AC2.1 Biological theories of crime

Question 1

What are monozygotic twins (MZs)?

Answer 1

These are identical twins, where single egg fertilised by single sperm, then splits in two
Mono means one
Zygote means egg
Share 100% of their DNA

Question 2

What are dizygotic twins (DZs)?

Answer 2

Non-identical (fraternal) twins from 2 eggs
Separate eggs fertilised by separate sperm
Share only half their genes
Di means two
Zygote means egg
Share 50% of their DNA

Question 3

What it concordance?

Answer 3

The level of relationship between two things

Question 4

Explain the XYY theory regarding genetic theories

Answer 4

Suggests that some crime might be attributable to a chromosomal abnormality
XYY men are seen as more aggressive and more inclined to violent behaviour

Question 5

Who suggested they men with XYY syndrome were more aggressive than normal XY men

Answer 5

Jacob er al. (1965)

Question 8

Explain Lange’s (1929) findings of the twin study

Answer 8

Found that:
MZs showed a higher rate of concordance than DZs for criminal behaviour
10/13 MZs had both went to prison
2/17 DZs had such concordance

Question 9

Explain adoption studies

Answer 9

The study looks at the impact of nurture in children who are raised by their non-biological parents

Question 10

Explain what Hunchings and Mednick’s (1975) study on 14,000 adopted children found

Answer 10

Found that a higher rate of boys with criminal convictions had biological parents with criminal convictions
Suggesting that there is a link between aggression and genetics

Question 11

What are physiological theories?

Answer 11

They focus on a person’s physical form as an indicator of criminality

Question 12

What did Lombroso argue?

Answer 12

He argued that the criminal are a separate species.
A ‘born criminal’ could be determined by the physical shape of the head and face, people who commit crimes had atavistic features

Question 13

Give some examples of atavistic features

Answer 13

Large or forward projection of the jaw 
High cheekbones 
Flattened or upturned nose 
Low sloping forehead 
Large ears

Question 14

What did Lombroso examine

Answer 14

He examined the facial and cranial features of 383 dead criminals and 3839 living ones
Found that 40% of criminal acts could be accounted for by atavistic characteristics

Question 15

What did Willian Sheldon propose?

Answer 15

Like Lombroso William proposed that criminal behaviour if linked to a persons physical appearance

Question 16

What are the three somatotypes?

Answer 16

1. Endomorph
2. Ectomorph
3. Mesomorph

Question 17

Describe endomorph

Answer 17

(Fat and soft) tend to be sociable and relaxed

Question 18

Describe ectomorph

Answer 18

(Thin and fragile) are introverted and restrained

Question 19

Describe mesomorph

Answer 19

(Muscular and hard) are more aggressive and adventurous

Question 20

What is a PET scan?

Answer 20

Used to scan and make detailed three-dimensional images of the inside of the body

Question 21

Damage to the pre-frontal vortex of the brain can cause what?

Answer 21

May cause individuals to have an altered behaviour pattern

Being more immature and having an increased loss of self-control as well as having an inability to modify behaviour

Question 22

What case study could be used to support the idea of brain abnormality?

Answer 22

Phineas Gage
Rod went through the left frontal lobe, associated with mental and emotional functions
His personality and behaviour was affected. He had bad language, anti-social, bad manners and became a liar

Question 23

How does serotonin affect behaviour?

Answer 23

Some studies show that serotonin are linked to higher aggression
Serotonin controls a person’s mood

Question 24

What did Scerbo and Raine’s meta-analysis show?

Answer 24

They conducted a meta-analysis on 29 studies into anti-social adults and children and found low levels of serotonin in all of them.

Question 25

How can serotonin levels be controlled?

Answer 25

Through diet

In foods such as: dark chocolate fish, cheese, nuts, salmon, turkey and chicken

Question 26

What is roid rage?

Answer 26

People who take large amounts of steroids and become extremely violent

Question 27

What are the strength of twin studies?

Answer 27

1. It is a natural experiment with the biological relationship between the twins being a natural occurring variable
2. Christiansen (1977) supports criminality having a genetic component
3. Results have helped in the prevention of vulnerable disorders

Question 28

What are the limitations of twin studies?

Answer 28

1. Lange (1929) were not controlled properly and lacked validity
   Wasn’t clear if twins were MZs or DZs because the decision was based on looks
2. Small sample of twins, so cannot be generalised
3. Of twins were brought up the same, criminality could be due to shared environment not genetics