Neural and hormonal- aggression

Question 1

Neural mechanisms

Answer 1

• related to the nuerone
• large neural structures
• the actions of neural transmitters

Question 2

hormonal mechanisms

Answer 2

• hormonal messengers that influence the body

Question 3

what is the limbic system

Answer 3

• a set of neural structures located in the centre of the brain
• the amygdala and hypothalamus are linked to aggressive responses through fMRI
• processes emotional responses
• areas communicate with the orbitofrontal cortex (OFC)
• controls decision making which attempts to control aggression produced by the system

Question 4

what is serotonin?

Answer 4

• inhibitory neurotransmitter than is important in controlling/calming aggressive impulses
• serotonin in the orbitofrontalcortex controls aggressive impulses from the limbic system
• those with short variants of MAOA struggle to break down serotonin, so have higher levels, but are more aggressive

Question 5

what is testosterone?

Answer 5

• a male sex hormone, found in high levels in males (8x+ than Females)
• responsible for increased aggression
• high testosterone in the orbitofrontal cortex reduces activity= less able to regulate impulses from limbic system
• increases activity of amygdala resulting in more aggressive impulses

Question 6

role of hypothalamus in limbic system?

Answer 6

• integrating and expressing emotional response
• trigger aggressive behaviour through fight or flight

Question 7

role of the amygdala in the limbic system?

Answer 7

• linked to the production of aggressive behaviour
• fMRI showed increased activity during aggressive responses

Question 8

Evaluating limbic system: cats aggression towards rats

Answer 8

+ Egger and flynn: electrically stimulated an area of the hypothalamus to see cats show aggression towards rats
- stimulating different areas of the amygdala would either increase of suppress aggression
- hypothalamus produces aggressive behaviour
- different areas of amygdala regulates aggression
- BUT may not be able to generalise findings to

Question 9

Evaluating limbic system: 14 year old girl, aggressive behaviour and fits

Answer 9

+ summer (2007): case study with 14 year old girl w extreme aggression and epileptic fits
- tumor pressing on amygdala
- after removal her aggression levels became normal
- tumor stimulated amygdala causing aggression
- BUT just a case study, other factors could’ve been causing the aggression

Question 10

what is the serotonin deficiency hypothesis?

Answer 10

• lower than normal serotonin in the orbitofrontal cortex
• less self control over the limbic systems aggressive impulses
• lower levels of 5-HIAA (byproduct of serotonin breakdown) in the spinal fluid of more aggressive people= low levels of serotonin in the brain

Question 11

Evaluating testosterone: Wagner (1980) mice injected with testosterone

Answer 11

+ measured aggression in mice by how often they bit the target
- males bit more frequently than females
- sex diff disappeared after castration
- males injected with testosterone it came back
- testosterone injections also increased female mice’s biting frequency
- level of testosterone is directly connected to the expression of aggressive behaviour

Question 11

General evaluations: Biologically reductionist theory

Answer 11

• can produce effective biological interventions to reduce aggression
• unlikely to be full explanation for aggressive behaviour
• biology may provide an emotional trigger, but may have social psychological factors like SLT

Question 11

Evaluating serotonin: Tryptophan in food

Answer 11

+ tryptophan in food is needed by the body to produce serotonin
- study used acute tryptophan depletion to reduce serotonin the the brain for experimental group
-measured response to seeing angry face in fMRI
- found less communication between amygdala and the frontal cortex
- scored high on aggression questionnaire
- lack of serotonin reduces the frontal cortex’s ability to control aggressive impulses in the amygdala

Question 12

Evaluating serotonin: Tryptophan in food, how the study was high in validity

Answer 12

• randomized
• double blind placebo controlled method
• data analysed= fMRI readings
• study has very high validity
• BUT the use of a aggression questionnaire at not accurately measure aggression

Question 13

General evaluations: Biologically deterministic

Answer 13

• being aggressive due to anatomy Is Biologically deterministic
• judge could use neural and testosterone abnormalities in mitigating factors in violent crime
• people with those agencies may feel as thought they have no power to resist aggressive impulses

Question 14

General evaluations: socially sensitive implications

Answer 14

• this area can have potential negative consequences for people it studies
• if aggressive criminality is linked to limbic implications, people could be suspicious those who have this implication, even if they have never committed a crime

Question 15

General evaluations: highly controlled studies

Answer 15

• highly controlled studies using careful objective biological measurements in studies on this theory of aggression
• reduce the potential for bias in studies that use self report techniques
• high internal validity