Lesson 4 – Genetic and Neural Explanations

Question 1

What does the genetic explanation for crime suggest?

Answer 1

Genetic explanations for crime suggest that would-be offenders inherit a gene 🧬 or combination of 🧬 that predisposes them to commit crime

Question 2

Which psychologist conducted an experiment to investigate the genetic explanation of crime?

Answer 2

Lange (1930)

Question 3

What did Lange do to investigate the genetic explanation of crime and what did he find?

Answer 3

Lange (1930)- investigated 13 monozygotic (identical) 👯‍♀️ and 17 dizygotic (non-identical) 👯‍♀️
At least 1 of 👯‍♀️ in each pair served time in prison
10/13 pairs of monozygotic 👯‍♀️- both spent time in prison
2/17 pairs of dizygotic 👯‍♀️- both spent time in prison

Question 4

What does polygenic mean in the context of criminal behaviour?

Answer 4

Criminal 🏃‍♂️ could be polygenic- means ✖️ 1 single gene is for offending- instead many 🧬 responsible for causing criminal 🏃‍♂️ (known as candidate 🧬)

Question 5

Which study looked into the specific genes potentially responsible for criminal behaviour?

Answer 5

Tilhonen et al. (2014)- conducted genetic analysis of over 900 Finnish offenders- revealed abnormalities of 2 🧬 potentially associated with violent crime:
1) MAOA 🧬- controls dopamine and serotonin in 🧠- linked to aggressive 🏃‍♂️
2) CDH13 🧬 - linked to substance abuse and attention deficit disorder (✖️ maintain attention … ✖️ concentrate … ✖️ do well in school … ⬆️ likely to resort to crime
Within Finnish sample individuals with this ⬆️-risk combination of genes were 13 times ⬆️ likely to have history of violent 🏃‍♂️ compared to control group

Question 6

What is the diathesis stress model?

Answer 6

Holds that genetics influence criminal 🏃‍♂️ BUT ALSO moderated by effects of environment
… tendency towards criminal 🏃‍♂️ may come through combination of genetic predisposition and biological or psychological triggers e.g. being raised in a dysfunctional environment

Question 7

What is the neural explanation to criminal behaviour?

Answer 7

Evidence suggests there may be neural differences in 🧠 of criminals compared with non-criminals- diagnosed criminals with anti-social personality disorder (APD) (associated with ⬇️ emotional responses and lack of empathy … ✖️ feel guilty for actions- characterises many convicted criminals)

Question 8

What evidence is there to support the neural explanation for criminal behaviour?

Answer 8

Several dozen 🧠-imaging studies- demonstrate that individuals with anti-social personalities have ⬇️ activity in pre-frontal cortex of 🧠(regulates emotional 🏃‍♂️ )
Raine et al. (2000)- found an 11% reduction ⬇️ in volume of grey matter in prefrontal cortex of ppl with APD compared to control group

Question 9

What has recent study suggested about criminals with APD?

Answer 9

Recent research suggested that criminals with APD experience empathy BUT ⬆️ sporadically than rest of us
Keysers et al. (2011)- found that only when criminals asked to empathise (with person on film experiencing pain) did their empathy reaction (controlled by mirror neurons in 🧠) activate- suggests that APD individuals are ✖️ totally without empathy but may have neural switch that needs to be turned on in order to experience it- in normal 🧠 empathy switch permanently switched on

Question 10

What are the evaluation points for genetic and neural explanations?

Answer 10

👎- concordance rates in MZ twins are ✖️ ⬆️ and leave plenty of room for non-genetic environmental factors- ALSO concordance rates may be due to shared learning experiences rather than 🧬
👎- 🧠 scanning studies (such as Raine et al., 2000) show pathology in 🧠 of criminal psychopaths BUT ✖️ conclude whether these abnormalities genetic 🧬 or signs of early abuse
👎- genetic and neural explanation of criminal 🏃‍♂️ is example of biological reductionism- criminality complex and explanations that reduce offending 🏃‍♂️ to a 🧬 or imbalanced neurotransmitter inappropriate and overly simplistic
Criminal 🏃‍♂️ does seem to run in families BUT so does emotional instability, mental illness, social deprivation and poverty- ALSO twin studies never show 100% concordance rates in monozygotic (MZ) twins … 🧬 cannot be only explanation for criminal 🏃‍♂️
👎- genetic and neural explanation of criminal 🏃‍♂️ example of biological determinism- dilemma for legal system as if someone has a criminal 🧬 they ✖️ have personal and moral responsibility for crime … unethical to punish someone who ✖️ have free will