Aggression Flashcards
what did coccaro et al find out in regards to twin studies
in adult twin pairs nearly 50% of the variance in direct aggressive behaviour could be attributed to genetic factors
what did miles and carey find in regards to genetic factors
meta analysis of 24 self report twin and adoption studies based on aggressive tendencies
there was a strong genetic influence that could account for as much as 50% of variance in aggression
strongest genetic influence found among older individuals
what is MAOA
a gene that produces protein that regulates the metabolism of serotonin
low levels of MAOA link to more violent and aggressive crimes
what do low levels of serotonin cause
impulsive and aggressive behaviour
what is the evidence for a genetic effect of aggression
14,000 studies of adoption in denmark found that a significant amount of adopted boys with criminal convictions had biological parents (mainly fathers) with criminal convictions
what did rhee and waldman find in regards to genetic influence on aggression
meta analysis of 51 twin and adoption studies concluded aggression and anti social behaviour is largely a product of genetics
what did caspi et al find in regards to the MAOA gene (AO3)
500 male children
children with low levels of MAOA were significantly more likely to grow up and exhibit anti social behaviour but only if they had been mal treated
maltreated children with high levels of MAOA didn’t display such behaviour
(diathesis stress model)
where are low levels of MAOA more likely to be found
in populations with a history of warfare eg tribes
what is desensitisation
media violence can lead to aggressive behaviour by removing the anxiety around violence
(the more televised violence a child watches the more acceptable aggressive behaviour becomes to them)
what is an indication of desensitisation
reduction is psychological arousal (heart rate and skin conductance) when individuals are exposed to real violence after being repeatedly exposed to media violence
what are characteristics of desensitised individuals
less likely to notice violence irl
feel less sympathy for victims of violence
less negative attitudes towards violence
what is disinhibition
exposure to violent media legitimises the use of violence irl because it undermines the punishments that usually cause inhibition of such behaviour
what are the immediate effects of observing violence on tv or a computer game
psychological arousal which leads to greater probability of behaving aggressively
inhibitions are suppressed by the drive to act
what are the effects of observing media violence in the long term
gives the message that violence is a part of everyday life as it is justified or left unpunished on tv
viewers guilt/ concern about consequences is also reduced so child feels less inhibited about being aggressive
how can gender differences influence aggression (AO3)
most studies are carried out on men (gender bias) beta
MAOA gene is most likely linked to X chromosome when men inherit 1 X from their mother they are more likely to be affected whereas women are generally unaffected and therefore prevents expression (alpha bias)
why is it difficult to establish a genetic link with aggression (AO3)
- more than one gene usually contributes to a given behaviour
- there are also non genetic influences that cause aggression
- may be a gene- environment interaction
what are methodological issues with genetic factors in aggression (AO3)
studies have relied on self report or parental reports of aggressive behaviour (can be unethical to directly test it)
observations can show less genetic contributions
difficult to do it reliable
evidence for testosterone causing aggression
men are more aggressive than women and have much higher testosterone concentrations than women
testosterone conc is at its highest age 21-35 and this is when male on male aggression is highest
dabbs et al measured salivary testosterone and those with highest levels had done primarily violent crimes
how can social environment influence aggression (carre and olmstead)
testosterone concentrations fluctuate in the context of changes to social environment
changes in testosterone levels increase amygdala reactivity during the processing of social threat eg angry facial expressions
what is the role of serotonin in aggression
inhibits the firing of the amygdala which controls fear and anger
low levels of serotonin cause impulsive behaviour, aggression and violent suicide
outline Dabbs et al research into testosterone’s levels
measured testosterone levels in the saliva of 89 male inmates. those with higher testosterone concentration were more likely to be convicted of violent crimes
what is the limbic system
network of subcortical structures in the brain (hypoyhalamus and amygdala) thought to be linked to regulating emotional behaviour such as aggression
7 parts of the limbic system
cingulate gyrus fornix hypothalamus hippocampus amygdala parts of thalamus septal area
what is the amygdala
determines how humans and animals behave in response to environmental threats and challenges (the reactivity of the amygdala is an important predictor of aggression)
outline the procedure of gospic et al’s ultimatum game
proposer offers to split money in a certain way with the responder whilst being connected to an fMRI scanning machine
if they accept the offer they get a share of the money each and if they reject the offer they both get nothignn
what were the results of gospic et al’s ultimatum game
when responders rejected unfair offers there was a heightened response from the amygdala.
if benzodiazepine was taken beforehand it decreases activity of the amygdala and halved the number of rejections (reduced aggression)
what is the role of the orbitofrontal cortex
amygdala operates in tandem with the OFC (not part of the limbic system)
involved in self control, impulse regulation and inhibition of aggressive behaviour
what brain structures does the regulation of aggression involve
amygdala
orbitofrontal cortex (OFC)
connection between the 2
outline Van Goozen et al’s study into aggression in transsexual participants
35 female to male and 15 male to female transsexuals completed questionnaires to assess proneness to aggression. completed the questionnaire before and after receiving hormone treatment (androgens or anti androgens)
female to male- increase in aggression
male to female- decrease
p’s may have been conforming to stereotypes of new gender role but controlling levels experimentally means cause and effect can be established
what is ethology
the study of naturally occurring animal behaviour (can include human behaviour)
Ethologists usually look at a particular behaviour across species
what was lorenz’s theory of aggression
based on animal behaviour but applied to humans too. he defined it as a fighting instinct directed at members of your own species
an innate tendency triggered by environmental stimuli
how had the idea of the ethological explanation of aggression been observed in red bellies sticklebacks
male sticklebacks develop bright red bellies during breeding season. this stimulates an innate releasing mechanism in other males which triggers specific fighting behaviour
what is the purpose of ritual behaviours
stop confrontations from being fatal eg wolves end a fight by the loser exposing his jugular vein so the winner could kill the rival but the winner doesn’t take any further action.
sport is an example of harmless ritualised aggression release in humans and is important for reducing aggression in society
what is an innate releasing mechanism
proposed innate pathway in the brain that triggers specific fighting behaviour (the fixed action pattern)
what is a fixed action pattern
an instinctive behaviour which is identical across a species
describe the steps of aggression after being triggered by environmental stimuli as described by the ethological explanation
1) urge to engage in aggressive behaviour builds up over time and the internal pressure to be aggressive builds up
2) stimulus triggers aggression
3) if the internal pressure is very high then the strength of the stimulus doesn’t need to be as high
4) stimulus triggers an innate releasing mechanism which sets off a fixed action pattern
what are adaptive functions which aggression may have served in the past
1) gain status or dominance in a group
2) gain resources from others
3) defence
4) defer infidelity in long term mates
why are there differences in aggression between men and women from an evolutionary perspective
in the past young men faced the most competition for mates and the main limit was access to fertile mates
women were mainly limited by access to resources so these different pressure have led to different psychological responses
Outline Buss et al’s study into sex differences in jealousy
(cross cultural questionnaire) P’s were presented with the hypothetical scenario that someone they were in a relationship with became interested in someone else. Asked if they would be more distressed by their partner forming an emotional attachment or having sex
Men reported sexual infidelity to be more upsetting (51% men vs 22% women)
Men’s jealousy is triggered by the threat of uncertainty over the paternity of children produced but women are more threatened by emotional involvement as it could mean being left for another woman (less resources)
evaluate Buss et al’s study into sex differences in jealousy
evidence was consistent across different cultures so suggests the responses are innate rather than learned
hypothetical situation and multiple choice means the validity is questionable
