Bio approach

• Brain areas responsible for thinking and behaviour

  • Language is governed by Broca's area (controls production of speech) and Wernicke's area (controls comprehension of speech)
• Genetic influence on behaviour

  Schizophrenia is at least partly result of inheriting a faulty gene
• Chemical processes in the brain

  Can influence behaviour
• Neurotransmitters


  Brain relies on them to send signals between neurons
• Too much/too little neurotransmitters

  Can result in over or under activity, leading to changes in thinking, feeling and behaviour
• Effects of neurotransmitters


  • Increased testosterone leads to increased social responsiveness
  • Increased oxytocin leads to increased nurturing
• Quantitative, objective and well controlled research

  • Likely to produce valid scientific evidence
• Investigating genetic influence using twin, family history and adoption studies

  1. Compare individuals with different degrees of genetic relatedness to see how similar they are in relation to a particular trait

  2. Investigate using a pair of identical twins where one has the abnormality and the other doesn't

  3. Calculate concordance rate - the extent to which 2 individuals are similar to each other in terms of a particular trait
• Cardno showed concordance rate of 40% for MZ and 5.3% for DZ twins for schizophrenia
• Interactions of nature (gene) and nurture (environment)


  Determine which has the most influence on behaviour
• MZ twins share 100% of their genes, DZ twins share 50%
• Regular siblings not 100% same environment, but brought up the same e.g. more strict with eldest, opposite for younger
• Children more likely to develop schizophrenia if parent has it

  Indicates genetic influence
• If biological family has schizophrenia but not adopted parents, and child develops it

  Indicates genetic influence
• If adopted parents have schizophrenia but not biological parents, and child develops it


  Indicates environmental influence
• Adoption is not random, adopted parents usually have similar parenting styles to biological family
• Genotype


  The genetic makeup of an individual that is passed from generation to generation
• Phenotype


  The observable characteristics of an individual, a consequence of the interaction of genotype with the environment
• Darwin (1859) proposed the theory of natural selection
• Genetically determined behaviour that enhances survival and reproduction


  • Will be passed on to future generations
  • Such genes are described as adaptive and give the possessor and their offspring advantages
• Adaptive behaviours


  • Attachment behaviours in newborns promote survival
• Bowlby (1969) suggests attachment is a vital adaptive quality that has evolved to increase the chance of survival through proximity-seeking behaviour
• Vulnerable to predators without attachment to a primary caregiver

  More protected so more likely to survive
• Stress


  Has a survival advantage as it allows avoidance of real physical threats by triggering a fight or flight response
• Adrenal glands


  • Located behind the kidneys
  • Adrenal cortex produces cortisol which regulates cardiovascular and anti-inflammatory functions
  • Adrenal medulla produces adrenaline which prepares the body for the fight or flight response
• Cortisol production


  Increased in response to stress
• Low cortisol levels


  Blood pressure is low
• Adrenal medulla


  Produces adrenaline which increases heart rate by binding to receptors on heart muscle
• Endocrine system


  A network of glands that manufacture and secrete chemical messengers called hormones
• Hypothalamus


  The "master gland" that produces hormones and regulates the release of hormones from other glands
• Pituitary gland


  • Controlled by the hypothalamus
  • Anterior pituitary produces ACTH which stimulates the adrenal glands to produce cortisol in response to stress
  • Anterior pituitary also produces luteinizing hormone and follicle stimulating hormones for reproductive functioning
• Posterior pituitary


  • Releases oxytocin which stimulates contraction of the uterus during childbirth