biological approach

• everything psychological is first biological

  • if we want to fully understand human behaviour we must look to biological structures and processes within the body, such as genes and neurochemistry
  • a full understanding of human behaviour will look at the underlying biological processes that cause it
• mind and body are one and the same

  • from the biological approach = the mind lives in the brain = meaning that all thoughts, feelings and behaviour ultimately have a physical basis
  • this is in contrast to the cognitive approach = which sees the mind as separate from the brain
• neurochemical basis of behaviour

  • neurochemistry = refers to the action of chemicals in the brain (neurotransmitters transmit messages)
  • an imbalance of neurotransmitters may be a cause of some mental disorders (eg underproduction of serotonin in OCD)
• genetic basis of behaviour

  • psychological characteristics (eg intelligence) are inherited
  • twin studies:
  • used to investigate genetic influences
  • concordance rate between twins are calculated = the extent to which twins share the same characteristic)
  • higher concordance rates among identical (monozygotic, MZ) twins (genetically 100% the same) than non-identical twins(dizygotic, DZ) twins (about 50% the same)
  • evidence of a genetic basis
• genotype vs phenotype

  • genotype = a person's actual genetic make-up
  • phenotype = the way that genes are expressed through physical, behavioural and psychological characteristics
  • the expression of genotype (phenotype) is influenced by environmental factors
  • eg = phenylketonuria (PKU) = a genetic disorder that can be prevented by a restricted disorder
  • this suggests that much of human behaviour depends on the interaction of nature and nurture
• theory of evolution

  • Darwin = proposed the theory of natural selection
  • any genetically determined behaviour that enhances survival and reproduction will be passed on to future generations
  • such genes are described as 'adaptive' and give the possessor and their offspring advantages
  • eg = attachment behaviours in newborns promote survival and are therefore adaptive and naturally selected
• strength = RWA

  • understanding of neurochemical processes in the brain has led to the use of psychoactive drugs to treat serious mental disorders
  • eg = drugs that treat clinical depression increase levels of the neurotransmitter serotonin at the synapse and reduce depressive symptoms
  • this means that people with depression are able to manage their condition and live a relatively normal life, rather than being confined to hospital
• counterpoint RWA

  • antidepressants do not work for everyone
  • Cipriani et al = compared 21 antidepressant drugs and found wide variations in their effectiveness
  • this challenges the value of the biological approach as it suggests that brain chemistry alone may not account for all cases of depression
• strength = approach uses scientific methods

  • in order to investigate both genetic and neurochemical factors, the biological approach makes use of a range of precise and objective methods
  • eg = scanning techniques (eg fMRI) which assess biological processes in ways that are not open to bias
  • means that the biological approach is based on objective and reliable data
• limitation = biological explanations are determinist

  • biological explanations tend to be determinist in that they see human behaviour as governed by internal, genetic causes over which we have no control
  • BUT = the way genotype is expressed (phenotype) is heavily influenced by the environment
  • not even genetically identical twins look and think exactly the same
  • this suggests that the biological view is too simplistic and ignores the mediating effects of the environment
• extra evaluation = natural selection

  • critics of Darwin (eg Popper) = claim it is not possible to show evolution happening, only that it has taken place (unfalsifiable)
  • HOWEVER = others argue that natural selection is supported by fossil records
  • eg = gradually changing forms from dinosaurs to birds
  • this suggests that although natural selection is not able to tell us what species will evolve into, it provides an adequate account of past development