Biological approach

• Biological Approach

  Everything psychological is at first biological - to fully understand human behaviour we must look at biological structures and processes within the body, like genes, neurochemistry and the nervous system
• Behaviours


  • Inherited the same way physical characteristics like height or eye colour are
  • Neurochemistry also explains behaviour, for example low serotonin levels in OCD
• Concordance rates between twins

  The extent to which twins share characteristics
• Higher concordance rates among identical (monozygotic, MZ) twins


  Evidence of a genetic basis
• Concordance rates for OCD

  • 68% of MZ twins both have OCD compared with 31% of DZ twins (Nestadt et al 2010)
• Genotype


  A person's actual genetic makeup
• Phenotype

  How genes are expressed PHYSICALLY, behaviourally or psychologically
• Expression of genotype (phenotype)

  Influenced by environmental factors
• Much of human behaviour depends on the interaction of nature & nurture
• Natural selection


  Any genetically determined behaviour that enhanced survival & reproduction will pass onto future generations
• Adaptive genes


  Give the possessor and their offspring advantages
• Adaptive behaviour


  • Attachment behaviour in new-borns promote survival
• Strength of Biological Approach

  • Use of scientific methods of investigation to measure biological and neural processes in ways that are not open to bias
  • Increased understanding on biochemical processes in the brain has led to the development of psychoactive drugs that treat serious mental disorders