Aggression P3 Flashcards
define aggresion
a feeling of anger resulting in hostility, violent behaviour & readiness to attack
What is meant by proactive aggresion?
cold-blooded
a planned method of getting what you want
what is meant by reactive aggresion?
hot-blooded
impulsive & angry
accompanied by physiological arousal
biggest cause of social problems
what do the neural mechanisms in aggression consist of?
Limbic system
Amygdala
Orbitofrontal cortex & serotonin
What is the Limbic system?
Papez 1937 & Maclean 1952 linked the limbic system to emotions e.g. aggression
includes the hypothalamus, amygdala & hippocampus
why is the amygdala important?
more reactive amygdala to environmental threats- more likely that aggression will be shown
Support of Gospic 2011
Gospic 2011
used FMRI brain scans
ppts in lab-based game that provoked aggression
aggressive reactions - fast & heightened response by the amygdala
ppts took benzodiazepine - reduces arousal of autonomic nervous system, before the game -> decreased amygdala activity and decreased aggression.
why is the orbitofrontal cortex and serotonin important as a neural mechanism?
normal levels of serotonin in the orbitofrontal cortex inhibit neurons -> reduced firing & linked to greater behavioural self-control
Denson 2012
Virrkunen 1994
low levels of serotonin lead to increased aggresion
Denson 2012
found that decreased serotonin disturbs neural mechanism, reducing self-control and increases impulsive behaviours including aggression
Virkkunen 1994
found that lower levels of serotonin metabolite 5-HIAA in violent impulsive offenders compared with non-impulsive offenders
what does the hormonal mechanism consist of?
Testosterone
Animal studies linking aggression to testosterone
progesterone - low levels linked to aggresion in women
why is testosterone important in the hormonal mechanism?
helps regulate social behaviour via influence on brain areas involved in aggression
high testosterone levels linked to aggression
dolan 2001
Daly & Wilson 1998
Dolan 2001
found a positive correlation between testosterone and aggression in male offenders with histories of impulsively violent behaviour
Daly & Wilson 1998
found that males are more aggressive towards others males at 20+ years when testosterone levels peak
Why are animal studies important in the hormonal mechanism?
AS link aggression to testosterone
Removing testes reduces aggresion in many species
injecting testosterone restores aggressive behaviour (Giammanco 2005)
why is progesterone important in the hormonal mechanism?
low levels linked to aggression in women
Progesterone levels vary in menstrual cycle, lowest during and after menstruation, highest during ovulation
Ziomkiewicz 2012
Ziomkiewicz 2012
found negative correlation between progesterone levels and self reported aggresion
A limit to the neural mechanism, referring to that non-limbic brain structures are also involved
Limbic structures function jointly with the non-limbic orbitofrontal cortex. This is involved in impulse-regulation and inhibition of aggression.
-> Coccaro 2007, claim activity is reduced in psychiatric disorders featuring aggression, this disrupts the OFC’s impulse control function, increasing aggression.
this shows that the neural regulation of aggression is more complex than theories focusing on the amygdala suggest
A strength for the neural mechanism, referring to research into the effects of drugs on serotonin
Berman’s 2009 participants took part in a lab-based game, giving and recieving electric shocks in response to provocation.
Participants who took paroxetine ( enhances serotonin) consistently gave fewer and less intense shocks than a control group.
-> this study is evidence of a casual link between serotonin and aggression
A strength for hormonal mechanisms, referring to support from research with non-human animals.
Giammanco’s 2005, review confirms the role of testosterone e.g. increase in testosterone and aggression in male rhesus macaque monkeys during mating season.
In rats, castration of males reduces testosterone and mouse-killing. Injecting female rats with testosterone increases aggression
these findings show that testosterone plays a key role in aggression in a range of animal species
A limit of the hormonal mechanism, referring to the evidence linking testosterone and aggression is mixed.
