raine et al (biological)

• hypothesis

  "seriously violent individuals have localised brain damage in the pre-frontal cortex; the thalamus; the hippocampus and the amygdala"
• what type of hypothesis is it?

  one tailed
• what is the iv?

  the violent/ non-violent individual
• what is the dv?

  the measured brain damage
• how was the dv operationalised?

  the violence level or which parts of the brain are damaged
• background: brunner et al

  aim - study and understand the behaviour of males in a large family in the netherlands. the behaviour exhibited by the males in the family was borderline mental retardation, (their average IQ was around 85), and violent behaviour.

  examples:

  attemted rape

  exhibitionism

  arson

  impulsive aggression
• brunner et al : background study

  design - quasi - experiement, the males had a hereditary genetic disorder, Brunner couldn’t have manipulated the IV
• brunner et al : background

  participants - 5 males from family in netherlands, all have same genetic condition (Brunner Syndrome).

  2 carrier females, 1 non-carrier female (control)

  compared to 3 clinically affected males.

  women aren’t affected by the condition, they can carry the gene but don’t exhibit any symptoms
• brunner et al: background

  results: all males acted aggressively when angry, fearful or frustrated. a base change was identified in all 5 males. resulted in flawed monamine metabolism, linked with deficit in MAOA. males are affected because it’s specifically the single x chromosome which is responsible for the production of MAOA. Not all males in family were unable to control their aggression, even if they suffered mental retardation.
• brunner et al: background

  conclusions - its likely the deficit in the gene which causes flaws in serotonin metabolism is the cause of mental retardation thus aggressive behaviour exhibited in males.

  MAOA deficiency accounts for their inability to regulate their aggression.
• Evaluating brunner : background to raine (1)

  • rare condition - accounts for small sample and lack of generalisability.
  • study provides support for determinism argument (men in study all had a genetic condition - not learned, behaviour pre-determined by the condition) .
  • study is androcentric as its only experienced by males.
• evaluating brunner : background to raine (2)

  ethnocentric - however Brunner wanted to study a specific family with a rare condition

  reductionist - lack of other variables studied, given there were males that didn’t exhibit aggressive behaviour in family that weren’t studied, conclusions can be questioned.
• evaluating brunner: background study (3)

  methodology was scientific - no social desirability bias
• raine procedure

  study conducted on convicted murderers - all plead NGRI. all the murderers were brain scanned/ compared with a control group.
• raine results

  murderers had reduced activity in areas of the brain such as the pre-frontal cortex, thalamus, hippocampus, and the left side of the amygdala - which are all linked with violent behaviour
• raine aim

  to use a multi-factorial approach to understand antisocial and aggressive behaviour but primarily from a biological perspective
• raine design

  review article - review/ summary of a number of neuropsychological, neurological, and brain imaging studies, in order to understand the neurological basis for antisocial behaviour and children’s development.
• raine results (1)

  1. adolescent brain is still forming its final connections up to the early twenties
  2. a low resting heart rate may be a good predictor of individuals who will seek to raise their heart rate, via thrill seeking activities
• raine results (1)

  individuals may have an increased risk of having a biological predisposition to antisocial behaviour behaviour from the following factors:

  • birth complications
  • poor parents
  • physical abuse
  • malnutrition
  • smoking and drinking during pregnancy
• raine conclusion

  1. link between brain activity and a predisposition to violence.
• raine 1997

  participants - 41 murderers: 39 male ; 2 female. In california, USA. all NGRI. medication - free for 2 weeks because medication changes brain function
• raine 1997

  • 23 head injury’s
  • 6 schizophrenic
  • 3 drug abusers
  • 2 affective disorders
  • 2 epilepsy
  • 2 hyperactivity / learning
  • 2 personality disorders
• raine 1997 participants

  control group - 41 non-murderers , matched for age and sex , included 6 schizophrenics (medication-free for 2 weeks as a control)

  variables that weren’t controlled:

  • handedness
  • ethnicity
  • history of head injury (none of these variables showed difference)
• what debate is associated with Raine‘s study?

  socially sensitive research - has to be a quasi - experiment as it would be unethical otherwise.
• raine 1997 procedure (1)

  • pet scan used (pps injected with a radioactive chaser)
  • a continuous performance task was conducted for 32 minutes prior to the scan taking place
  • this activated the frontal lobe, the parietal lobe and the right temporal lobe
• raine 1997 procedure

  • pet scans show some of the differences in activation levels, depending on certain lifestyle choices.
  • the brighter the colours, the higher the level of activation. (e.g. non-smokers have higher activation)
• raine 1997 - parts of the brain

  frontal lobe affects: reasoning, morality, regulating emotions

  temporal lobe: understanding

  parietal lobe: comprehension, sense of time and space
• raine 1997 results (1)

  1. lower activity in cortical regions in murderers
  2. reduced activity in prefrontal and parietal lobes in murderers
  3. reduced function in corpus callosum in murderers ( two hemispheres aren’t communicating effectively - reduces reasoning skills and rationality)
• raine 1997 results (2)

  4. left hemisphere less active than right hemisphere in murderers (speech and language cognitions’ - misread/ misinterpret situations)

  5. amygdala and thalamus are asymmetrical in murderers ( reduced on left; greater on right) this could affect fight or flight response (strong fight response)
• biological strategy for preventing criminal behaviour

  chemical castration and/or surgical castration