biological approach

• Biological approach


  Suggests that everything psychological is at first biological, so to fully understand human behaviour, we must look to biological structures and processes within the body
• Mind


  Lives in the brain - meaning that all thought, feelings and behaviour ultimately have a physical basis
• Neurochemistry


  The action of chemicals in the brain. Much of our thought and behaviour relies on chemical transmission in the brain using neurotransmitters
• An imbalance of neurochemicals in the brain has been implicated as a possible cause of mental disorder, for example low levels of the neurotransmitter serotonin in OCD and overproduction of dopamine in schizophrenia
• Genotype


  A person's actual genetic make-up
• Phenotype


  The way that genes are expressed through physical, behavioural and psychological characteristics
• Despite having the same genes, the way identical twins' genes are expressed (the phenotype) is different
• Much of human behaviour depends upon an interaction between inherited factors (nature) and the environment (nurture)
• Natural selection


  The theory proposed by Charles Darwin that any genetically determined behaviour that enhances an individual's survival (and reproduction) will continue in future generations
• The evolution of animals and plants is a fact
• Genetically determined behaviour that enhances an individual's survival and reproduction


  Will continue in future generations
• If the individual survives but does not reproduce, the traits do not remain in the gene pool for successive generations
• Giraffes' long necks are an evolutionary advantage in obtaining food
• Bowlby's attachment theory is related to the biological approach
• One strength of the biological approach is that it has real-world application, such as the use of psychoactive drugs to treat serious mental disorders
• Another strength of the biological approach is that it uses scientific methods of investigation, such as scanning techniques like MRIs and EEGs
• One limitation of the biological approach is that it is determinist, seeing human behaviour as governed by internal genetic causes over which we have no control
• The biological view is often too simplistic and ignores the mediating effects of the environment
• Critics claim that it is not possible to falsify the theory of natural selection, as we cannot show evolution happening, we can only deduce it has taken place
• Others claim that the basic principles of natural selection are supported by fossil records
• In a study of depression, one way to investigate the genetic basis would be to compare the concordance rates for identical twins versus non-identical twins
• Monozygotic twins share 100% of their genes, while dizygotic twins share around 50%
• If a characteristic is genetic, we would expect all identical twins to be concordant (share the same characteristic), whereas this would not be true for non-identical twins
• The environment is assumed to be constant in twin studies investigating the genetic basis of behaviour
• The biological approach suggests that a violent criminal could excuse their actions by claiming their behaviour was controlled by a 'crime gene'