1
Criminal Psychology
- Specialist area of psychology that addresses wide range of topics e.g. understanding
antisocial behaviour and what factors contribute to such behaviour
- This knowledge is then used in a variety of settings, including assisting the police to gain
information from witnesses, within the courtroom and after sentencing to treat offenders
- Helps to understand antisocial behaviour and those who commit it which helps to reduce
this behaviour
Introduction:
- Crime and Disorder Act (1998) defines anti-social behaviour as ‘acting in a way that caused
or is likely to cause harassment, alarm or distress to one or more people not of the same
household as the person acting in this way’
- Behaviours that are considered anti-social - being drunk, excessively noisy, criminal
damage, taking drugs and intimidating others
- Psychologists seek to explain antisocial behaviour through biological and social factors
- These factors are not causal so won’t definitely makes the person act in a
criminal/antisocial way
6.1 Content
6.1.1 Biological Explanations
Brain Injury
- May be caused by an accident, illness, drug/alcohol use
- ‘Traumatic’ brain injury occurs though direct damage to the brain such as a car accident or
being injured or assaulted in the head
- Alcohol has a toxic effect on the CNS and interferes with the absorption of vitamin B1
which is an important brain nutrient
- Being intoxicated impairs balance and decision making, thus can contribute to falls or
accidents that may injure the brain
- Personality may change as a result of brain injury or the person may behave in a way that is
untypical of them pre-trauma, e.g. Phineas Gage
- These behaviours may involve aggression or being reckless
- Williams et al (2010) found 60% of the 196 prisoners investigated received some sort of
brain injury
- Noted that adults with traumatic brain injury were relatively younger at entry into the
prison system than those without brain injury and reported higher rates of reoffending
- These injuries lead to a lack of development of temperance, social judgement and control
of impulses
- Risk taking behaviours and control impulses were also found to be more common
- These behaviours are directly associated with criminality
Evaluation
- When reviewing influence of brain injury on criminal behaviour, other comorbid conditions
should be mentioned
- E.g. many offenders often have history of substance misuse, may have been exposed to
violence as a child
,2
- These factors are known to increase criminal behaviour
- Therefore, difficult to establish a cause and effect relationship between brain injury and
criminal/aggressive behaviour because of these other factors may be involved
- Highlighted by Kreutzer et al (1991) - unable to prove or disprove a cause and effect
between traumatic brain injury and violence
- Out of 74 patients, 20% had been arrested pre-injury and 10% post
- Substance abuse, traumatic brain injury and crime interconnected (most arrests occurred
after use of alcohol or other drugs)
- The study concluded that criminal behaviour may be a result of post-injury changes leading
to poor judgment
- Further research by Kreutzer (1995) suggests that without the presence of substance abuse
history, brain damage was not a risk factor for criminal behaviour
The Amygdala and its Relation to Brain Injury
- Controls human emotions, therefore damage to this part of brain may result in problems
with how people express themselves
- Damage may also increase impulsiveness or irritability and aggression
- E.g. may have excessive reactions to their emotions because they cannot control them
- Pardini et al 2014 - individuals with smaller amygdale three times more likely to exhibit
aggression, violence and psychopathic features 3 years later
- Thus suggesting amygdala size can predict violence
- Cannon and Britton (1925) - carried out a sham rage study by severing neural connections
to the cortex of cats
- Sham Rage - an emotional state found in animals
- When provoked, cats exhibited emotional behaviour associated with rage and aggression
- Further research revealed that source of the rage came from the temporal reg ion,
specifically the amygdala
- When amygdala removed, animals became more placid - if stimulated, aggression
displayed
- Shows that amygdala has an important role in production of hostile behaviour
- Bard (1940) and Swantje et al (2012) - support idea that the amygdala plays an important
role in aggression but extrapolating animal research to humans is problematic in that it is
difficult to generalise - e.g. the prefrontal cortex in animals is smaller
- Raine et al (1997) - Significant brain differences were shown between the brain structure
(particularly the amygdala) of murders and control conditions
- A total of 41 NGRIs with a range of mental illnesses were studied using a PET scanner after
completing a continuous performance task
- Results showed lower glucose levels in the prefrontal cortex, which had previously been
linked to impulsivity
- The amygdala and hippocampus, which are responsible for learning also showed abnormal
functioning, explaining why the NGRI participants had all committed murder
,3
Evaluation:
- ‘Sham rage’ studies conducted on animals can be critiqued for lacking generalisability to
humans
- Animals do not have the capacity to inhibit their aggression with higher order thinking, thus
sham rage studies only apply to animals
- However, Narabayashi et al (1963) conducted psychosurgery on human patients with
aggressive behaviour by severing the amygdala from the limbic system and found a mood
stabilising effect in most patients (but not all)
- Demonstrates that not everyone with specific brain structures, who have these
abnormalities will become aggressive leading to the assumption that other factors must be
evident
- Robert Hare wrote book ‘Snake in Suits; When Psychopaths go to Work.’
