Aggression- paper 3 Flashcards
Describe Paper- Maclean’s limbic system theory of aggression.
The limbic system contains: The hypothalamus, amygdala, parts of the hippocampus, cingulate gyrus and parts of the thalamus.
Plays a key role on whether an individual responds aggressively to external stimulus or not.
The reactivity of the amygdala is a predictor of aggressive behaviour.
Describe Gossip et al’s study into aggression.
The study was of the activity of the amygdala. Ppts were subject to mild provocation in a lab- based game to provoke aggression.
It was found that when ppts reacted aggressively there was a sudden increase in amygdala activity, measured using an fMRI.
These ‘spikes’ where less drastic when benzodiazepines were taken, which suppress the ANS, and less aggression was displayed.
Describe neural mechanisms in relation to aggression.
Contains the orbitofrontal cortex and serotonin.
Serotonin has widespread inhibitory effects throughout the brain and so slows/ dampens neural activity. Normal levels of serotonin in the orbitofrontal cortex are linked with reduced firing of neutrons and is associated with greater self control.
Decreased serotonin disrupts this mechanism reducing self control and leading to an increase in impulsive behaviour including aggression.
Describe Virkkunen et al’s research into aggression.
The research was into the relationship between serotonin and aggression.
They compared levels of serotonin breakdown product in the cerebrospinal fluid of violent impulsive and violent non-impulsive offenders.
They found that levels were significantly lower in the impulsive offenders, supporting the idea that aggression is linked to a disturbance in serotonin levels.
Describe how testosterone links to aggression.
Testosterone is responsible for the development of masculine features and it also has a role in regulating social behaviour via its influence on certain areas of the brain implicated in aggression.
The difference in males and females testosterone levels are thought to account for males being generally more aggressive than females. Males become more aggressive to each other at a time in development when testosterone is at its highest (after 20 yrs old) (Daly and Wilson).
Describe Giammanco et al’s study into testosterones affect on aggression levels.
Recorded biting rates of male rats before castration, after castration and after being injected with testosterone. The results showed a significant decrease after castration and then an increase almost to original levels after being injected with testosterone.
Describe Dolan et al’s study into testosterones affect on aggression levels.
Found similar finding to Giammanco’s study but with humans.
60 male offenders in a maximum security hospital who has a personality disorder or histories of impulsive violent behaviours were used for the study.
The researcher found a positive correlation between testosterone levels and aggressive acts.
Describe the difference between proactive and reactive aggression.
- Proactive is ‘cold blooded’/ instrumental aggression. A planned method of getting what you want.
- Reactive is ‘hot blooded’ aggression. An angry and impulsive response that is accompanied by physiological arousal.
Describe what the MAOA gene is.
The MAOA gene controls the production of the enzyme monoamine oxidase A (MAO-A).
MAO-A breaks down neurotransmitters after they have been transmitter so that they can be recycled.
Describe the effects of the MAOA-L gene.
A variant of the gene MAOA-L leads to low-activity of the MAO-A enzyme and so abnormal levels of serotonin in the brain.
This leads to a MAO-A deficiency in brain areas linked to aggression.
Describe Brunner et al’s study into the MAOA-L gene.
Studied 29 male members in a Dutch family who were repeatedly involved in violent crime.
They found all had abnormally low levels of MAO-A in their brains and the low activity version of the MAOA gene.
What are the etiological assumptions of aggression?
- Aggression is adaptive.
- Aggression is innate but triggered by environmental stimuli.
- Finding may be generalised from non-human to humans.
What is an innate releasing mechanism?
A biological mechanism activated by an external stimulus.
What are the 6 main features of a fixed action potential? (Lea)
- Stereotyped or relatively unchanging.
- Universal: the same behaviour id found in every individual of the species.
- Unaffected by learning.
- Ballistic: behaviour cannot stop once started.
- Single-purpose: behaviour only occurs in a specific situation and not in any other.
- A response to an identifiable specific sign stimulus.
Discuss the frustration-aggression hypothesis as an explanation for human aggression.
(8 marks)
AO1
-Dollard and Millar- aggression is always caused by frustration and frustration is always the result of aggression.
-frustration equals blocking of any goal-orientated action.
-leads to tension that can only be relieved by an aggressive act, cathartic.
-aggression can be displaced
AO3
-Berkowitz’s (wepon effect) argument that aggression results from other factor too.
-cannot explain aggressive acts that are cold and calculated only reactive.
-contexts of psychodynamic approach (aggressive drives/catharsis) v social learning theory (past aggression being reinforced)
Outline one strength and one limitation of evolutionary explanations of aggression.
(6 marks)
Strength
-evidence support (parallels in animal kingdom)
-consistant findings that show there are differences in aggression between males and females.
-can explain type of aggression (bullying to assert dominance)
Limitation
-difficult to test as evidence is correlational and usually involves self-report.
-represents male behaviour as natural and acceptable behaviour
-implications for treatment of male aggression
