biological approach

• assumptions

  • everything psychological is first physiological
  • behaviour is a direct product of interactions within the body
  • different areas of biopsychology include genetics, brain structure and neurochemistry
• genetics

  • genetic information is passed on through the DNA in chromosomes, which are also passed down through generations from our parents (heredity)
  • biological psychologists believe there is a genetic basis for some behaviours, and therefore conduct twin studies to study the effects of genes on behaviour
  • identical twins (monozygotic twins) share 100% of their DNA, whereas non-identical twins (dizygotic twins) share around 50% of the same genes
  • if a study shows a higher concordance rate in MZ twins than DZ twins then we can assume a genetic basis for this behaviour
• twin studies- examples

  • schizophrenia (Grottesman 1991)- 48%, 17%
  • bipolar depression (Craddock and Jones 1999)- 40%, 5-10%
  • OCD (Nestadt et al 2010)- 68%, 31%
• genetics terms

  genotype- a particular set of genes that a person possesses

  phenotype- characteristics of an individual that are determined by both genes and environment

  genome- an individuals entire set of genes
• role of evolution

  natural selection- characteristics which are adaptive and help survival are more likely to be passed on

  sexual selection- attributes or behaviours which increase reproductive success are passed on and over-exaggerated over generations
• brain structures

  particular areas of the brain can be linked to different behaviours (localisation of function). This can be studied using brain damaged patients. If a particular function is lost after damage to a certain area of the brain, we can assume that this part of the brain was associated with that function.
• Phineas Gage

  • pole cracked into his skull
  • frontal cortex was damage (controls personality)
  • became unfriendly, indecisive and aggressive
  • suggests that structures of the brain are responsible for behaviour
• neurochemistry

  biopsychologists suggest that our behaviour may be determined by our neurochemistry (neurotransmitters and hormones)

  • serotonin- linked to depression and aggression, low levels in OCD, high levels in shyness and fearfulness
  • dopamine- linked to pleasure and can form addiction, also linked to schizophrenia and hallucinations
  • melatonin- helps to synchronise the stages of sleep
  • testosterone- linked to aggression and male characteristics
• biological approach- AO3

  • highly scientific
  • has real life application e.g drug therapies
  • hard to distinguish cause and effect
  • deterministic view of behaviour- rules out choice or free will
  • ignores environmental factors- had to separate nature and nurture
  • reductionist- ignores other suitable levels of explanation and the interaction of causal factor