- Highlighted how psychopaths are not just found amongst a criminal population; some traits
such as callousness and a lack of empathy arguable make individuals suitable for high level
management positions
XYY Syndrome
- Men have sex chromosomes XY and are governed by androgens, e.g. testosterone
- Females have sex chromosomes XX that are governed by oestrogen
- XYY syndrome occurs when some males are born with an extra Y chromosome
- It is a genetic condition whereby these males have a total of 47 chromosomes
- Occurs in 1 out of 1000 male births
- It is not inherited and randomly occurs at the time of conception
- Most boys with XYY have a normal development, although some boys will grow faster and
taller than usual
- However, some studies have shown a lower than average intelligence level and some may
display problems with behaviour and be easily distracted
- Has been thought to make men overly aggressive and lack empathy leading to it being
known as ‘super-male’ syndrome
Evaluation:
- Not likely to know true extent of the prevalence of XYY due to practicality of looking at
genetics of all male offenders to determine if they are XYY
- This requires skilled staff and is resource intensive
- That said, Theilgaard study does show a small presence of XYY men among a criminal
population, although it cannot be the only reason for criminal behaviour - if so, the rate of
XYY would be 100%
- She found that men with XYY were found to have lower levels of intelligence, therefore the
higher than expected number of XYY men in the offender population may be a
consequence of the learning difficulties associated with the condition rather than XYY itself
- Women also engage in criminal behaviour, yet XYY fails to account for this amongst women
- Mednick 1988 conducted a study of over 31,000 men and found no strong correlation
between the presence of an extra Y chromosome and criminality
, 4
Other Genetic Explanations for Criminality
- Twin studies - MZ twins share all genetic information, whilst DZ twins share 50%
- If MZ twins are more alike in terms of aggressive behaviour than DZ twins, this could be
due to genes rather than environment
- Slutske et al (1997) shown there is higher incidence of conduct disorder in twins when
compared to singletons
- One problem with twin studies is that they will often be brought up together in a similar
way so hard to say whether the concordance rates are caused by genetic or environmental
factors
- Adoption studies - Hutchings and Mednick (1997) studied male adoptees and discovered
that 85.7% of the males with a criminal record had a birth father with one too
- That said, also noted that male adoptees without a criminal record had a criminal father
31.1% of the time
- This does suggest a link between criminal behaviours and genetics
Personality
- Eysenck is 1 of the key theorists who has looked at personality traits; our enduring
characteristic that make us who we are and that influence our decisions and behaviour
- Examined following dimensions; extraversion (E), introversion (I), neuroticism (N), stability
(S) and psychoticism (P) suggesting that these dimensions relate to the underlying
functioning of the individuals nervous system
- These dimensions influenced by biology could explain criminality, known as the PEN
personality
- Extraversion - outgoing behaviour, e.g. want excitement, easily bored
- Introversion - reserved and reflective, prefer solitary
- Neuroticism - emotional instability, associated with anxiety, fear, depression and envy
- Stability - emotionally calm people who are unreactive and worried
- Psychoticism - individuals lack empathy, are aggressive, impersonal and cold
- Eysenck (1990) proposed the arousal theory to explain the causal roots of the three
dimensions personality
- Concept suggests that individuals are motivated to act in a certain way to maintain level of
physiological arousal
- When arousal levels drop below our personal optimal level, we engage in stimulating
behaviour to increase arousal
- Explained extraversion in terms of cortical arousal via the ascending reticular activating
system (ARAS) in the brain
- ARAS system transmits messages to limbic system, triggering the release of hormones and
neurotransmitters
- Introverts require less external stimulation or arousal explaining how they are less outgoing
and risk-taking whereas extraverts require greater amounts of external stimulation as they
have an under-active ARAS
Criminal Psychology
- Specialist area of psychology that addresses wide range of topics e.g. understanding
antisocial behaviour and what factors contribute to such behaviour
- This knowledge is then used in a variety of settings, including assisting the police to gain
information from witnesses, within the courtroom and after sentencing to treat offenders
- Helps to understand antisocial behaviour and those who commit it which helps to reduce
this behaviour
Introduction:
- Crime and Disorder Act (1998) defines anti-social behaviour as ‘acting in a way that caused
or is likely to cause harassment, alarm or distress to one or more people not of the same
household as the person acting in this way’
