Biological

• ASSUMPTIONS

  • sees human behaviour as emerging from the physiology and biology of the body
  • must look to biological structures to fully understand human behaviour
  • brain can be used to explain thinking, and behaviour can be explained using the flight or flight (nervous system)
  • neurochemistry influences our thinking, such as levels of dopamine in the serotonin in the OFC and B.G. have been thought to implicate OCD
• Genetic basis of behaviour

  • genes are contained on chromosomes
  • each individual is typically born with 23 pairs of chromosomes that have been inherited from birth parents
  • genes are carriers of information for specific characteristics
  • how the characteristics develop depends on the interaction with the environment
  • genotype - an individual's genetic makeuo occurs at conception - unique to them
  • phenotype- the product of what happens when the genotype interacts with the genotype
• Phenylketonuria

  • a rare genetic disorder that can be detected in babies using a heel prick test
  • if left unchecked, it can cause learning difficulties in those who carry the genotype
  • if checked early enough, the child is placed on a restricted diet that can help them develop normally with no complications
  • shows how children can be pre disposed to a disorder BUT effects can be over-ridden by environmental intervention
  • influenced by both nature and nurture
• Behaviour geneticists study whether behavioural characteristics such as intelligence, personality, mental disorder are inherited in the same way as physical characteristics
• Twin studies

  • used to investigate whether certain behaviours are a result of the environment of genes
  • compare concordance between MZ and DZ
  • Gottesman
  • looked at concordance of schizophrenia
  • 48% MZ
  • 17% DZ
  • shows that there is a role for genetic in this illness
• Evolution and behaviour

  • evolution is thought to develop in the same way as physical characterstics of humans
  • Charles Darwin proposed the theory of natural selection
  • adaptive characterstics will continue in future generations
  • biological psychologists believe that physiological characterstics such as intelligence and aggression have evolved as they offer a survival advantage
• A03

  • A strength is that there is supporting evidence from twin studies. HOWEVER, the concordance rates are never 100% and so there must be environmental influence.
• A03

  • A further strength to this explanation is that evidence for the role of the brain in behaviour comes from brain scans
  • fMRI has shown what parts of the brain are active during long term memory tasks and speech reproduction
  • These are scientific methods that have been used to show the higher activityin the OFC and BG, thus providing objective evidence for the role of the brain in OCD
• A03

  • Value as it has allowed for development of treatments that target hormones and neurotransmitters, e.g. anti depressants and depression (SSRIs prevent the reuptake of serotonin to increase levels in the body)
• A03

  • Criticised for being reductionist because it oversimplifies complex human behaviour to the levels of genes and hormones and therefore ignores the factors of the environment that may come into play
• A03

  • Strongest supporters of the nature nurture debate, which is a strength, as it argues the genetic influence on behaviour