Biological explanations of offending behaviour Flashcards
What are the genetic explanations?
-Monoamine oxidase A gene
-Genetic Transmission
What is the explanation of the monoamine oxidase A gene?
-one example of a gene linked to crime is is the MAOA gene (located on the X chromosome).
-The low variant of this gene causes a deficiency in monoamine oxidase A (MAOA).
-Monoamine oxidase A is an enzyme that breaks down important neurotransmitters in the brain, including dopamine and noradrenaline which has links to aggression which may lead to offending behaviour.
There are variations of the gene found in humans and these result in different levels of enzymatic activity
what happens to people with the low activity form of MAOA-L?
-produce less of the MAOA enzyme
-so he have found a correlation between the low activity form of MAOA and aggression
What do genetic explanations for about offenders?
Then inherit a gene or combination of genes that predispose them to commit crime
How do twin studies identify a genetic basis of behaviour?
MZ twins and DZ are twins are compared and if the MZ twins has a higher concordance rate than the DZ twins it is assumed that genetic factors are involved in offending behaviour
what have normal explanations for offending behaviour been proposed for?
Both possible differences in brain structure and the biochemistry of the body
what is suggested that aggression is the result of?
an interaction between a system of brain structures- offending behaviour has been frequently linked to aggression
what does the limbic system (which includes the amygdala) do?
It processes emotional information
why is the amygdala implicated in offending g behaviour?
-aggressive impulses are created in the amygdala in responding to a threat in the environment
What is the amygdala involved in?
our stress response therefore when activated it can initiate the process of fight or flight
What does the prefrontal cortex do?
Regulates impulse control and social reactions
What has damage to the prefrontal cortex being associated with?
anti social behaviour and offending behaviour
what did research by Kandel and Freed (1989) find?
that participants with antisocial behaviour and frontal lobe damage showed the tendency to demonstrate emotional instability and the failure to consider the consequences of actions
What would the traits of people with anti-social behaviour and frontal lobe damage be a result of?
impaired function in the functional roles region responsible for planning behaviour
What have the irregularities in the levels of neurotransmitter has been linked to?
Violence and offending behaviour
What does serotonin do and what does this mean?
-regulates mood and impulse control.
-means that in low levels it could
be implicated in offending behaviour as there will be more impulsivity.
-If a situation is particularly emotional then someone with low levels of serotonin could easily react as they have an impaired capacity to hold back
what have abnormally high levels of noadrenaline been associated with?
aggression, violence and criminality. High levels of noradrenaline are associated with the activation of the sympathetic branch of the autonomous nervous system, and the fight or flight response.
What does the fight or flight response do?
helps in a threatening situation and
thus is linked with aggression, and so as a consequence, it is easy to explain some crimes as possibly being underpinned by the chemical imbalance of noradrenaline.
What did lombroso propose?
One of the earliest theories of criminology which claimed that criminality was heritable and that criminals were genetic throwbacks who had distinguishing features which originated from a more primitive stage development. (lombroso called these features atavistic).
what did Lombroso do and what did he find?
-examined the features and measurements of nearly 4,000 criminals, as well as the skulls of 400 dead criminals.
-common findings from Lombroso’s investigation included large heavy brow and sloping foreheads, large strong jaw, darker skin, large ears
and long ape-like arms
what did Lombroso conclude?
-these characteristics indicated that such people were lacking evolutionary development, as their untamed nature meant that they would find it impossible to adjust to the demands of civilised society and would eventually turn to crime.
-he went on to say that such individuals were therefore not responsible for their actions as they could not be blamed for their innate, inherited physiology.
What did Lombroso later do?
went on to categorise particular types of criminals in terms of their
physical features and characteristics.
what were murderers described as?
described as having a beak like nose, bloodshot eyes and curly hair
what were sexual offenders described as?
described as having projecting ears and swollen, fleshy lips.
what are fraudsters described as?
described as having lips that were thin and ‘reedy.’
