forensics - genetical and neural explanations Flashcards
who did researchers of neural explanations for criminality specifically look at?
sufferers of anti-social personality disorder
what is APD?
anti-social personality disorder - reduced emotion, impulsive and lack of empathy
function of prefrontal cortex
regulates emotional behaviour
how has activity in the prefrontal cortex been linked to criminality
brain scans have shown that criminals have reduced activity in the prefrontal cortex
what did Raine find?
11% reduction in the volume of grey matter in the prefrontal cortex of people with APD vs people without
what are mirror neurons?
Mirror neurons are a type of brain cell that allow us to understand peoples emotions and actions. Even allowing us to stimulate an appropriate response to a persons actions.
you dont have to think about what a persons actions mean you just know effortlessly because of these neurons.
how are mirror neurons involved in empathy?
mirror neurons are involved in social cognition allowing us to interpret intention and emotion in others allowing u to empathies
how do people with APD experience empathy
sporadically - it is like a switch tha turns on and off
what did keysers find?
only when offenders were asked to empathize they did, empathy only took place when activated by mirror neurons. This suggests they have a switch between empathy states when ‘normal’ brain is always on.
evaluate neural explanation of offending behaviour
- keysers
- raine
- biologically reductionist
- alternative explanations
what does genetical explanation suggest?
criminal behaviour is predisposed by genes
what are twin studies?
look at concordance rates between MZ AND DZ
what is an adoption study?
adoption studies look at the adopted childs behaviour and see if it is similar to their biological parents. If it is this suggests a genetical influence because they are not in the same environment as them.
what was crhristiansons research?
found concordance rates of 33% for MZ and 12% for DZ in offending behaviour
what was tiihonen research?
analysed 900 offenders jeans and found that 2 had abnormalities involved in crime
what genes are in crime?
MAOA
CDH13
what is the MAOA gene?
controls serotnin and dopamine and has been lined to agressive behaviour
what is CDH13 gene?
associated with substance abuse and ADHD
how do male and female MAOA genes differ?
males have one whilst women have two
why does the MAOA gene make sense?
Because males are more likely to commit crime because they less MAOA genes and are more agressive
what is the diathesis stress model?
it acknowledges that whilst crime has a biological disposition the enviroment also has a as a role in criminal behaviour.
crime is biology + psychology/enviromental trigger
example of trigger for crime
criminal role models or dysfunctional family
what was mednicks research?
police records of 13,000 danish adoptees
13.5% crime with no parents criminal
20% when biological criminal
24% when adoptive and biological criminal
supports diathese stress model
what are the problems with twin studies?
usually small sample
also unsual in themselves cannnot be generalised
most twins in the same enviroment
may act as a confoudning variable AS CONCORDANCE RATES MY BE A RESULT PF SHARED EXPERIENCES RATHER THAN GENETICS
problems with adoption studies?
lack of control
late adoption, still contact with biological family
hard to know how much effect effect the biological family had
cannot be sure genetics is the case not valid,
WHO FOUND THAT MAOA AAND CDH13 GENE MAY BE ASSOCIATED WITH CRIME?
TIIHONEN.
what was Tiihonens research?
- genetic analysis of around 900 offenders
- abnormalaties with the genes maoa and cdh13
- offenders with this high risk genetic combination were 13x more likeley to have a history of violent behaviour
summary AO1 of genetic explanation for crime
1) twin studies - Christianson
2) adoption studies
3) Candidate genes - Tiihonen
4) Diatheses stress model
evaluate genetical explanations
- research support from Christianson
- problems with twin studies - cant completely separate
- reductionist
- alternative explanation
what are family studies?
are studies of whether a disease or trait “runs in a family”. In other words, they are studies aimed at detecting if having a family history of a certain behaviour or illness is associated with greater risk.
