the biological approach

• Assumptions of the Biological approach

  Everything psychological was at first biological.

  All behaviour has a physical cause.

  Genes affect behaviour and influence psychological differences between people.

  Psychologists should study the brain, nervous system and other biological systems to understand behaviour.
• The influence of biological structures on behaviour - hormones


  Hormones can have long-term effects on both the body and behaviour. For example, sex hormones like testosterone and oestrogen play roles in developing gender-specific physical features. Testosterone is associated with male traits and is linked to increased aggression.
• Physiology


  The study of the body and its parts and how they function.
• Genetic factors


  Each individual possesses a unique combination of genetic instructions.

  Genes code for characteristics such as eye color but also for the structure of the nervous system and for the functioning of the nervous system.
• Twin studies


  Determines the involvement of genetic factors.

  We compare the concordance rate of MZ twins to the concordance rate of DZ twins.
• Family studies


  Research conducted among siblings, parents or children to assess evidence for genetic links for characteristics.

  Mostly used to identify the degree of risk of relatives developing mental disorders that other family members suffer from.
• Adoption studies


  These evaluate the interactions of genetic and environmental factors in human characteristics.
• Genotype


  Genetic code that is written in the DNA.

  Genetic makeup of an individual, present in each of your cells.
• Phenotype


  Physical representation that results from the individual's genotype.
• Evolution


  Charles Darwin proposed the theory of natural selection.

  Genetically determined characteristics or behaviour, that enhance our chances of survival and reproduction would be passed on to the next generation and become more common in a population, whereas traits that do not enhance survival will gradually disappear.
• Concordance rates


  Psychologists study the genetic inheritance of behaviour using concordance rates, the probability that a person will have a disorder if a relative does. Higher concordance rates among genetically closer relatives suggest a genetic influence.
• Genetic inheritance


  Both parents contribute one half of the gene material that is needed to create offspring.
• How does evolution explain our behaviour?

  Evolutionary psychologists argue that inherited, innate behaviours, providing survival advantages, are selected for and become more common in future generations of a species.

  Example - Aggression: less aggressive males were less likely to reproduce, leading to aggressive traits being passed on.
• + Practical applications to drug treatments


  E - Research into the role of neurochemical imbalances in depression has led to the development of SSRIs. SSRIs are a type of antidepressant drug that inhibits the reabsorption of serotonin, increasing the availability of serotonin.

  E - This increases the validity of the biological approach as it has resulted in effective treatments.

  L - However, SSRIs are not effective for everybody. Some people may need therapy as well as drug treatment.
• + Scientific method and controlled experiments


  E - Brain scans and drug trials are used to provide information about the brain's neural and biological processes.

  E - Research is done under strict conditions and, therefore, explanations can be scientifically tested and the results will be valid.

  L - However, the strict conditions that the research into the biological approach uses means it lacks ecological validity for the conditions in these lab studies are unlikely to occur in real life.
• / Doesn't take into account environmental factors


  E - Mednick et al found that children were most at risk of developing criminal behaviour if both their adoptive and biological parents were convicted of crimes.

  E - This suggests that it is not always nature that influences our behaviour. Our behaviour can also be influenced by our surroundings.

  L - Therefore, this decreases the validity of the biological approach for it does not give an explanation for nurture's impact on behaviour.
• / Deterministic


  E - According to this approach behaviour is caused by our genes and the activity of neurotransmitters in the brain.

  E - Claims that all thought and behaviour is caused by factors outside of our control.

  L - Therefore, this ignores the idea of free will and that we as humans have control over our behaviour we are not simply pre-programmed by genes.
• / Reductionist


  E - All human behaviour is reduced down to just physical processes such as activity of neurotransmitters (e.g. OCD is explained in terms of levels of serotonin in the brain).

  E - It attempts to reduce all aspects of human behaviour down to just one level of explanation. This underestimates the role of our environment in behaviour.

  L - However, reductionism allows researchers to investigate behaviour scientifically, by isolating just one factor.