AO1 Biological Approach

• What are the assumptions of the biological approach?

  Suggests that everything psychological has a biological basis, so to study human behave our, biological structures and processes must be considered. This can then be used to explain thoughts and behaviours
• Examples of biological structures and processes

  Genes, neurochemistry and the nervous system
• What studies are used to study genetic basis of behaviour?

  Twin studies
• How are twin studies used?

  Determine the likelihood that certain traits have a genetic basis by comparing concordance rates between pairs of twins to see the extent to which both twins share the same characteristics
• What is concordance rate?

  The probability that two people with shared genes will share a particular attribute, given that one of the individuals has that characteristic
• Monozygotic twins are genetically identical and share 100% of their genes
• Dizygotic twins share about 50% if each other’s genes
• What is genotype?


  The particular set of alleles (genes) that an organism has for a particular characteristic
• What is a phenotype?


  The visible characteristic of an individual which occur as a result of its genes and the environment
• Biological psychologists believe that human behaviour depends on the interaction between nature and nurture
• The theory of natural selection suggests that any genetically-determined behaviour, which gives the individual a selective advantage (increasing their chances of surviving, reproducing and passing down this beneficial allele onto their offspring), will be present in future generations. This is due to the genetic transmission of ‘beneficial’ characteristics from one generation to the next (i.e. heredity).