Q1
20 marks
1 biological & 1 non-biological
Explain what is happening using different approaches and studies.
Strengths and weaknesses
Q2
20 marks
Treatment program to change future behaviour.
CBT, anger management, drug, diet.
Strengths and weaknesses
Q3
12 marks
Offender profiling
6 profiles
Question 1
Genetics
Sometimes a third chromosome is present in some of or all cells and this is referred to as trisomy.
Edward’s syndrome is a genetic disorder caused by having an extra chromosome 18 in some or all of
their cells. Edward’s syndrome is marked by a low birth weight and certain abnormal features.
Down syndrome is a genetic disorder caused by having an extra chromosome 21 in some or all of
their cells. People with down syndrome typically have a lower IQ, are slower to speak than other
children and have distinct physical traits.
Patau syndrome is a genetic disorder caused by having an extra chromosome 13 in some or all of
their cells. Symptoms and features of Patau syndrome include a cleft lip and palate, abnormally small
eyes, absence of one or both eyes, reduced distance between the eyes, and problems with the
development of the nasal passage.
Chromosome 23 is the sex chromosome and determines if someone is assigned male (XY) or
assigned female (XX) at birth.
“Violent crime is more likely to be committed by XY than XX.”
Jacob’s syndrome is a genetic disorder that is not inherited and causes chromosome 23 to be XYY. 1
in 1000 men in the USA have Jacob’s syndrome. Symptoms include an above average height, lack of
empathy, increased aggression, acne, learning disabilities or a lower IQ, and behavioural issues (like
impulsivity). The additional Y chromosome causes heightened testosterone in men with Jacob’s
syndrome, causing these traits.
Prison study (Jacobs, 1965) – 1 in 28 of men in prison had XYY.
Court-Brown (1965) – 314 patients found to have XYY. Recommendation to keep them hospitalised
because of an increased risk in aggressive and criminal behaviour.
,Glass (1970) pushed for abortion laws to allow women to abort if genetic tests showed that the fetus
was XYY.
Stefan Kiszko – Wrongfully imprisoned for the murder and rape of an 11-year-old. He didn’t have a
lawyer and wasn’t asked if he wanted one. He spent 16 years in prison before being released and
died of a heart attack a year later. Because he had Jacob’s syndrome and had a lower IQ, he was
failed by the justice system.
Theilgaard (1984) wanted to know if there was a gene responsible for criminal behaviour. He
conducted the experiment on 30,000 men. 16 of the men had XXY and 12 had XYY. They performed
a personality test, which was compared to XY men, and also interviewed them about background
and criminal history. Theilgaard found that XYY men had slightly lowered intelligence and slightly
higher aggression compared to XY men.
Strengths:
- Large sample size of XY men means more reliable information.
- Bought in interviewers who didn’t know the aim of the study to interview the men, removes
researcher bias.
- Found a link between aggression and XYY.
- Lots of measures.
Weaknesses:
- Only 12 men were XYY.
- Focuses on correlation not causation.
- Theilgaard is looking for a criminal gene but is only looking at chromosome 23.
- There could be other reasons for aggression, i.e., media intake, childhood.
Explain what is meant by XYY syndrome. (4 marks)
XYY syndrome, also known as the supermale gene or Jacob’s syndrome, is an intersex identity in
which the 23rd chromosome pair, or the sex chromosome, has an additional Y. This results in increase
testosterone within men. Men with XYY are often above the average height, have increased acne or
acne scars, longer limbs, lower IQ or learning difficulties, and lack of empathy. In the 1960’s and 70’s,
there were studies conducted on XYY men to find out if there was a “criminal” gene, as it was
believed XYY men would be more violent than XY men due to their additional chromosome. 1 in
1000 men in the US have XYY. XYY syndrome is a chance mutation instead of being hereditary.
Explain the procedures and findings of Thielgaard’s research and give one strength and one
weakness of it. (6 marks)
Thielgaard’s sample size consisted of 30,000 men, 12 of which were XYY and 16 were XXY. He
conducted interviews, took blood tests, performed a personality test, investigated criminal and
childhood history, and compared the results of the XYY men to the XY men. The aim of the research
was to find out if there was a gene that caused aggression and criminal behaviour. They found that
the 12 XYY men had lower IQs and were more aggressive, and that XXY and XYY men were very
similar. A strength of this research is that, to remove researcher bias, Theilgaard brought in external
social worker to conduct the interviews, and this social worker did not know the aim of the research.
However, a weakness of the research is that only 12 of the 30,000 men had Jacob’s syndrome, which
means the results gathered from those 12 men are likely to be inaccurate.
The biological approach
, The biological approach focuses on genes, the brain, neurotransmitters, and hormones. It suggests
that evolution has a factor in phobias, and that phobias can be passed down from our ancestors,
which is why fears
% of DNA shared of heights, snakes,
and spiders are so
Grandparents common.
Half siblings Behavioural
characteristics are
Parents inherited the same
Siblings
way physical
characteristics are.
DZ Twins
MAOA gene
MZ Twins
The MAOA gene is
0 10 20 30 40 50 60 70 80 90 100responsible for
% of DNA shared MAOA enzyme
activity
(monoamine oxidase A). MAOA enzyme breaks down neurotransmitters like serotonin,
noradrenaline, and dopamine. MAOA is referred to as the warrior gene. MAOA-L produces low levels
of the MAOA enzyme and MAOA-H produces high levels of the MAOA enzyme. Dysfunction in MAOA
activity results in a dysfunction in serotonin levels
Serotonin
Serotonin is a chemical that carries messages between nerve cells in the brain and the rest of the
body. Serotonin plays a key role in body functionals such as mood, sleep, digestion, nausea, wound
healing, bone health, sexual desire, and blood clotting. A serotonin deficiency can cause depression
or OCD. Low serotonin also results in less control over emotional responses and an increase in
impulsivity.
Dopamine
Dopamine is a neurotransmitter made in the brain. It plays a role as a reward centre and in many
body functions such as attention, mood, motivation, movement, and memory. A dopamine
deficiency can cause schizophrenia, Parkinson’s disease, or ADHD.
Noradrenaline
Noradrenaline is both a hormone and a neurotransmitter which causes the fight or flight response.
Men with MAOA-L variation were found to be more violent and inflected the worst injuries on their
victims.
The MAOA gene was removed from some rats, and it was found that they became hyper aggressive.
This supports the role of MAOA on aggression.
