biological explanation: genetic and neural

Question 1

twin studies

Answer 1

the concordance rate of twins for criminal behaviour gives us an indication of the extent that offending behaviour could be inherited

Question 2

twin studies: Christiansen 1977

Answer 2

MZ : 35%
DZ: 13%
sample size: 3586 twins in Denmark

Question 3

A03: TS-concordance rate isn’t 100%

Answer 3

so interaction between environment + genetics together produces outcome of criminality- suggested also by medick et al (1984) adoption study

Question 4

Twin studies: Raine 1993

Answer 4

MZ:52%
DZ:21%
Sample size:review of 13 studies

Question 5

candidate genes- Tiihonen et al 2014

Answer 5

-MAOA gene ‘warrior gene’
-CDH13 (code for neurotransmitters such as D+S) ‘associated w/ ADHD + substance abuse’
-800 Finnish offenders tested for gene
-5-10% of all violent crimes in Finland attribute w/these genotypes

Question 6

Diathesis stress model

Answer 6

-cup analogy
-if genetics play a part its also likely their affected by environment
-crime behaviour come about through combination of genetic predisposition + biological/psychological trigger

Question 7

DTSM: support-mednicks et al (1984)

Answer 7

-analysed 14,427 adoptees + records of adoptive n biological parents
-“siblings adopted separately into different homes tended to be concordant for convictions, especially if the shared biological father also had a record of criminal behaviour”
- however, cannot rule out SLT as highest conviction rate was when both bio n adopt parents had been convicted = 24%

Question 8

serotonin

Answer 8

neurotransmitter linked to mood + impulsiveness
low serotonin = no self control

Question 9

serotonin study- Moir + Jessel 1995

Answer 9

used animal+human studies that suggest link between low levels of serotonin + aggression
-link to criminal behaviour

Question 10

serotonin study: scerbo + raine 1993

Answer 10

-meta analysis on 29 pieces of research on antisocial ppl
-low level of serotonin in all cases

Question 11

dopamine

Answer 11

link to pleasure
-desire to repeat certain behaviours
-link to addiction+ substance abuse
-indirect link to crime

Question 12

dopamine study: buitelar 2003

Answer 12

-juvenile delinquents given dopamine antagonists which reduce levels of dopamine
-show decrease in aggression

Question 13

dopamine study: couppis 2008

Answer 13

-some criminals may experience increase in dopamine + as result seek out experiences again due to reward feeling

Question 14

frontal lobes

Answer 14

-part of the neocortex has been linked to higher function such as social behaviours + planning

Question 15

fl: bower + ptice 2001

Answer 15

found link between FL dysfunction + violent crime

Question 16

fl: kendel + freed 1989

Answer 16

FL damage + antisocial behaviour are linked

Question 17

KEY: Antisocial personality disorder- raine et al 2000- procedure

Answer 17

-aim:identify regions specific to offenders charged w/ murder or manslaughter, who had pleaded not guilty by reason of insanity
-method: 41 murders + 41 non murderers, PET scanning, matched pairs, Their brains were scanned 10 times at 10 minute intervals to pick up differences in glucose metabolism in the cerebral cortex and sub-cortical layers

Question 18

Raine et al 2000 findings

Answer 18

-results: reduced activity in prefrontal cortex (logical thinking + decision making)+corpuscallosm. abnormalities in activity of limbic system-amygdala

Question 19

amygdala

Answer 19

-part of limbic system
-linked w aggression+ emotion regulation

Question 20

AO3: limitation of Raine study

Answer 20

-faulty functioning could be due to trauma. not everyone w injury could be criminal
-cause+effect is unclear, doesn’t affect people w brain physiology in same way
-brain functioning issues might be due to a physical abuse in childhood
-small sample size-genersalised low

Question 21

AO3:neurotransmitters

Answer 21

-biochemical explanations are relevant to everyday life
-caused by mental illness
-research on neurotransmitters is conducted on animals+might not be valid for people
-redutionists + don’t take in condition of other factors + complexity of influence on human behaviour

Question 22

AO3: biological reductionism: katz et al (2007)

Answer 22

-though criminality runs in families so do other risk factors associated w/criminality (eg deprivation)
-stereotyping these children may lead to self fulfilling prophecies

Question 23

support 4 raine- Keysers et al 2011

humanity switch

Answer 23

-criminals have neural switch use to turn capacities for empathy on or off.
-lack empathy for victims