Forensics- Biological Explanations: Genetics And Neural Explanations Flashcards
Genetics -
Genes consist of DNA strands. DNA produces ‘instructions’ for general physical features of an organism (such as eye colour, height) and also specific physical features (such as neurotransmitter levels and size of brain structures). These may impact on psychological features (such as intelligence and mental disorder). Genes are transmitted from parents to offspring, i.e. inherited.
Neural explanation -
Any explanation of behaviour (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.
What do genetic explanations for crime suggest?
Genetic explanations propose that individuals inherit genes or combinations of genes that predispose them to commit crimes.
What evidence supports genetic explanations for crime?
Evidence comes from twin studies, adoption studies, and research on candidate genes, such as the MAOA and CDH13 genes linked to aggressive behavior and violent crime.
What did Johannes Lange’s twin study (1930) find?
Lange found that 10 out of 13 identical (MZ) twins had a co-twin who was also in prison, compared to only 2 out of 17 non-identical (DZ) twins, suggesting genetic factors play a significant role in offending behavior.
What did Crowe’s adoption study (1972) reveal?
Crowe found that adopted children with a biological parent who had a criminal record had a 50% risk of having a criminal record by age 18, compared to a 5% risk for those without a criminal biological parent.
What candidate genes are associated with violent crime?
The MAOA gene (linked to aggression) and the CDH13 gene (linked to substance abuse and ADHD) have been associated with violent crime. Individuals with both genes were 13 times more likely to have a history of violent behavior.
What is the diathesis-stress model in relation to crime?
The diathesis-stress model suggests that a genetic predisposition for criminal behavior may be triggered by environmental factors, such as a dysfunctional upbringing or criminal role models.
What neural differences are found in criminals?
Criminals, particularly those with antisocial personality disorder (APD), show reduced activity in the prefrontal cortex, which regulates emotional behavior, and an 11% reduction in grey matter volume in this area.
What are the problems with twin studies in genetic research?
Twin studies often have small sample sizes, rely on appearance rather than DNA to determine zygosity, and may be confounded by shared environments, making it difficult to isolate genetic influences.
What role do mirror neurons play in criminal behavior?
Mirror neurons control empathy. Research by Keysers et al. (2011) found that criminals with APD could experience empathy sporadically, suggesting their empathy ‘switch’ can be turned on and off, unlike in non-criminals.
What did Mednick et al.’s adoption study (1984) find?
The study found that adoptees with criminal biological parents had a higher likelihood of criminal convictions (20%) compared to those without (13.5%). This supports the role of both genetics and environment in offending behavior.
What are the limitations of adoption studies?
Adoption studies are complicated by late adoptions, ongoing contact with biological parents, and the fact that findings often apply only to petty crimes, not violent offenses.
What is biological reductionism in the context of criminality?
Biological reductionism refers to oversimplifying criminal behavior by attributing it solely to genetic or neural factors, ignoring other influences like social deprivation, poverty, and mental health.
What does the relatively low concordance rate in twin studies suggest?
Low concordance rates suggest that while genetics play a role, environmental and social factors also significantly influence criminal behavior.
What is biological determinism, and why is it problematic in criminology?
Biological determinism suggests that criminal behavior is predetermined by genes, raising ethical dilemmas about personal responsibility and sentencing, as it conflicts with the legal system’s emphasis on free will.
What ethical dilemmas arise from the idea of a ‘criminal gene’?
The discovery of a ‘criminal gene’ challenges the legal system’s basis of personal responsibility and raises questions about how society should treat individuals suspected of carrying such genes.
What is the role of the prefrontal cortex in criminal behavior?
The prefrontal cortex regulates emotional behavior. Reduced activity and grey matter volume in this area are associated with antisocial personality disorder and criminal behavior.
How does the diathesis-stress model apply to crime?
It suggests that genetic predispositions for criminal behavior may only manifest when triggered by environmental stressors, such as a dysfunctional upbringing or exposure to criminal influences.
What is the significance of the MAOA and CDH13 genes in criminal behavior?
These genes are linked to aggression, substance abuse, and ADHD, and individuals with both genes are significantly more likely to exhibit violent behavior.
What are the implications of neural explanations for criminal behavior?
Neural explanations highlight brain differences in criminals, such as reduced prefrontal cortex activity and sporadic empathy, suggesting biological factors contribute to criminal behavior.
What is the importance of considering environmental factors in criminal behavior?
Environmental factors, such as upbringing and social conditions, interact with genetic predispositions, making it essential to consider both when explaining criminal behavior.
