Biological pyschology - aggression Flashcards
role of the limbic system
limbic system handles memory but also raw appetites and desires - sleep, hunger, aggression and sex
role of amygdala
role in how an organism assess and responds to environmental threats and challenges
evidence of association between amygdala and aggression
Emil Coccaro et al
- studied people with intermittent explosive disorder (IED), who had a tendency of having outburst of aggression
- participants brain were scanned using fMRI whiled they viewed faces, IED pps showed high levels of activity in the amygdala when viewing angry faces compared to non IED participants
role of orbitofrontal cortex (OFC) in the prefrontal cortex
- plays a role in higher cognitive functions e.g decision making
- plays a role in self control, impulse regulation, and inhibition of aggressive behaviours
evidence that does not support the association with OFC and aggression
Raine et al (1997)
- used PET scans to study NGRIs and found greater glucose metabolism in the amygdala but low activity in the prefrontal cortex, including the OFC compared to the group of controls
role of serotonin in aggression
- decreased serotonin reduces self control, leading to more impulsive behaviour including aggression
- normal levels of serotonin increases self control, so less aggression
evidence linking serotonin and aggression
Matti Virkkunen et al (1994)
- compaed levels of a product of serotonin 5-HIAA from fluid in the spinal cord in violent and non violent offenders
- found that the levels were lower in violent offenders
role of serotonin
slows down neuron transmission
role of dopamine
- has an inhibitory effect in some areas of the brain and exhibitory in others
- regulates motivated behaviour and our experience of reward
- linked to feelings of pleasure and seems to play a part in addiction
how does dopamine cause aggression
when it interacts with serotonin
types of NEUROTRANSMITTERS LINKED TO AGGRESSION
- serotonin
- dopamine
strength of brain structures relating to aggression
- lots of research associating the amygdala and aggression
such as:
Emil Coccaro et al - studied people with intermittent explosive disorder (IED), who had a tendency of having outburst of aggression
- participants brain were scanned using fMRI whiled they viewed faces, IED pps showed high levels of activity in the amygdala when viewing angry faces compared to non IED participants
- which is meaningful as angry facial expression is an ecologically valid sign of threat
weakness of brain structure and aggression
- studies on neural influences on aggression only shows a correlation this means that it is impossible to establish whether a particular rain structure is actually the cause or effect of aggressive behaviour or whether a third variable is involved
what is evolution
the changes in inherited characteristics in a biological population over successive generations
why does genetic variation occur
- combination of genes from parents
- spontaneous mutations in genes
why is variation important
- when there are less resources individuals who’s variations caused them to posses characteristics that help them survive and reproduce , pass genes onto the next generations compared to those who have the disadvantaged gene so they cannot survive or reproduce so they become extinct.
what causes natural selection and what is its outcome
- natural selection is due to the survival of genes and it happens when there is a competition for scarce resources
- the most useful genes are kept in the population and overtime become more frequent
- the outcome of natural selection is adaption (the survivors are better suited to life in the current environment than the predecessors)
what is natural selection
- the process that explains evolution where inherited traits that enhance an animals reproductive success are passed on to the next generation, whereas animals without traits are less successful at reproduction and their traits are not selected
what is sexual selection
an explanation for partner preference, that attributes or behaviours that increase reproductive success are passed on and become exaggerated over succeeding generations of offspring
why is sexual selection important
as some characteristics and behaviours are adaptive as the provide an advantage over competitors for reproductive rights
aggressive characteristics that enhance survival and reproduction in humans
- guarding your partner - mate retention strategies are often aggressive behaviours men use to keep their partners and prevent them from leaving. According to (Wilson and Daly 1966) direct guarding is male vigilance over partners behaviour
- guarding your offspring - human parents direct aggressive acts towards other people who threaten their children. Aggression protects parents investment (their child) and is one of the very few situations in which females behave as aggressively as males.
strength of evolutionary theory
it can explain gender differences in aggression
- cooperative females are likely to be naturally selected because cooperation protect them and their offspring as a group. In contrastmales are naturally selected because they make better hunters. This supports the explanations for gender differences in aggression and increases the validity of the theory of natural selection
weakness of evolutionary differences
- cannot explain cultural differences in aggressive behaviour
- For example amongst the !Kung San people of the Kalahari in southern Africa, aggression is discouraged from childhood and is therefore rare. In contrast the Yanomami of Venezuela and Brazil have been described as the fierce people and aggression is an accepted behaviour to gain status in their structural society. Therefore aggression is not universal which suggests innately determined behaviour can be outweighed by cultural norms.
application of evolutionary theory
- buss (1989) found in 33 countries that males preferred younger more attractive women, this enhances their reproductive success before such women are fertile. Females preferred older, wealthier and ambitious or hard working men which is likely to reproductive success because their children are well supported. This supports evolutionary theory because it shows that the prediction from the theory are upheld by evidence.
what was the metaphor Sigmund freud used to explain the unconscious part of the brain
iceberg metaphor -
The conscious mind is that part of the mind we are aware of. It can be compared to the part of an iceberg that is above the water.
The pre-conscious mind is the part of the mind we are occasionally aware of. It can be compared to the part of the iceberg that is below the water-line but still visible.
the unconscious is the largest part, below hidden from the surface
what does the unconscious brain do (freud)
- contains thoughts, memories and desires of which we are unaware
- plays a role in aggressive instincts as even though we may not be thinking aggressively our behaviour may be influenced by aggressive urges that our hidden in our unconscious