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Biological theories of criminality - Coggle Diagram
Biological theories of criminality
Lombroso's theory 'born criminals'
What are some features of a criminal according to Lombroso?
enormous jaw
high cheeckbones
handle shaped ears
large eye sockets
From his research Lombroso claimed that criminals could be identified by their distinctive facial features and also that different types of criminals have different facial features e.g. murderers had aquiline noses whereas thieves had flattened noses
What is meant by atavism?
throwback to an earlier, primitive stage of evolution - Lombroso claimed that in a more primitive society they would be seen as normal but in a modern society they were abnormal
Why did Lombroso label criminals as savages?
because they were presocial and unable to control their impulses and had reduced sensitivity to pain (hence why they often had tattoos
Why did Lombroso think people were born criminals?
because they could be identified scientifically by reading their bodies for the physical characteristics that marked them out as different
What other two types of criminals did Lombroso identify?
insane criminals
epileptic criminals
he also identified criminaloids whose criminality was caused by environmental factors rather than biology
Sheldon's somatotype theory
Sheldon viewed criminals as physically different from non criminals. in his view certain somatotypes (body types) are linked to criminal behaviour
what are the three somatotypes identified by sheldon?
endomorphs
rounded, soft, tending to fat, lacking muscle or tone, wide hips
sociable, relaxed, comfortable and outgoing
ectomorphs
thin, fragile, lacking both fat and muscle, flat chested, narrow hips and shoulders, thin face, high forehead
self conscious, fragile, inward looking, emotionally restrained and thoughtful
mesomorphs
muscular, hard bodied, very little fat, strong limbs, broad shoulders, narrow waist
adventurous, sensation seeking, assertive, domineering, enjoy physical activity
According to Sheldon which somatotype is most likely to commit crime and why?
mesomorphs
they are more likely to be attracted to the risk taking and their physique and assertiveness can be important assets to crime
Twin studies
genetic theories explain that crime runs in families
this is because they are blood relatives so if one member has a criminal gene it is likely that relative will also have that same gene
twins are used to test genetic theories
this is because identical and monozygotic twins share exactly the same genes because they both developed from the same fertilized egg. this means that if one twin is criminal so should the other
Christiansen twin study in Denmark
study of 3586 twin pairs
found that there was a 52% concordance rate between MZ twins but among non identical twins
Ishikawa and Raine
they found a 44%concordance rate for identical twins but only 21.6% for non identical twins
Adoption studies
these compare adopted children to both their biological birth parents and to their adopted parent
the adopted child, especially if adopted soon after birth, shares the same environment as their adopted parent but the same genes as the biological parent, therefore it can be measured whether criminality is genetic or due to the environment.
if it is found that the person who was adopted in regard to criminality is more similar to their birth parents behaviour this would support the genetic explanation
Mednick et al
examined data on over 14000 adopted sons in denmark from 1924-1947 and found that sons were more likely to have a criminal record if birth parents also had one, concordance rate of 20%, therefore supporting the genetic explanation
found a smaller proportion, 14.7% had a criminal record if their adoptive parent had one.
Jacobs XYY
what are chromosomes?
made up of DNA and protein, they are found in the nucleus of our cells. each chromosome contains many genes so carry all the genetic information that we inherit from our parents
how many chromosomes do humans normally have?
46 chromosomes, 23 pairs
what are the sex hormones of males and females?
males
XY - one from each parent
females
XX - one from each parent
what is super male syndrome?
sometimes abnormalities occur for example males may have a extra Y chromosome so therefore they have what is known as XYY syndrome (super male syndrome)
males with this tend to be
tall
well built
more aggressive and violent
of low intelligence
evidence of how does this cause criminality
studies on imprisoned criminals such as those in psychiatric hospitals show that a higher than average proportion of inmates were found to have XYY, many with histories of aggression and violent assult
Brain injuries
Phineas Gage
Diseases
in the 1920's encephalitis lethargica among children was linked to criminality as it was thought to cause destructiveness, impulsiveness, arson and abnormal behaviour
other diseases that have been linked to criminality
senile dementia
brain tumours
hunters chorea
brainwave activity is measured by an electroencephalograph (EEG)
criminals that have been found to have abnormal brainwave activity are usually clearly insane murders and psychopathic criminals
Sex hormones
testosterone
if there is a overproduction or underproduction of the hormone there may be emotional disturbances as testosterone makes males typically more aggressive than females as they have a higher level. it has been linked to crimes such as rape and murder
some men take additional testosterone to help them body build but can also have effects such as extra hair and also suppresses the immune system so they are more likely to die of infectious diseases
Steve Jones states that men are 10x more likely to commit murder than women - gets rid of the male opposition to impress women
premenstrual tension (PMT), postnatal depression and lactation
these have all been accepted as partial defences on the grounds that the hormones involved affected the defendants judgement, mood or self control
Substance abuse
this involves the intake of drugs and other substances
some are legal e.g. alcohol and glues or medically prescribed e.g barbiturates
some are illegal e.g cannabis, MDMA,LSD, heroin and cocaine
saunders found that alcohol played a role in about 1000 arrests per day
cocaine and crack are closely linked to violence whereas cannabis, heroin and MDMA tend to reduce aggression
Blood sugar levels
hypoglycaemia (low blood sugars)
can trigger aggressive reactions
studies show a link between low blood sugar and alcohol abuse - drinking large quantities of alcohol can induce hypoglycemia and increase agression
schoenthaler claims that by lowering the daily sucrose intake of young offenders he could reduce the levels of antisocial behaviour
Other substances
food additives and diet
synthetic food colouring tartrazine have been linked with hyperactivity
lead pollution
lead is linked with hyperactivity
allergens
vitamin deficiencies
vitamin B deficiency has been linked to erratic and aggressive behaviour
serotonin
serotonin is known as the happy chemical as it appears to play a role in regulating mood and low levels have been associated with depression as well as other mental health disorders such as anxiety or OCD
serotonin is a hormone and neurotransmitter (chemical messengers that transmit messages between nerve cells or a nerve cell and another target cell)
serotonin is a precursor to melatonin which is a chemical that regulates the bodies sleep and wake cycle
tryptophan, a serotonin precursor, is an essential amino acid that is important in the production of serotonin. tryptophan is contained within eggs, nuts, seeds and cheese