Biological approach

• if we want to understand human behaviour, we must look to biological structures and processes within the body like genes and neurochemistry
• from the biological approach, the mind lives in the brain - meaning 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
• 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 (underproduction of serotonin in OCD)
• psychological characteristics (e.g. intelligence) are inherited. twin studies are used to investigate genetic influences. concordance rates between twins are calculated - the extent to which twins share the same characteristic

  higher concordance rates among identical (MZ) twins (genetically 100% the same) and non-identical (DZ) twins (50% the same) is evidence of a genetic basis
• • a persons genotype is their actual genetic makeup
  • phenotype is the way genes are expressed through physical, behavioural and psychological characteristics
  • this expression of genotype is influenced by environmental factors
  • e.g. PKU is a genetic disorder that can be prevented by a restricted diet
  • this suggests that much of human behaviour depends on the interaction of nature and nurture
• theory of evolution used by biological approach to explain behaviour

  • darwin proposed theory of evolution
  • any genetically determined behaviour that enhances survival and reproduction will be passed onto future generations
  • such genes are described as adoptive and give the possessor and their offspring advantages
  • for instance, attachment behaviours in newborns promote survival and are therefore adaptive and naturally selected
• one strength: is its real-world application - understanding of neurochemical processes in the brain has led to the use of psychoactive drugs to treat serious mental disorders - e.g. 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
• another strength: the biological 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 - these include scanning techniques like fMRI, which assess biological processes in ways that aren't open to bias - this means that the biological approach is based on objective and reliable data
• limitation: biological explanations are deterministic - they tend to be determinist in that they see human behaviour as governed by internal, genetic causes over which we have no control - however, the way genotype is expressed is heavily influenced by the environment - not even genetically identical twins look and think exactly the same - this suggests that the biological view id too simplistic and ignores the mediating effects of the environment
• another limitation: it fails to consider individual differences - although the biological approach acknowledges that individuals differ from one another, it doesn't take into account how these differences might affect an individual's response to treatment - for example, not all patients respond well to antidepressant medication, so we need to look beyond just the chemical imbalances in the brain to find out why certain treatments work better for some people than others