L3 - Neurobiological Risk Factors for Antisocial and Violent Behaviour

Question 1

What are two types of genetic influence?

Answer 1

1. Behavioural genetics (identical twin studies, adoption studies, twins separated at birth)
2. Molecular genetics (candidate genes)

Question 2

What percentage of the population are twins?

Answer 2

2%

Question 3

What is another name for dizygotic twins?

Answer 3

Fraternal twins.

Question 4

What percentage of twins are fraternal/dizygotic?

Answer 4

92%

Question 5

In dizygotic twins, how many eggs are fertilised by how many sperm cells?

Answer 5

2 eggs are fertilised by 2 separate sperm cells

Question 6

In monozygotic twins, how many eggs are fertilised by how many sperm cells?

Answer 6

1 egg is fertilised by 1 sperm. The fertilised egg later splits into two identical eggs.

Question 7

In twin studies, the contribution of 3 factors to antisocial behaviour is worked out. Which 3 factors are they?

Answer 7

• Genetics (heritability) h^2
• Shared environment c^2
• Non shared environment e^2

Question 8

Heritability for ASB ranges between what across all different studies?

Answer 8

Between around 0.4-0.5.

Question 9

What are the heritabilities for aggressive and non aggressive ASB?

Answer 9

0. 65 for aggressive

0. 48 for non-aggressive

Question 10

What are the heritabilities for reactive and proactive aggression?

Answer 10

Reactive - 0.39

Proactive - 0.50

Question 11

Heritability for early-onset ASB is ______ , especially when it occurs across many settings, is persistent and severe and involves psychopathic tendencies. These children have a heritability of _______.

Answer 11

Strongest, 0.75

Question 12

What is the typical design of most adoption studies?

Answer 12

Experimental group involves foster children who’s biological parents are criminals.
Control group are foster children who’s biological parents are not criminals.

Question 13

What results would have to be shown to conclude a significant genetic influence of ASB in twin studies and why?

Answer 13

If the experimental group shows higher levels of ASB than the control group.
Because the experimental group’s biological parents are criminals.

Question 14

What did Mednick et al., (1984) find about the heritability of property crimes?

Answer 14

Significant positive correlation between adoptees and their biological parents for convictions of property crimes.
No such correlation found for violent crimes.

Question 15

Adoption studies have robust findings despite differences in what?

Answer 15

• age of participants
• study periods
• country
• measures of ASB
• study design

Question 16

Caspi et al., (2002) found gene-environment interactions between the low activity MAOA allele and childhood maltreatment for which aspects?

Answer 16

• conduct disorder
• conviction for violent offences
• disposition towards violence
• antisocial personality disorder symptoms

Question 17

The low allele of the MAOA gene has been shown to be linked to what?

Answer 17

• higher levels of aggression following provocation (McDermott et al., 2009)
• greater brain response following social exclusion (Eisenberger et al., 2007)

Question 18

Raine studied which biosocial effects on violent crime?

Answer 18

Birth complications and maternal rejection.

Question 19

What did Raine find when studying the biosocial influences on violent crime?

Answer 19

Significant interaction between biological (birth complications) factors and social factors (maternal rejection) increased the rate of violent crime convictions.

Question 20

Why might birth complications lead to increased violent behaviour?

Answer 20

Those exposed to hypoxia have decreased neural densitiy, believed to lead to learning, decision making and emotion regulation deficits.

Question 21

Why might maternal rejection lead to increased violent behaviour?

Answer 21

Lack of love, care and a nurturing environment may bring out cold, aggressive traits.

Question 22

Which factors were accounted for in studies which still found a link between smoking during pregnancy and antisocial behaviour?

Answer 22

• Low socio-economic status
• parental crime and ASB
• low maternal education level
• bad parenting
• mother’s age at child’s birth
• family size
• bad parenting
• family problems
• parental psychiatric diagnoses
• genetic influences

Question 23

What might be the mechanisms behind smoking during pregnancy and increases in antisocial behaviour?

Answer 23

Babies, infants or adolescents exposed to nicotine found to have deficits in gray matter volume in key cortical and subcortical areas involved in emotion regulation.

When nicotine passes through the placenta, a reduction of uterus blood flow eventuates. This leads to a decrease in the nutrients and oxygen delivered to the foetus, (hypoxia), which can cause death of neurons.

Question 24

Which indirect measure of brain development was used by Jaddoe et al., (2007) to suggest effect of nicotine exposure on brain development?

Answer 24

Head circumference. Reduced circumference in babies exposed to nicotine prenatally.

Question 25

Adolescents exposed prenatally to nicotine show what? (+studies)

Answer 25

- lower amygdala volume (Haghighi et al., 2013) - lower cortical thickness of the orbitofrontal cortex (Toro et al., 2008) - Increased drug experimentation (Loftipour et al., 2009)

Question 26

Deficits in brain regions as a result of nicotine exposure leads to what impairments?

Answer 26

Neuropsychological impairments in: - executive functioning - memory - attention

Question 27

What does FAS stand for?

Answer 27

Foetal Alcohol Sydrome

Question 28

What are some physical characteristics of FAS?

Answer 28

- small head - folds of skin between eyes and nose - smooth area between nose and upper lip - thin upper lip - small eye openings - short nose - flat upper part of the nose - underdeveloped jaw

Question 29

What are some symptoms of FAS?

Answer 29

- Craniofacial abnormalities - Growth retardation - CNS dysfunction, leading to learning disabilities and low IQ.

