neurochemistry
• genes carry information that codes for physical and psychological features

  your genotype is your genetic makeup (coding)

  phenotypes are observable traits that are due to genes interacting with the environment
• e.g genotype - SERT gene to develop depression

  phenotype - depression expressed due to a traumatic life experience triggering the gene
• monozygotic twins are genetically identical and share 100% of their genes.

  dizygotic twins are non identical and share roughly 50% of their genes
• concordance rate - percentage of the twins who share a certain behaviour with their twin
• MZ concordance is higher than DZ concordance - genes must play a role in this behaviour
• MZ concordance is not 100% - the environment must play some part in the behaviour
• No difference between MZ and DZ concordance rates - no genetic influence on behaviour
• biological structures:

  the nervous system influences our fight or flight reaction to danger.

  structures within the brain influence our behaviour.
• The brain is in charge of decision making, attention and higher order thinking.

  blue - frontal lobe

  pink - parietal lobe

  green- temporal lobe

  purple- occipital lobe

  
• brain structure example:

  Brain scanning has shown people with OCD have higher activity in the orbital frontal cortex (OFC) which suggests that activity in this area is responsible for obsessive thoughts.
• evolutionary psychology suggests that all human behaviour had been caused by the evolutionary pressures to:

  • survive
  • reproduce
• evolution key ideas:

  • adaptive behaviours
  • natural selection
  • sexual selection
• neurochemistry - the study of chemicals that influence the brain.
• hormones - chemical messengers that travel through the bloodstream and are released by glands
• fight or flight example:

  adrenaline (hormone) is released by the adrenal gland during fight or flight (behaviour).

  it leads to bodily changes such as:

  • increased breathing rate
  • increased heart rate
  • slowing down of digestion
• neurotransmitters are chemical messengers that travel via the nervous system.

  they travel from neuron to neuron (synaptic transmission)
• neurotransmitter example:

  Dopamine (neurotransmitter) has been found higher in people with schizophrenia. this can lead to sensory overload, hallucinations and delusions
• evaluations:

  🙂 supporting evidence from twin studies

  ☹️ ignores the role of the environment

  ☹️ biological determinism

  🙂 practical application - antipsychotics to treat schizophrenia