APPROACHES - BIOLOGICAL APPROACH

• assumptions 

  -everything psychological is first biological  -biological structures underpin all behaviour  -genes affect our behaviour  -different hormones and chemicals in the brain cause different outcomes  -the mind lives in the brain 
• what does the biological approach combine? 

  The biological approach is a combination of biology and psychology. It argues that there is a physiological explanation for all behaviour. 
• genotypes and phenotypes 

  Genotype = a persons genetic make-up.  Phenotype = how a persons genes are expressed in their environment. 

  twin studies 
• Twin studies are used to support the biological approach. Twin studies help explain genotypes, phenotypes and how they are expressed. They are good for looking at nature vs nurture. 

  monozygotic twins vs dizygotic twins 

  Monozygotic twins = share 100% same genes.  Dizygotic twins = share 50% same genes (just like any siblings they are just born at the same time). 
• genetic basis of behaviour 

  Our biology and genes have a significant role in shaping who we are as well as how we behave. Genes we inherit from our parents give instructions for our behavioural traits and physical characteristics. Interactions between our genes and our environment shape our phenotype.  (Environment can also change our behaviour.) 

  neurochemical basis of behaviour 
• Our nervous system influences our behaviours (central & peripheral). Neurones communicate via electrical impulses and neurotransmitters. Imbalances in neurotransmitters can led to abnormal behaviours e.g., imbalances in serotonin and dopamine can link to schizophrenia and OCD. This proves that our biology does impact our behaviours. 
• evolution on behaviour 

  Charles Darwin's theory of natural selection can be used to show how evolution has changed/ influenced behaviour. Genes that enhance an individuals chance of survival are passed to the next generation - all behaviours have evolved as a survival mechanism. Behaviours change to help us survive.  -could use example of farmers and selective breeding. 
• Strength(s):  -scientific methods. Supported by scanning techniques like fMRI and PET scans which produce very clear, objective data.  -real-world application. Antidepressants are used to increase serotonin levels in the brain and help treat depression. Psychoactive drugs are used in the treatment of serious mental illnesses.
• Weakness(es): -biological determinism. This approach only looks at biological factors on our behaviours. It ignores how people have free will and can behave how they wish to.