Criminal behaviour

Subdecks (2)

Cards (88)

  • Genetic factors
    More than one gene can predispose individuals to criminal behaviour
  • Twin studies
    • Identical twins (MZ) showed 62% similarity in delinquent behaviour compared to 21% in non-identical twins (DZ)
  • Candidate genes
    MAOA and CDH-13
  • Brunner et al (1993) found men in a Dutch family with histories of impulsivity and violence shared abnormally low MAOA
  • Tiihonen et al (2015) found evidence of low MAOA in 400 offenders, estimated 5-19% of crime in Finland due to genetics
  • Diathesis-stress model
    Genes no longer directly influence behaviour, instead genes interact with environment
  • Epigenetics - genes can be switched on/off by environmental factors
  • Caspi et al (2002) found 12% of men with low MAOA who experienced maltreatment were responsible for 44% of violent crime
  • Differences in the brain
    • Reduced functioning in the prefrontal cortex linked to impulsivity and lack of behavioural control
    • Low serotonin levels may lead to impulsive aggression
    • Dopamine hyperactivity may enhance this effect
    • Very low noradrenaline associated with aggression/violence
  • Inherited personality
    Eysenck's theory - some people inherit personality types that predispose them to criminal behaviour
  • Amygdala
    Structure and function of the amygdala
  • Amygdala
    • Made up of grey matter; a collection of neurons densely packed together into clusters of 13 nuclei
    • Located in the medial temporal lobe and part of the wider collection of brain structures (Limbic system)
    • Two amygdala, one per brain hemisphere
  • Further implicated by Marian
    1952
  • Amygdala
    • Neurally linked to: hypothalamus, hippocampus, prefrontal cortex
    • Has a wide spread influence on functions and ultimately on behaviour
    • Plays a major role in response to environmental threats
  • Amygdala
    Linked to aggression
  • Toccaro et al (2001) study on effects of amygdala on aggression
    1. Participants viewed images of faces
    2. Had fMRI scan
    3. Key difference: high amygdala activity when viewing angry faces, showing link between amygdala and aggression
    4. Angry faces are an end signal of threats
  • Amygdala dysfunction
    Affects aggression and antisocial/criminal behaviour
  • Drao and colleagues (2010) study on amygdala and fear conditioning
    1. Longitudinal study of 345 participants
    2. Tested for fear conditioning to an angry face
    3. Those who showed no fear conditioning at age 3 were more likely to be involved in criminal behaviour 20 years later
    4. Suggests a causal relationship between amygdala dysfunction and antisocial/criminal behaviour
  • Amygdala dysfunction can inhibit aggression through fear conditioning
  • Cognitive distortional thinking reality become twisted so they perceive it is no longer the reality
  • Results of cognitive disorders relevant to crime
    • Persons views of event are wrong but they think it's right
    • Negative interpretations lead to aggressive behaviour
    • Minimisation explains offenders may reduce any negative interpretations of their behaviour before/after crime
  • Hostile attribution bias
    When we observe someone's action, I draw inference to what is their intention is malicious
  • Negative interpretations lead to aggressive behaviour and if you have it, you are likely to have increased levels of aggression
  • Minimisation explains offenders may reduce any negative interpretations of their behaviour before/after crime
  • Individuals may accept the consequence of own behaviour & negative emotions can be reduced
  • Example of minimisation
    • Burglary planning, crime to steal few things from wealthy family, very minimise the effect because of this thinking they don't feel bad
  • Levels of moral reasoning
    Preconventional level: focus on rules enforced by punishment
    Conventional level: right defined by what's expected
    Postconventional level: individual right more important than law, universal ethical principles
  • Most adults are at conventional level, the belief that individual right more important than law, & offender might think it's acceptable to break laws to protect family
  • Most are at preconventional level, believe breaking law is justified if the reward outweighs cost/punishment avoided
  • Children were at stage 1 and 2 of moral reasoning
  • Eysenck's personality theory
  • EYSENCKS PERSON
    Theory of personality
  • Eysenck's theory of personality

    • Based on the idea that character traits tend to cluster along 3 dimensions
    • Extraversion-introversion, neuroticism-stability, psychoticism-normality
  • Extraversion
    Outgoing, positive emotions but bored easily
  • Neuroticism
    Emotional instability, experience negative emotions
  • Biological basis of personality traits
    • Each trait has a biological basis, mainly innate
    • 67% of the variance for the trait is due to genetic factors
  • Arousal
    • Determines the expression of personality traits
    • Under-aroused requires more stimulation, over-aroused avoids arousal
  • Extraversion
    Seek external stimulation to increase arousal
  • Neuroticism
    Determined by levels of stability in the sympathetic nervous system, responds to threat (fight/flight)
  • Stable person
    More unreactive nervous system, calm under pressure