Question 30

What did Popova's (2016) meta-analysis show about the main disorders caused by FAS?

Answer 30

ASB and conduct disorder is the most common in individuals with foetal alcohol syndrome.

Question 31

Define maltreatment according to the World Health Organisation.

Answer 31

All forms of physical and/or emotional ill-treatment, sexual abuse, neglect or negligent treatment or commercial or other exploitation, resulting in actual or potential harm to the child’s health, survival, development or dignity in the context of a relationship of responsibility, trust or power.

Question 32

Name 4 types of maltreatment.

Answer 32

Physical abuse Emotional abuse Sexual abuse Neglect

Question 33

What is neglect?

Answer 33

A persistent failure to meet a child’s basic physical and/or developmental needs.

Question 34

All types of maltreatment are linked with what?

Answer 34

- Poorer mental health | - Elevated levels of delinquency

Question 35

The majority of maltreated children experienced how many types of abuse?

Answer 35

More than one

Question 36

How do maltreated children react when they see angry faces, compared to children who have not been maltreated?

Answer 36

The amygdalae of maltreated children are hyperactive - far more active than those of 'normal' children.

Question 37

According to De Brito et al., (2013), what were maltreated children more likely to have?

Answer 37

Conduct disorder and (amygdala?) hyperactivity.

Question 38

Why might maltreated children be more likely to turn to violence?

Answer 38

Increased activity in amygdala when shown angry faces --> when experiencing disagreements in life, they may be more emotionally unstable and therefore react much more than they should.

Question 39

De Brito et al., (2013) says that child maltreatment leads to decreased gray matter volume in which regions?

Answer 39

Medial orbitofrontal cortex | Left middle temporal gyrus

Question 40

Kelly et al., (2015) linked decreases in gray matter volume in maltreated children to what?

Answer 40

Peer problems. Maltreated children have decreased gray matter in areas needed for emotion and decision making, which impairs their ability to interact effectively with peers.

Question 41

How do maltreated children react when they see happy faces, compared to children who have not been maltreated?

Answer 41

Hyperactivity in amygdalae. Seems that the amygdalae of maltreated children activate immediately in response to any information about imminent danger.

Question 42

How do reactions of amygdala activity in maltreated children tell us about the nature of their maltreatment?

Answer 42

The more sensitive the amygdala is in response to happy/angry faces, the longer the duration of abuse

Question 43

What is the left middle temporal gyrus important for, and what does this mean for maltreated children with reduced gray matter volume in this area?

Answer 43

Autobiographical memory. Possible that the maltreatment has decreased the encoding of autobiographical memories - easier for children to forget/harder for them to clearly remember what has happened to them.

Question 44

Did maltreated children show overt symptoms whilst at mainstream schools? What does this show about the effects of maltreatment on overt symptoms

Answer 44

No. Maltreatment may be a pre-disposition to overt psychological symptoms later in life.

Question 45

Which disorders does maltreatment increase the risk of later in life?

Answer 45

Depression and substance abuse among others.

Question 46

What did Glenn and Raine (2014) show about the (almost causal) link between ventral prefrontal cortex dysfunction and paedophilia?

Answer 46

When the vPFC was displaced by a tumour in 40 year old schoolteacher Michael, his overt paedophilic behaviour emerged. Whenever the tumour was cut out (resected) his behaviour returned to normal.

Question 47

What does ASPD stand for?

Answer 47

Antisocial personality disorder

Question 48

What is ASPD?

Answer 48

A personality disorder that indexes a life-long pattern of antisocial behaviour

Question 49

What are the symptoms of ASPD?

Answer 49

- impulsivity - repeated criminality - consistent irresponsibility - repeated fights/assaults - recklessness - deceitfulness - lack of remorse

Question 50

According to Andersen et al., (1999) and Meyers et al., (1992), lesions in vmPFC leads to changes in what in individuals with acquired antisocial personality disorder?

Answer 50

- Behaviour - Affect - Personality

Question 51

What is the vmPFC?

Answer 51

Ventromedial Prefrontal Cortex

Question 52

What is the vmPFC important for?

Answer 52

Processing of risk and fear

Question 53

Children with conduct problems show reductions in which brain regions?

Answer 53

Medial PFC

Question 54

Decreased gray matter in the orbitofrontal cortex is associated with what?

Answer 54

Substance use disorders

Question 55

What are the two theories linking low resting heart rate with ASB?

Answer 55

Fearlessness Theory (Raine, 1993) Sensation-Seeking Theory (Quay, 1965; Eysenk, 1997)

Question 56

How does the Fearlessness Theory explain the link between low resting heart rate and antisocial behaviour?

Answer 56

Low resting heart rate is associated with low fear, meaning early fear conditioning may not have developed normally. This would mean consequences of ASB are not feared/aversive, increasing the likelihood of engagement in AS behaviour.

Question 57

How does the Sensation-Seeking Theory explain the link between low resting heart rate and antisocial behaviour?

Answer 57

Low resting heart rates are linked with with low autonomic arousals, which is an unpleasant physiological state. Therefore, activities which increase heart rate and arousal are engaged in to avoid/reduce the uncomfortable state

Question 58

What did Birbaumer et al., (2005) find about deficient fear conditioning in psychopathy

Answer 58

Healthy controls showed enhanced activation in the limbic-prefrontal circuit (amygdala, orbitofrontal cortex, insula, and anterior cingulate) during the acquisition of fear. (lower activation of these areas in psychopathic individuals