- Behaviours that are considered anti-social - being drunk, excessively noisy, criminal
damage, taking drugs and intimidating others
- Psychologists seek to explain antisocial behaviour through biological and social factors
- These factors are not causal so won’t definitely makes the person act in a
criminal/antisocial way
6.1 Content
6.1.1 Biological Explanations
Brain Injury
- May be caused by an accident, illness, drug/alcohol use
- ‘Traumatic’ brain injury occurs though direct damage to the brain such as a car accident or
being injured or assaulted in the head
- Alcohol has a toxic effect on the CNS and interferes with the absorption of vitamin B1
which is an important brain nutrient
- Being intoxicated impairs balance and decision making, thus can contribute to falls or
accidents that may injure the brain
- Personality may change as a result of brain injury or the person may behave in a way that is
untypical of them pre-trauma, e.g. Phineas Gage
- These behaviours may involve aggression or being reckless
- Williams et al (2010) found 60% of the 196 prisoners investigated received some sort of
brain injury
- Noted that adults with traumatic brain injury were relatively younger at entry into the
prison system than those without brain injury and reported higher rates of reoffending
- These injuries lead to a lack of development of temperance, social judgement and control
of impulses
- Risk taking behaviours and control impulses were also found to be more common
- These behaviours are directly associated with criminality
Evaluation
- When reviewing influence of brain injury on criminal behaviour, other comorbid conditions
should be mentioned
- E.g. many offenders often have history of substance misuse, may have been exposed to
violence as a child
,2
- These factors are known to increase criminal behaviour
- Therefore, difficult to establish a cause and effect relationship between brain injury and
criminal/aggressive behaviour because of these other factors may be involved
- Highlighted by Kreutzer et al (1991) - unable to prove or disprove a cause and effect
between traumatic brain injury and violence
- Out of 74 patients, 20% had been arrested pre-injury and 10% post
- Substance abuse, traumatic brain injury and crime interconnected (most arrests occurred
after use of alcohol or other drugs)
- The study concluded that criminal behaviour may be a result of post-injury changes leading
to poor judgment
- Further research by Kreutzer (1995) suggests that without the presence of substance abuse
history, brain damage was not a risk factor for criminal behaviour
The Amygdala and its Relation to Brain Injury
- Controls human emotions, therefore damage to this part of brain may result in problems
with how people express themselves
- Damage may also increase impulsiveness or irritability and aggression
- E.g. may have excessive reactions to their emotions because they cannot control them
- Pardini et al 2014 - individuals with smaller amygdale three times more likely to exhibit
aggression, violence and psychopathic features 3 years later
- Thus suggesting amygdala size can predict violence
- Cannon and Britton (1925) - carried out a sham rage study by severing neural connections
to the cortex of cats
- Sham Rage - an emotional state found in animals
- When provoked, cats exhibited emotional behaviour associated with rage and aggression
- Further research revealed that source of the rage came from the temporal reg ion,
specifically the amygdala
- When amygdala removed, animals became more placid - if stimulated, aggression
displayed
- Shows that amygdala has an important role in production of hostile behaviour
- Bard (1940) and Swantje et al (2012) - support idea that the amygdala plays an important
role in aggression but extrapolating animal research to humans is problematic in that it is
difficult to generalise - e.g. the prefrontal cortex in animals is smaller
- Raine et al (1997) - Significant brain differences were shown between the brain structure
(particularly the amygdala) of murders and control conditions
- A total of 41 NGRIs with a range of mental illnesses were studied using a PET scanner after
completing a continuous performance task
- Results showed lower glucose levels in the prefrontal cortex, which had previously been
linked to impulsivity
- The amygdala and hippocampus, which are responsible for learning also showed abnormal
functioning, explaining why the NGRI participants had all committed murder
,3
Evaluation:
- ‘Sham rage’ studies conducted on animals can be critiqued for lacking generalisability to
humans
- Animals do not have the capacity to inhibit their aggression with higher order thinking, thus
sham rage studies only apply to animals
- However, Narabayashi et al (1963) conducted psychosurgery on human patients with
aggressive behaviour by severing the amygdala from the limbic system and found a mood
stabilising effect in most patients (but not all)
- Demonstrates that not everyone with specific brain structures, who have these
abnormalities will become aggressive leading to the assumption that other factors must be
evident
- Robert Hare wrote book ‘Snake in Suits; When Psychopaths go to Work.’
