Forensic psychology

What is Hans Brunner research

• Geneticist working with a family of criminals spanning 19700-1900s in a hospital in Netherlands s

• Males in the family had a criminal history dating back to 1870

  • Crimes like trying to rape his sister and attempted murder

• Bruner et al (1993) - highlighted the family suffer from a rare genetic condition carried by females but only affecting the males

  • Enzyme called MAOA

    • Normally regulates the breakdown of neurotransmitters

    • Those with MAOA-L (low activity version of the gene) - results in more neurotransmitters in the brain since there is less MAOA to break them down

      • Then leads to heightened agression, cognitive compromise and lower IQ - thus couldn’t restart their more agressive behaviours

What is Caspi et al

• Caspi et al, 2002) investigated whether a specific genetic vulnerability could explain why some children who experience abuse go on to commit antisocial and criminal behaviour as adults, while others do not. The Study: They tracked a large cohort of males, looking at variations in the MAOA gene (comparing low-activity vs. high-activity versions) alongside their exposure to childhood maltreatment.

• The Results: They found that childhood maltreatment significantly predicted later antisocial and violent behaviour only in males who carried the low-activity variant of the MAOA gene. Those with the high-activity gene who experienced abuse did not show the same high rates of criminality.

• Conclusion: This provided clear evidence for a gene-environment interaction (diathesis-stress model), proving that the gene alone does not cause crime, but rather moderates a person's vulnerability to environmental stressors like abuse.

What is Tilhonen et al

Tilhonen et al (2015) studied 900 criminals in Finland. 78 of them were extremely violent offenders. Between then they have committed 1154 murders,

• The Results: They found that individuals with specific risk variants in both the MAOA gene and the CDH13 gene (often referred to in exams by its gene family or abbreviation) were significantly more likely to have a history of extremely violent, repeated offenses.

• Conclusion: This provided large-scale empirical evidence that specific genetic profiles affecting brain chemistry and impulse control-are strongly correlated with a predisposition toward severe violent crime, though the researchers noted that environmental catalysts like substance abuse still play a crucial role.

• Is this research socially sensitive?

What do neural explanations for criminal behaviour include

• Brain structure

• Brain chemistry

How do neurotransmitters impact criminal behaviour

Serotonin: Linked to mood and impulsiveness

• Moir and Jessel (1995) - cite a number of human and animal studies which suggest a link between low levels of serotonin and agression - linked to criminal behaviour

• Scerbo and Raine (1993) - Conducted a meta-analysis on 29 pieces of research into anti-social adults and children, finding in all cases, low levels of serotonin

Dopamine: Linked to the dopaminergic pathway, which results in pleasure, which is a rewarding feeling and a desire to repeat certain behaviours. This is why dopamine had been linked to addiction and substance abuse, and therefore through this it has an indirect link to criminal behaviour

• Buitelaar (2003) - found that juvenile delinquents given dopamine antagonists which reduce levels of dopamines , shows a decrease in agressive behaviour

• Couppis (2008) - argues that some individuals who engage in certain criminal behaviours may experience an increase in dopamine and as a result seek out such experience again due to the reward feeling

What are mirror neurones

• Brain cels that fire both when a person performs an action and when they observe someone else performing that action. They are linked to empathy, social cognition and understanding other peoples intentions

  • Keysers et al 2011 - Found that individuals with APD don’t automatically activate their empathy

How does the prefrontal cortex impact criminal behaviour

• Responsible for executive function, which are high-level cognitive processes that control and supervise other brain systems

• These functions include impulse control, emotional regulation and having a working memory

• The PFC integrates information from various parts of the brain to enable goal directed thought and behaviour

How do the Pre frontal cortex (PFC) and Amygdala lead to criminal behaviour

Ulkire Marie Meinhof

• Had a conventional life and was a respected journalist

• Later she was a radicalised and joined an extreme leftist party

• Eventually co-founded the ‘Red Army Faction’

  • This was a west German militant group responsible for a number of bombings, kidnaps and murder

• In 1962 Meinhof had had a benign tumor surgically removed; the 1967 autopsy showed that ruminants of the surgical scar tissue impinged on her amygdala - could have been responsible for the radical change