biological

• How biological psychologists explain behaviour

  evolutionary

  genes -> DNA

  nature -> born with it

  neurotransmitters

  hormones
• Biological assumptions

  everything psychological is biological: must look to biological structures & processes within the body

  understanding the brain's structure & function can explain thoughts & behaviour

  the mind & body are one in the same: the mind lives in the brain, all thoughts, feelings & behaviour have a physical basis

  humans are no different from animals as we share the same basic biology

  evolution & genes are the basis of behaviour, as survival & the ability to reproduce is central in all species
• Physiological processes


  behaviour is controlled by the nervous system (NS).

  in the central nervous system (CNS) specific cells (neurons) communicate with each other chemically (neurotransmitters) at their junctions (synapses).

  the peripheral nervous systems includes the autonomic nervous system (ANS) which controls the automatic processes in the body.
• Hormones


  chemical messengers that act throughout the body by travelling through the bloodstream
• Neurotransmitters


  chemicals in the brain that transmit messages
• Influence of genes

  behaviour geneticists' study whether behavioural characteristics, eg. intelligence are inherited the same way as physical characteristics, eg. eye colour
• Monozygotic (MZ) twins


  share 100% of each other's genes (identical)
• Dizygotic (DZ) twins


  share 50% of each other's genes (fraternal)
• Concordance rates

  the extent to which both twins share the same characteristics (similarity)
• Adoption studies

  if a characteristic is genetic the children should show a greater similarity to their biological parents than their adopted parents.

  if there's a greater similarity between the child & their adoptive parents, it provides evidence for environmental influence.

  A high concordance rate between the occurrence of the characteristic in the adopted child & their birth parents suggests a genetic basis for the characteristic, whereas a high concordance rate with the adoptive family suggests environmental factors are more important.
• Genotype


  the actual genetic makeup of a persons(the 23 pairs of chromosomes): genetic composition
• Phenotype


  the expression of their genetic makeup: observable characteristics)
• Evolution

  originating from the work of Charles Darwin, evolutionary theory sees survival & the ability to reproduce as key to all aspects of behaviour
• Strengths

  Makes use of a range of precise & objective methods, eg. scanning techniques which asses biological processes in ways that aren't open to bias so is reliable as uses scientific methods.

  Led to the use of psychoactive drugs to treat serious mental disorders, eg. antipsychotics to treat schizophrenia, so beneficial for people in the real world.

  Offers explanations for mental illness in terms of the actions of neurotransmitters in the brain, evidence comes from studies showing a particular drug reduces symptoms of a mental disorder.
• Weaknesses

  -assumes the neurochemical in drug medication causes the disorder - an association is not a cause - hasn't discovered an a cause just an association

  -antidepressants don't work for everyone: Cipriani et al - compared 21 antidepressant drugs & found wide variations in effectiveness, suggests brain chemistry alone may not account for all cases of depression

  -tends to be determinist, see human behaviour as governed by internal, genetic causes over which we have no choice, but the phenotype is influenced by the environment, so biological view is too simplistic & ignores mediating effects of environment