- Highlighted how psychopaths are not just found amongst a criminal population; some traits
such as callousness and a lack of empathy arguable make individuals suitable for high level
management positions
XYY Syndrome
- Men have sex chromosomes XY and are governed by androgens, e.g. testosterone
- Females have sex chromosomes XX that are governed by oestrogen
- XYY syndrome occurs when some males are born with an extra Y chromosome
- It is a genetic condition whereby these males have a total of 47 chromosomes
- Occurs in 1 out of 1000 male births
- It is not inherited and randomly occurs at the time of conception
- Most boys with XYY have a normal development, although some boys will grow faster and
taller than usual
- However, some studies have shown a lower than average intelligence level and some may
display problems with behaviour and be easily distracted
- Has been thought to make men overly aggressive and lack empathy leading to it being
known as ‘super-male’ syndrome
Evaluation:
- Not likely to know true extent of the prevalence of XYY due to practicality of looking at
genetics of all male offenders to determine if they are XYY
- This requires skilled staff and is resource intensive
- That said, Theilgaard study does show a small presence of XYY men among a criminal
population, although it cannot be the only reason for criminal behaviour - if so, the rate of
XYY would be 100%
- She found that men with XYY were found to have lower levels of intelligence, therefore the
higher than expected number of XYY men in the offender population may be a
consequence of the learning difficulties associated with the condition rather than XYY itself
- Women also engage in criminal behaviour, yet XYY fails to account for this amongst women
- Mednick 1988 conducted a study of over 31,000 men and found no strong correlation
between the presence of an extra Y chromosome and criminality
, 4
Other Genetic Explanations for Criminality
- Twin studies - MZ twins share all genetic information, whilst DZ twins share 50%
- If MZ twins are more alike in terms of aggressive behaviour than DZ twins, this could be
due to genes rather than environment
- Slutske et al (1997) shown there is higher incidence of conduct disorder in twins when
compared to singletons
- One problem with twin studies is that they will often be brought up together in a similar
way so hard to say whether the concordance rates are caused by genetic or environmental
factors
- Adoption studies - Hutchings and Mednick (1997) studied male adoptees and discovered
that 85.7% of the males with a criminal record had a birth father with one too
- That said, also noted that male adoptees without a criminal record had a criminal father
31.1% of the time
- This does suggest a link between criminal behaviours and genetics
Personality
- Eysenck is 1 of the key theorists who has looked at personality traits; our enduring
characteristic that make us who we are and that influence our decisions and behaviour
- Examined following dimensions; extraversion (E), introversion (I), neuroticism (N), stability
(S) and psychoticism (P) suggesting that these dimensions relate to the underlying
functioning of the individuals nervous system
- These dimensions influenced by biology could explain criminality, known as the PEN
personality
- Extraversion - outgoing behaviour, e.g. want excitement, easily bored
- Introversion - reserved and reflective, prefer solitary
- Neuroticism - emotional instability, associated with anxiety, fear, depression and envy
- Stability - emotionally calm people who are unreactive and worried
- Psychoticism - individuals lack empathy, are aggressive, impersonal and cold
- Eysenck (1990) proposed the arousal theory to explain the causal roots of the three
dimensions personality
- Concept suggests that individuals are motivated to act in a certain way to maintain level of
physiological arousal
- When arousal levels drop below our personal optimal level, we engage in stimulating
behaviour to increase arousal
- Explained extraversion in terms of cortical arousal via the ascending reticular activating
system (ARAS) in the brain
- ARAS system transmits messages to limbic system, triggering the release of hormones and
neurotransmitters
- Introverts require less external stimulation or arousal explaining how they are less outgoing
and risk-taking whereas extraverts require greater amounts of external stimulation as they
have an under-active ARAS
