Biological theories of criminality: genetic theories

Question 1

What is the genetic explanation?

Answer 1

Criminality is the result of genes inherited from biological parents

Question 2

What is monozygotic?

Answer 2

Identical twins that share 100% of the same genes

Question 3

What is dizygotic?

Answer 3

Non-identical twins that share only 50% of the same genes (like ordinary siblings)

Question 4

What is the environmental explanation?

Answer 4

Criminality is the result of the surroundings a child grows up in

Question 5

What is a chromosome?

Answer 5

Made from DNA and protein. Carry genetic information we inherit from our parents. Most people have 23 pairs

Question 6

What is a super male?

Answer 6

Another term for XYY syndrome. Those affected carry an extra Y (male) chromosome on one of their 23 pairs

Question 7

What were the key ideas of the twin in twin and adoption studies?

Answer 7

If crime is genetic – identical (Mz) twins should have identical criminality

Question 8

What were the findings of the twin in twin and adoption studies?

Answer 8

Christiansen: Concordance in criminality Mz = 52% vs Dz = 22%

Question 9

What were the key ideas of the adoption in twin and adoption studies?

Answer 9

Adoptees share environment of adoptive parents/genes of biological parents. If genetic, criminality will match biological parents more

Question 10

What were the findings of the adoption in twin and adoption studies?

Answer 10

Mednick et al: birth parent concordance = 20% vs. adopted parent concordance = 14.7%

Question 11

What is one strength of the twin and adoption studies?

Answer 11

Twin & adoption studies give some support to genetic explanations

Question 12

What is a second strength of the twin and adoption studies?

Answer 12

Adoption studies overcome the problem of isolating genes and environment

Question 13

What is a third strength of the twin and adoption studies?

Answer 13

Research design of Adoption studies is logical (nature vs nurture)

Question 14

What is one limitation of the twin and adoption studies?

Answer 14

If criminality was only genetic MZ twins would have 100% concordance

Question 15

What is a second limitation of the twin and adoption studies?

Answer 15

It is impossible to isolate genetic effects fully from environmental ones

Question 16

What is a third limitation of the twin and adoption studies?

Answer 16

Adopted children are often placed with similar families to their birth family

Question 17

What were the key ideas of Jacob’s XYY study?

Answer 17

XYY syndrome in males makes them genetically predisposed to criminality

Question 18

What was the study of Jacob’s XYY study?

Answer 18

Compared rate of XXY in imprisoned criminals with general population

Question 19

What were the findings of Jacob’s XYY study?

Answer 19

Higher than average proportion of inmates had XYY

Question 20

What were the features of XYY?

Answer 20

Very tall, well-built, low intelligence, high aggression, violent

Question 21

What is one strength of Jacob’s XYY study?

Answer 21

acob et al found association with XXY and violent prisoners

Question 22

What is a second strength of Jacob’s XYY study?

Answer 22

Price & Watmore found links with XYY and property crime

Question 23

What is one limitation of Jacob’s XYY study?

Answer 23

Having the syndrome doesn’t mean that is the cause of crime

Question 24

What is a second limitation of Jacob’s XYY study?

Answer 24

XXY men fit stereotype of violent offenders – labelling theory

Question 25

What is a third limitation of Jacob’s XYY study?

Answer 25

Low intelligence of XYY may give higher chance of being caught

Question 26

What is a fourth limitation of Jacob’s XYY study?

Answer 26

Syndrome is too rare to explain much crime