5.biological approach

• the biological approach suggests that everything psychological is at first biological
• understanding our brain structure and function can explain our thoughts and behaviour
• behaviour genetics study whether behavioural characteristics (intelligence, personality and mental disorder) are inherited in same way as physical characteristics such as high and eye colour
• identical twins are also known as monozygotic
• non identical twins are known as dizygotic
• monozygotic twins are found to have a higher concordance rate compared to dizygotic twins, this is because monozygotic twins share 100% of each others genes whilst dizygotic twins share about 50%
• persons genotype is their actual genetic makeup
• persons phenotype is the way that genes are expressed through physical, behavioural and psychological characteristics
• expression of genotype is influenced by environmental factors
• monozygotic twins have the same genotypes but different phenotypes
• by doing twin studies many biological psychologists would accept that much human behaviour depends upon an interaction between inherited factors (nature) and the environment (nurture)
• evolution are changes in inherited characteristics in a biological population over generations
• in 19th century, Charles Darwin proposed a theory to explain evolution - theory of natural selection
• the main principle to natural selection is that any genetically determined behaviour that enhances an individuals survival will continue in future generations
• neurochemistry relates to chemicals in the brain that regulate psychological functioning
• biological structures are arrangements or organisations of parts to form an organ, system or living thing
• phenylketonuria (PKU) is a rare genetic disorder that can be detected in babies using a heel prick test. if left unchecked, PKU causes severe learning difficulties in those who carry the genotype . if detected early the child can be placed on a restricted diet and will develop normally without complications
• evaluation - scientific methods of investigation +

  • based on reliable data as technology allows us to use unbiased techniques such as brain scanning - fMRIs and EEGs
• evaluation - real life application +

  • increased understanding of brain processes led to development of psychoactive drugs that treat serious mental illnesses
• evaluation - casual conclusion

  • offers explanations for mental illnesses by looking at the action of neurotransmitters in the brain
  • but, this evidence comes from studies that show particular drug references mental disorder symptoms, assuming the neurochemical in the drug causes the disorder - this is like assuming the cause of a headache is lack of paracetamol because paracetamol is effective in reducing symptoms
• evaluation - determinist view of behaviour

  • sees human behaviour as governed by internal, biological causes in which we have no control
  • implication for legal system, as offenders are seen as responsible for their actions
• evaluation - cannot separate nature and nurture

  • members of the same family have genetic similarities - biological approach believes similarities in the way they look or behave must be genetic, but doesnt take into account similar environmental conditions
• twin studies are used to determine the likelihood that certain traits have a genetic bases by comparing concordance rates between pairs of twins