Biological Approach

• Assumptions of the Biological Approach

  • Psychology should be seen as a science, to be studied in a scientific manner (usually in a laboratory)
  • Thinking and behavior can be explained in terms of biological factors, e.g., genes & nervous system
  • Human genes have evolved over millions of years to adapt behavior to the environment
  • Patterns of behavior can be inherited. Therefore, most behavior will have an adaptive/evolutionary purpose
  • Humans are similar to animals. Therefore, research can be carried out on animals as well as humans
  • Follows a nomothetic approach as it focuses on establishing laws and theories about the effects of physiological and biochemical processes that apply to all people
• What affects behaviour


  • Neurochemistry
  • Genetics
  • Bio-Structure
• Neurochemistry


  The study of chemicals and their reactions in the nervous system
• Imbalances of neurotransmitters (chemicals) in the brain

  Can affect behaviour (ex. high levels of dopamine associated with schizophrenia)
• Genetics


  Genetic basis of behaviour → refers to the idea that inherited genes can be responsible for behaviour as well as for physical characteristics
• Investigating genetic basis of behaviour

  1. Using twin studies

  2. Monozygotic twins (MZ) → Share 100% same genes and are identical

  3. Dizygotic twins (DZ) → Share 50% of the same genes are non-identical

  4. The concordance rate shows the percentage of the extant to which twins share the same characteristics
• Hereditary genes contain instructions as to how to develop
• Genes responsible for physical characteristics as well as behavioural traits
• Mestadt et al → found that 60-80% of our IQ is inherited and forms the genetic basis for OCD
• Bio-structure


  Refers to the structure of the brain and localisation of brain function
• Bio-structure


  • The basal ganglia is involved in cognitive and emotional behaviours, playing an important role on reward and reinforcement
• Genotype


  Person's unique genetic makeup that is coded in their chromosomes and fixed at conception (ex. heigh, eye colour, hair colour)
• Phenotype


  The way genes are expressed through physical, behavioural and psychological characteristics
• Expression of a genotype


  Inevitably influenced by environmental factors (ex. skin colour - skin exposure)
• Human behaviour depends on interaction between inherited factors (nature) and the environment (nurture)
• Natural selection


  Process described by Charles Darwin
• Natural selection


  • Genetically inherited behaviour which enhances an individuals survival and reproduction will be passed on to future generations
• Aggressive behaviour


  • Survival benefits such as warding off predators and competing for resources
• Reductionist - Evaluation


  • Biological explanations reduce complex behaviours into simplified bodily processes
  • For example the approach suggests that an illness such as schizophrenia is basically a complex physical-chemical system that has gone wrong
  • The psychiatrist R.D Laing 1965 claimed that such an approach ignores the experience of distress that goes along with any mental illness and is therefore at best an incomplete explanation
  • Reduces the validity of the approach as a simplified explanation may prevent us reaching a true understanding of the target behaviour
• Scientific Methods - Evaluation


  • Biological explanations such as localisation of brain function have clear variables that can be measured, tracked and examined.
  • Enables psychologists to conduct scientific research studying these variables using technologies such as scanning techniques (fMRI and PET scans)
  • For example Raine et al. made use of PET scans to compare 14 areas of the brain in murderers pleading NGRI compared with non-murderers
  • Examples show this approach fulfils scientific aims to conduct objective, well-controlled studies and demonstrate causal relationships
• Real life applications


  • Increased understanding of neurochemical processes in the brain is associated with the use of psychoactive drugs to trat serious mental health disorders
  • For example drug therapy has enabled many with mental disorders to live relatively normal lives outside mental hospitals
  • For example bipolar disorder has been successfully treated with drugs - Viguera et al. 2002 report that more than 60% of bipolar patients improve when taking the drug lithium.
  • Increases the value of the approach