Biological approach

• What does this approach say ?

  • all thoughts, feelings and behaviour have a biological basis
• What are the three assumptions ?

  1. the genetic makeup of an individual influences their behaviour
  2. chemicals in the body such as hormones+ neurotransmitters will influence behaviour
  3. everything psychological is first biological
• What are the 3 main parts involved ?

  • genes
  • evolution
  • twin studies
• Role of genes ?

  • genetic makeup of an individual can influence behaviour
  • genetics can explain mental illness, personality + criminal behaviour
  • low levels of seratonin increase chance of depression
• Twins studies ?

  • can observe the role of genes through MZ twins as they share identical DNA.
  • a high concordance rate suggests genetics play a role in behaviour
  • concordance rates might not be 100% as phenotypes may play a role
• What are the strengths of twin studies ?

  • natural environment
  • concordance rates useful
• What are the weaknesses of twin studies ?

  • twins share same environmentMZ twins are 3 in 1000 births
• why are adoptions studies better ?

  • as avoid shared environment problem
• Why are family studies useful ?

  • shows how genes are passed down + how environmental impacts behaviour
• What is the role of evolution ?

  • process of a species adapting to its environment
  • genetic material is passed on through generations to pass on behaviour which will aid survival e.g fight/flight response
• What are Mz twins ?


  Same sex from single. Fertilised ovum that splits
• What are DZ twins ?


  Same or different sex from seperate eggs + sperm
• What’s is a genotype ?

  Genetic makeup of an individual set of genes an individual possesses
• What is a phenotype ?


  Observable characteristics from the interaction of genes + environment
• What is the evaluation ?

  1. real life application
  2. uses scientific methods
  3. ignores environmental influences
• What is real life application ?

  • drugs for depression work by increase levels of seratonin
  • strength as helps people be happy + function a normal life again

  - however drugs don’t work for everyone so other factors must be. Involved
• Use of scientific methods ?

  • brain scans to look at people who have had a stroke
  • high levels of dontok enable reliability + increase validity
  • brain scans are objective
  • however may lack ecological validity.
• Ignored environmental influences ?

  • concordance rate not 100%
  • must be interaction with environment
  • might of lived in a toxic environment