biological explanations of criminal behaviour Flashcards
2 explanations ?
- inherited criminality
- the role of the amygdala
4 explanations for inherited criminality ?
- diathesis stress model
- twin studies
- MAOA gene
- differences in the brain
diathesis stress model ?
this theory suggests that some people inherit genes that, under certain environmental conditions will influence them to have in a criminal way.
- for example, it may be someone who has a gene for impulsivity thus making them fearless and more likely to commit crime this is known as a diathesis stress model
twin studies ?
this argues that there’s genes in individuals that are predisposed to criminal behaviour. the evidence for this genetic component comes from twin studies where identical and non identical twins were compared.
- a meta analysis by raine reviewed research on the delinquent behaviour of twins and found the average concordance rate was higher for MZ twins (52%) than DZ twins (21%)
MAOA gene ?
if there’s a genetic bases for criminal behaviour the gene would have some sort of effect on the body which would lead to behaviour such as impulsiveness or aggression. One gene in particular interest is the MAOA gene which helps recycle serotonin and dopamine.
- brunner et al studied a dutch family who were highly aggressive, the behaviour was linked to a mutation in the MAOA gene meaning they had abnormally low levels of serotonin which may predispose individuals to impulsive and aggressive behaviour
differences in the brain ?
the criminal gene may cause difference in areas of the brain or differences in key neurotransmitters. Raine reviewed 71 brain imaging studies showing that murders , psychopaths and violent criminals have reduced functioning in the prefrontal cortex that part of the brain that is responsible for regulating emotions, controlling behaviour and moral behaviour. lower activity in this area is associated with impulsiveness and loss of control.
evaluation pints for inherited criminality?
- research support
- evaluation of twin studies
- environmental triggers
research support - inherited criminality?
- lots of research that can be used to suggest criminality is due to genetics
- raine = MZ DZ twins, the closer our genetic makeup the more likely we will share the same behaviour
- brunner = dutch family, low levels of serotonin, predisposed to impulsive and aggressive behaviour proving criminal behaviour can be hereditary
-raine - 71 brain imaging studies, supports brain differences can also explain criminal behaviour due to criminal gene - criminal behaviour is a result of innate influences
evaluation of twin studies ?
- cannot fully rule out nurture
- cordage rates of MZ could be more similar because their environment may be more similar as they look the same and may get treated the same, environment influence may lead them to act similar
- however, studies of adopted children support the findings, mednick found a significant relationship between the adoptee and their biological parent for criminal behaviour but no relationship the adoptee and their adopted fathers in terms of criminal convictions. this suggests that nature is more important for criminal behaviour than nurture
- however it could be argued that we also should consider the roles of nurture as it also plays a role in behaviour.
environmental triggers ?
- environmental triggers play a huge role in criminal behaviour especially those who carry a criminal gene
- twin studies show while there is a genetic element the environment also plays a role, dalgard and kringlen found no statistically significant concordance rate in MZ twins for a broad definition of crime.
- research suggests that both nature and nurture contribute to criminal behaviour while we may inherit a gene such as MAOA low activity that predisposes us to act in a criminal way, we need an environmental trigger for us to deepen antisocial and possible criminal behaviour.
- suggests that’s some individuals are genetically predisposed to commit crime however it’s the environment we are around that determines whether the genes are triggered
what are the 2 types of aggressive behaviours that psychologists believe in ?
- proactive - planned and premeditated aggression
- reactive aggression - angry, heated spur of the moment emotional aggression
why is the amygdala of interest ?
it is one of the neurological structures in the brain that seemed to be heavily involved in aggression
3 areas that are important in the amygdala ?
- structure and functioning
- aggression
- fear conditioning
what is the amygdala ?
structure in the brain, we have 2 amygdale one for each hemisphere int he brain. each is located close to the hippocampus.
what is the role of the amygdala ?
essential to your ability to feel certain emotions and perceive them in other people lex this includes fear and the many changes that it causes in the body, such as heart pounding in the body.
research support for the role of the amygdala ?
pardini conducted a longitudinal study of a sample of 503 children over 6/7 years, every 6 years measured their anti social behaviour. when they were 25 the researchers measured the amygdala volume of 56 of the original PT who represented different levels of antisocial behaviour
- the found men with lower amygdala volume exhibited higher levels of aggression and psychopathic features from childhood to adulthood
- supports the link between amygdala volume and violent criminal behaviour it is also important because it cannot be explained by protection confounding variables such as IQ and race.
environmental triggers ?
- play a huge role in criminal behaviour especially with those who carry a criminal gene
