Biological Approach

• Monozygotic


  Twins that share 100% of genes
• Dizygotic


  Twins that share 50% of genes
• Genotype

  The genetic makeup of an individual, the particular set of genes the individual possesses
• Phenotype

  The observable characteristics shown by an individual that are a result of both genes and the environment
• Concordance rate


  The extent to which twins share the same characteristics
• Evolution


  Fitness is all about how well an organism is adapted to its environment, a gene that Is adapted at one time may become maladaptive if the environment changes
• Neurochemical basis of behaviour


  much of our thought and behaviour relies on chemical transmission in our brain by using neurotransmitters, an imbalance of neurochemicals can cause mental disorders