nature nurture debate

• nature refers to the genetic influences on behavior e.g. neurochemistry, genes, neurotransmitters
• nurture refers to the environment, anything outside of body which can influence behavior
• nurture is genetic vulnerability which is triggered by an environmental stressor (nature) e.g. genes for OCD but combined with a trigger in environment causes OCD
• Epigenetics is a change in the genetic activity which doesnt change the genetic code, lifestyle events e.g smoking can leave a mark on our genes which can cause genes to switch on/off, has a lifelong influence and passed onto future generations
• examples of Nature is genetic basis for mental disorders like schizophrenia, there is 40% concordance rate in MZ twins and 7% in DZ. nature does play a part but the rate isnt 100% therefore nurture can have a significant role.
• example of nurture: Bandura social learning theory showed behavior is learnt through classical/operant conditioning as well as vicarious reinforcement, aggression towards bobo doll has genetic basis however how the children learnt to express their anger was learnt from observing and imitation.
• early nativist argues human characteristics are innate, a result of our genes
• Empiricists argue the mind is a blank slate at birth and shaped by interactions with the environment (behaviorist approach)
• Lerner identified different levels of the environment: Prenatal terms, postnatal experiences
• prenatal terms is mother smoking, listening to music
• post natal experiences can be social conditions child lives in when they grow up
• two ways to measure nature and nurture are concordance rates and heritiability
• concordance is the degree to which 2 people are similar on a particular trait
• heritability proportion of differences within a population in regards to a trait due to genes
• 0.01 is 1% which is little heritability, 1.0 is 100% which means genes is the entire contribution
• strength of nature-nurture


  adoption studies, if adopted children are more similar to their adoptive parents it suggests there is a nature influence, if adopted children are more like their biological parents then it is suggest a nurture influence, researcher complete a meta-analysis of adoption studies and found genetic influences accounted for 41% variations of aggression, shows research can separate nature and nurture.
• strength of nature nurture

  real world application of epigenetics, Nazis starved Dutch resulting in 20k deaths, women who fell pregnant during famine gave birth to low weight babies with a high risk of developing schizophrenia, this suggest life experiences can cause epigenetic markers which influence health of the offspring
• strength supporting interactionist approach

  nurture affects nature, Maguire et al studied posterior hippocampus of London taxi drivers as its associated with spatial awareness, Maguire found more grey matter in posterior hippocampus due to learning induced changes of "The Knowledge" exam testing their recall, there was a positive correlation between the changes and time as taxi driver, this demonstrates interaction between Nativist and Empiricists and 2 influences cannot be separated