Carre and Mehta 2011,
dual hormone hypothesis suggests high levels of testosterone lead to aggression but only when cortisol levels are low.
High cortisol blocks testosterone’s influence on aggression. Cortisol is a hormone that is key to the body’s chronic stress response.
therefore the combined activity of testosterone and cortisol may be a better predictor of aggression than either hormone alone.
what does social psychological explanations consist of?
frustration-aggression hypothesis
SLT
Green 1968 procedure
Male uni students completed a jigsaw puzzle, manipulated frustration
some ppts puzzle was impossible
some ran out of time as a confederate was interfering
some were insulted by the confederate
-participants later had choice to give (fake) electric shocks to the confederates
Green 1968 findings
insulted ppt’s gave strongest shocks on average, then the interfered group and than the impossible-task group
all 3 groups selected more intense shocks than a non-frustrated control group
what is the frustration-aggression hypothesis?
proposed by dollard 1939
frustration always leads to aggression and aggression is always the result of frustration
aggression is a psychological drive
experience frustration when a goal is blocked by an external factor
What does frustration create?
an aggressive drive leading to aggressive thoughts/behaviour (violent outburst, violent fantasy)
What is a catharsis?
expressing the aggressive drive removes the negative emotion, this reduces the drive and makes further aggression less likely
-a psychodynamic concept
What are the causes of frustration?
Abstract e.g. government
too powerful and risk punishment e.g. a teacher who gave you a low grade
unavailable e.g. teacher had left room
aggression is displace onto an alternative - not abstract, weaker and available
what is the ‘weapon effect’?
it shows us cues can make aggression more likely
Berkowitz & LePage 1967 found once students became frustrated in a lab test, they were more likely yo give electric shocks when they could see a weapon next to them
-Shows that frustration only creates a readiness for aggression
What is the ‘negative effect’ theory?
a result of the unclear relationship between frustration anf aggression
Berkowitz argued that frustration is one of many aversive stimuli leading to negative feelings other than anger, like jealousy, despair, helplessness
A Strength for frustration-aggression is support for the key concept of displace aggression
Marcus-Newhall 2000 conducted a meta-analysis of studies where aggression was directed at a human target other than one that caused frustration
- > Provoked participants who could not retaliate against the original source were more likely to aggress against an innocent target than participants who were not provoked
- > > This shows that frustration can lead to aggression against a weaker or more available target
A limitation for frustration-aggression is that aggression may not be cathartic.
Bushman 2002 found that people who vented anger by repeatedly hitting a punchbag became more aggressive rather than less aggressive, doing nothing reduced aggression
- > Using venting to reduce anger is like using petrol to put out a fire, ‘The better people feel after venting, the more aggressive they are’ Bushman
- > > This shows a central assumption of the frustration-aggression hypothesis may not be valid
A limitation for frustration-aggression hypothesis is the link between frustration and aggression is complex.
Frustration does not always lead to aggression and aggression can occur without frustration, the link is not ‘automatic’
- > someone who feels frustrated may behave in a range of different ways e.g. helplessness, someone behaving aggressively may have many reasons to do so
- > > this suggests that frustration-aggression hypothesis is inadequate because it only explains how aggression arises in some situations but no in others.
what does the genetic factors in aggression cover?
twin studies
adoption studies
MAOA gene
Gene-environment interactions
What did twin studies find in relation to aggression?
50% of variance in aggressive behaviour
Coccaro 1997
Coccaro 1997 - twin studies
studied adult male monozygotic and dizygotic twins
for direct physical aggression, the researchers found concordance rates of 50% for MZ twins & 19% for DZ twins
for verbal aggression the figures were 28% for MZ and 7% DZ twins
Why are adoption studies related to aggression?
41% of variance in aggressive behaviour is genetic
similarities in aggressive behaviour between an adopted child and biological parents suggest genetic influences are significant, but similarities w adoptive parents suggest environmental factors
Rhee & Waldman