Biological Theories

Question 1

What is the key idea of biological theories?

Answer 1

Crime is caused by faults in an individuals biological makeup. People may be predisposed to be criminals by their genes. Alternatively, people who look a certain way may be more likely to be criminal.

Question 2

What are the two physiological theories?

Answer 2

Cesare Lombroso (1876)-atavistic features

Sheldon (1949)-soma-types

Question 3

What are some of the atavistic features?

Answer 3

Low sloping forehead
Large protruding ears
Upturned nose
High cheekbones

Question 4

What are the three soma-types?

Answer 4

Ectomorph- thin and fragile
Endomorph- fat and soft
Mesomorph- muscular and hard

Question 5

Which soma-type is most likely and least likely to be criminal?

Answer 5

Most likely- mesomorph

Least likely- ectomorph

Question 6

Many people accuse lombroso of scientific racism because…

Answer 6

People suggest that his ideas were influential and supported the notions of pure blood and aristocracy, and that people with “defects” were more likely to be criminal.

Question 7

What is another weakness of lombroso’s theory?

Answer 7

His research was poorly controlled and he did not compare his sample of criminals to a non-criminal CONTROL GROUP. this means that his research could lack VALIDITY.

Question 8

Strengths of lombroso’s theory?

Answer 8

He was the first person to give criminology a scientific credibility.

His work heralded the beginnings of offender profiling.

Lombroso did acknowledge the idea that criminals can choose to be evil.

Question 9

What was Sheldon’s study that supported his theory?

Answer 9

He used a photographic study of collage students (some of whom were delinquents) and found that after rating the students on the LIKERT SCALE which rates their level of resemblance to the MESOMORPH body type, he found that the criminals had a HIGHER rating in the scale than the normal students.

Question 10

Strengths of Sheldon’s theory of soma types?

Answer 10

He used a large sample of 200 people for more accurate results.

He used a control group of non-offenders to compare his results to.

Question 11

Weaknesses of Sheldon’s theory?

Answer 11

He can’t explain how other body types can also be criminals (ectomorph and endomorph).

He ignores the role of learning in crime.

His theory may cause bias towards people with the mesomorph body type within the judicial system.

Question 12

What is the main idea of genetic theories?

Answer 12

Genetic theories suggest that criminality could be INHERITED.

This leads to the phrase being “born bad”

Question 13

What are the different genetic theories?

Answer 13

Twin studies.

Adoption studies.

MAOA gene.

XYY theory.

Question 14

How do we investigate twins in relation to genes and crime?

Answer 14

We study both MZ twins and DZ twins and we compare them in order to see if there are behavioural similarities between twins who share 100% of the same gene in comparison to only sharing 50%.

Question 15

What are the two types of twins?

Answer 15

MZ twins- monozygotic IDENTICAL twins.

DZ twins- dizygotic NON-IDENTICAL twins.

Question 16

What is the concordance rate?

Answer 16

The probability of 1 twin being a criminal if the other one is is called the CONCORDANCE RATE.

If both identical twins are criminals it suggests a very strong genetic link to criminality.

Question 17

Why is the concordance rate never 100%?

Answer 17

If crime was completely genetic, then if one twin had the criminal gene so would the other and the CR would be 100%
However… the CR is not 100%

This means that if one MZ twin is a criminal and the other isn’t, that twin must of had a “trigger event” e.g. abuse or trauma. The reason the CR can never be 100% is because of the twins different experiences and environment.

Question 18

What are the real concordance rates for MZ and DZ twins?

What is the supporting study linked to these statistics?

Answer 18

MZ twins- 35%

DZ twins- 13%

Study- Christiansen (1977) studied 3586 danish twins and found these concordance rates after studying each twin pair (MZ and DZ twins).

Question 19

Main weakness of twin studies?

Answer 19

We can never fully separate out the role of the environment. Most pairs of twins do not only share the same genes, but also the same upbringing which influences their behaviour.

Question 20

What is the purpose of adoption studies?

Answer 20

In adoption studies, researchers compare the similarity of behaviour between adoptees and biological offspring in order to see if you can separate nature from nurture.

If the child is more similar to their adoptive parent then it suggests that environment is more important. Alternatively, if they are more similar to their biological parent it suggests that genes are more important.

Question 21

What is the supporting study for adoption studies?

Answer 21

Crowe (1972) found that if an adoptees biological mother had had a conviction, they had a 50% chance of having a conviction. However, if the adoptees biological mother did not have a conviction, they had only a 5% chance of having received a conviction.

Question 22

Strength of adoption studies?

Answer 22

They help us to separate genes and environment because studies show that even if the adoptees has never met or been brought up by their biological parents, they still have a higher chance of being convicted if they were also.

Question 23

Weakness of adoption studies?

Answer 23

If the child is adopted later in life this could mean that the initial upbringing from their biological parents could have influenced their behaviour before being adopted.

This is why most of not all adoption studies are conducted with children who have been adopted at an early age.

Question 24

What is the MAOA gene important for?

Answer 24

The MAOA gene (aka the “WARRIOR GENE”), is important for controlling the amount of serotonin and dopamine in the brain.

Question 25

What is the XYY theory?

Answer 25

The XYY theory is the belief that criminals have an extra Y chromosome, giving them an XYY chromosome makeup instead of XY. Having this chromosome is associated with a strong compulsion to commit crime.
The extra chromosome caused makes to be unusually tall, aggressive and violent.

Question 26

What is the XYY theory linked to?

Answer 26

The XYY theory is also linked to people with learning disabilities.

This is a weakness for the XYY theory as people with learning disabilities are more vulnerable and susceptible to persuasion which makes it difficult for people to determine wether the extra chromosome is the cause for their behaviour.

Question 27

How did the media influence in the XYY theory?

Answer 27

In tv programs, the media referenced the XYY theory- MEDIA AMPLIFICATION- they sensationalised XYY.

Richard speck (study) was said by the media that his violent crimes were directly caused by his XYY gene however; it later came out that he never had the the extra Y chromosome.

Question 28

Weakness of the XYY theory?

Answer 28

It doesn’t take into account the environment. It focuses too strongly on genetics and ignores the behaviourist approach.