bio A AO1

• what does the biological approach suggest

  • everything psychological is at first biological
  • to fully understand human behaviour , we must look into biological structures and processes within the body
• what is neurochemistry

  refers to the action of chemicals in the brain

  • much of our thought and behaviour relies on chemical transmission in the brain - this occurs through neurotransmitters
• what happens when theres an imbalance of neurochemicals in the brain

  • its a possible cause of mental disorder
  • e.g. low levels of neurotransmitter serotonin in OCD and overproduction of dopamime in schizophrenia
• what are twin studies used for

  to investigate whether certain psychological characteristic have a genetic basis - achieved by concordance rates
• whats concordance rates


  the extent to which twins share the same characteristic
• if a characteristic is genetic we expect all identical (monozygotic) tins to be concordant (share 100 % same genes)
• non identical twins (dizygotic) share about 50 % of the same genes
• both monozygotic and dizygotic twins , the environment is assumed to be constant
• genotype


  actual genetic make up
• phenotype


  the way genes are expressed through physical , behavioural and psychological characteristics
• identical twins have the same genes but their phenotype is different - illustrates that much of human behaviour depends upon interaction between inherited factors and the environment
• theory of natural selection

  • proposed by charles darwin
  • main principle - any genetically determined behaviour that enhances an individuals survival will continue for generations
  • in nature - this selection takes place naturally