nature vs nurture

• main question?

  • what is the relative contribution of nature/nurture on human behaviour?
• define nativism?

  • describes stance that agrees with nature side of debate
• define nativists?

  • suggest we are born with pre-disposition & pre-programmed behaviours - innaate
• nature side?

  • belief that behaviour is result of genes we inherit
  • heredity is more influentiral in determining behaviour
• example of nature stance?

  • biological explanation for aggression suggests high levels of testosterone plays role in cause of aggression
  • research has shown that when mice were castrated & testosterone decreased aggression also decreased
  • when testosterone later reinjected aggression increases
  • shows aggression has biological basis so is on nativist side as it shows behaviour is predetermined by our hormones so environment doesnt play role
• nurture side?

  • belief that behaviour is result of environmental (external) factors
  • assumes that environment & experience is more influential in behaviour
• define empiricism?

  • opposing extreme viewpoint suggesting we are born without any innate mechanisms
  • instead all we become is due to our experiences
  • we are born as blank slates & what we experience defines us as a person
• example of nurture stance?

  • learning approach to explaining phobias as it says environment causes our phobia due to associating frightening experience with stimulus & maintaining phobia through reinforcement
  • they claim that it has nothing to do with biology its purely down to environment
• relative importance of herdity & environment in determing behaviour?

  • nature-nurture is an impossible question to answer
  • environmental influence in childs life begins as soon as child is borm
  • so they are closely intertwined - difficult to separate 2
• twin studies?

  • one way of studying heredity
  • ocd - mz twins concordance rate is 87% whereas dz twins is 47%
  • behaviour is based on genetics as mz twins more genetically similar so more likely to suffer from ocd HOWEVER...
  • if it was purely down to genetics concordance rates for mz twins should be 100% showing that heredity & environment may affect behaviour
• interactionist approach?

  • suggests both genetics & environment play part in behaviour
  • suggests person may be genetically predisposed to certain behaviour/trait however its moderated by environment - may not suffer from it until triggered by factor in environment
• example of interactionist approach?

  • diathesis stress model - abnormality is caused by both biology & environment
  • sz - someone has genetic predisposition by having PCM1 gene/neural correlates but this can lay dormant & never be expressed until stressor in environment such as family dysfunction triggers development of sz
• evidence from gottesman - nature?

  • reviewed 40 twin studies & found 48% concordance for mz twins & 17% for dz twins for sz
  • suggests genetics do influence sz as those more genetically similar are more likely to have sz compared to those less genetically similar.
  • nature side is influential approach to behaviour as concordance rates of twins is evidnece that shows genetics play huge role in behaviour rather than nurture
• X problems with methodology?

  • most research to see whether nature/nurture is most important come from twin studies
  • problem is that it makes assumption that only difference between mz & dz twins is genetics
  • but parenting style differs for mz & dz twins - mz treated more similarly than dz as theyre identical
  • means difference between mz & dz twins concordance may not just be genetics & may be due to upbringing & environment.
  • cant be certain that behaviour is due to nature/nurture as both sides of argument may be needed not just 1
• * practical application - nurture?

  • empiricists argue that all behaviour is learnt through environment & experiences - reinforcements
  • if this is case can help in real world in prisons
  • token economy so that prisoners are rewarded through positive reinforcement so theyre more likely to repeat good behaviour & be rehabilitates
  • nurture side influential approach to behaviour as its helped in real world so must be accurate
• X better stance is appropriate?

  • nature side of debate - behaviour is purely due to biology & genetics
  • nuture side - all behaviour is learnt
  • but currently more popular & accurate stance is that behaviour is a result of both nature & nurture.
  • problem with nature/nurture debate is that interactionist approach may be more accurate as it takes into account both nature & nurture