1. http://www. independent. co
The Mobley Defence
Real world application/issues and debates
Stephen Mobley ( ) was a convicted murderer executed by the State of Georgia for the 1991 killing of John C. Collins, a 25- year-old college student working nights as a Domino's pizza store manager. On appeal, Mobley's attorneys advanced a novel argument that Mobley was genetically predisposed to seeking violent solutions to conflict. The case was described as "perhaps the most widely cited case in which defence lawyers used genetic factors in the defence of their client".
Should genes ever be considered a legitimate legal defence? Why/not?

2. Genetic and Neural Explanations of offender behaviour
Aim: to examine and evaluate the genetic and neural explanations for crime.

3. Genetics and neural explanations
Genetics: Genes consist of DNA strands. DNA produces ‘instructions’ for general physical features of an organism (e.g. eye colour, height) and also specific physical features (such as neurotransmitter levels and size of brain structures). These may impact psychological features (such as intelligence and mental disorder). Genes are transmitted from parents to offspring , i.e. inherited.
Neural explanations: Any explanation of behavior (and its disorders) in terms of (dys)functions of the brain and nervous system. This includes the activity of brain structures such as the hypothalamus, and neurotransmitters such as serotonin and dopamine

4. Draw & label a rough outline of the brain Identify where the frontal lobe is

5. APD
Evidence suggests there may be neural differences in the brains of criminals and non-criminals.
Much of the evidence in this area has investigated individuals diagnosed with Antisocial Personality Disorder (APD) – formally known as psychopathy.
APD is associated with reduced emotional responses, a lack of empathy for feelings of others, and is a condition that characteristics many convicted criminals.

6. Neural explanations Gage, 1894.
Prefrontal cortex: individuals who experience antisocial personality disorder show reduced activity in the PFC, the part of the brain that regulates emotional behaviour.
Raine (2000) found an 11% reduction in the volume of grey matter in the PFC of people with APD compared to control groups.
Gage, 1894.
Railway worker – catastrophic damage to prefrontal lobes caused by a metal bolt catapulting through cheek and up through eye into brain (prefrontal area).
Recovered physically but went from being a sober, quiet family man to a violent drunk.
Prefrontal lobes keep behaviour in check, moderate impulses.

7. Neural explanations
Mirror neurons: are a type of brain cell that fires when you do an action, and also when you simply watch someone else doing the same action. They help us understand and interpret the actions of others. Keysers (2011) only when criminals were asked to empathise with others did their empathy reactions activate. This is controlled by mirror neurons. This suggests that criminals do experience empathy, although it is not an automatic response. These neurons fire in response to the actions of others.
Suggests that APD individuals are not totally without empathy but may have a ‘switch’ which can turn on or off, unlike a ‘normal’ brain whose mirror neurons are constantly ‘turned on’.
You're walking through a park when out of nowhere, the man in front of you gets smacked by Frisbee. Automatically, you recoil in sympathy.
Or you're watching a race, and you feel your own heart racing with excitement as the runners vie to cross the finish line first.

8. Neurotransmitters: task
What are the two main neurotransmitters associated with offending behaviours?
What behaviours are the neurotransmitters involved in?
Is there research to support the role of neurotransmitters in criminal behaviour?

9. Task
Outline the neural explanation to offender behaviour Swap explanations: more detail needed?

10. Genetic explanation

11. Outline what each of the below have to do with offender behaviour?
Twin studies
Adoption studies
Candidate genes
Diathesis-stress model

12. How can we test if genes play a part in criminal behaviour
How can we test if genes play a part in criminal behaviour? Who can we study?
Twin studies:
monozygotic twins (MZ-100%)
dizygotic twins (DZ- 50%)
Adoption studies:
Find out the effects of genes and the environment
Family studies:
Study rates of schizophrenia in different relatives. E.g. compare concordance rates between mother and child.
What is a concordance rate?
This is the coefficient value that is worked out by correlating the crime rate between 2 groups of people e.g. concordance between parent and child
The correlation coefficient tell us the likelihood of both parent and child engaging in criminal behaviours
The higher this number is the more chance there is of criminal behaviours developing
This can then be represented as a percentage value.

13. Twin studies recap 2 advantages of studying twins as a psychologist
2 disadvantages of studying twins as a psychologist

14. Research: twin studies
Christiansen (1977) examined over 3,500 twin pairs in Denmark and identified concordance rates of criminal behaviour as follows:
What do these findings suggest?

15. Genetic explanations – twin studies
Lange (1930); 13 MZ twins and 17 DZ twins where one of the twins in each pair has spent time in prison. 10 of the MZ twins and but only 2 of the DZ twins had a co-twin that had also spent time in prison. .

16. Adoption and family studies?
Task:
Fill out the table for twin and adoption studies

17. Candidate genes
Tiihonen et al (2014) revealed two abnormalities that may be associated with violent crime – the MAOA gene (controls dopamine and serotonin) and CDH13 (linked to substance abuse and attention deficit disorder). Tiihonen’s sample was 900 Finnish offenders. Individuals with this combination were 13 times more likely to have a history of violent behaviour. This research is in its infancy and has yet to be replicated. MAOA gene: controls dopamine and serotonin in the brain and has been linked to aggressive behaviour

18. Diathesis-stress model
Describe what the D-S model is based on this diagram:

20. Genetic explanations – Adoption Studies
Mednick et al (1984)
14427 Danish adoptees
13.5% were criminal with NO CRIMINAL PARENTS
14.7% were criminal with at least 1 Criminal ADOPTIVE PARENT
20% were criminal with at least 1 Criminal BIOLOGICAL PARENT
24.5% were criminal with at least 1 Criminal Adoptive Parent AND 1 Criminal Biological Parent

21. Evaluation?

22. Independent task
Each pick a point on your table to write a PEEL paragraph for (7 minutes)
Problems with twin studies
Biological reductionism
Issues with research investigating the brain
Biological determinism

23. Ex: can you think of 2 strengths/real world applications of the biological explanations?
Biological determinism presents problems for our legal system since it negates free will and raises the ethical question surrounding what society does with people who carry criminal genes
Many adoptees are adopted late so spend their infancy with their biological parents anyway. Some also maintain regular contact with their biological parents. This means that the parents may have had an environmental rather than biological impact.
Early twin studies are often unreliable since zygosity (whether twins are MZ or DZ) was based on appearance rather than DNA testing. Therefore they may lack validity.
Twin studied involve small sample sizes and the fact that most twins are raised in the same environment is a confounding variable as concordance rates may be due to shared experiences rather than genetics
Biological reductionism is an issue within these studies as criminality is complex and environmental factors must be considered.

24. Jim Fallon – warrior gene video
?language=en Discuss biological explanations to offender behaviour (16 marks)

25. Forensic continued

26. Attachment and psychopathology (20 minutes)

27. Evaluation (15 minutes)
Share your paragraphs

28. Essay: 20 minutes to write

29. Eysenck’s theory