(Abby) bio pack 3- aggression Flashcards
what is aronsons definition of aggression
- an intentional action aimed at doing harm or causing pain
- either physical or verbal
what is the limbic system responsible for
- emotions
- forming memories
- motivation
what is the amygdala
- within the limbic system, enables instinctive emotions such as happiness and anger
- connects to prefrontal cortex meaning when were exposed to threatening stimuli amygdala is activated, increasing emotional arousal and fight/flight response occurs
- therefore has a role in reactive aggression
whats the role of the hypothalamus
to maintain homeostasis
what evidence is there from case studies of brain damaged patients to support the role of the limbic system in aggression
- Charles Whitman was a student at texas uni and an ex marine
- he killed his wife and daughter and then killed 14 others and wounded another 32 during a shooting on campus
- after his death he was found to have a cancerous tumour in the hypothalamus & near the amygdala
what evidence is there from brain scanning (FMRI) to support the role of the limbic system in aggression
- coccaro et al (2006) studied a group of people with intermittent explosive disorder (IED) to show that an overreactive amygdala is associated with high levels of reactive aggression
- they showed p’s a threatening stimuli and measured brain activity using FMRI scans
- compared to control group, p’s with IED had greater activity in amygdala and less in prefrontal cortex
what are some of the executive functions of the prefrontal cortex
- planning, problem solving, social judgement, decision making and regulation of emotional response
how does the prefrontal cortex regulate aggression
- controls reactive aggression impulses that stem from the amygdala
- it inhibits us from automatically reacting to threats and allows us to think about an appropriate course of action
- when we do stop and think we can still act aggressively, mainly when we have a goal in mind- called pro-active aggression
what evidence is there from case studies of brain damaged patients to support the role of the prefrontal cortex in aggression
- phineas gage suffered accidental damage to his prefrontal lobes when a bolt when through his cheek and up through his eye
- he recovered physically but psychologically he became a different person
- he went from a sober, quiet man to an aggression drunk and showed poor social judgement
what is the role of the neurotransmitter serotonin and how is it linked to aggression
- serotonin pathways are involved in the regulation of psychological biological functions like mood, anger, aggression and arousal
- low levels of serotonin are linked with increased tendency towards impulsive and aggressive behaviour
what evidence is there from brain scanning (CAT) to support the role of the prefrontal cortex in aggression
- grafman et al (1966) studied veterans of the vietnam war using CT scans
- found that veterans with structural damage to there prefrontal cortex were more aggressive to those without
what evidence is there for the role of serotonin in aggression
- clinical drug studies
- antidepressants which increases levels of serotonin (SSRIs) also tend to reduce irritability and impulse aggression
- suggests that increases serotonin levels lead to reduced aggression levels
what happens when there is low levels of serotonin
high aggression and its usually reactive as no longer inhibiting the fight or flight response of the amydala
who was raine
an expert witness
what was the aim of raine et als study
using PET scans to detect if there are brain abnormalities in murderers who pleated NGRI
who was in the experimental group of rain et als study
- ‘seriously dangerous individuals’
- 41 individuals charged with murder or manslaughter
all pleaded NGRI - mean age was 34.4
what was the sample of rain et als study
- 2 groups
- 41 people (39m, 2f) in each group
what did raine et al hypothesise
that p’s pleading NGRI would show brain dysfunction in areas of the brain previously associated iwth violence like the amygdala
who was in the control group of rain et als study
- matched experimental group on age, sex and psychiatric illnesses such as schizophrenia
- experimental design is matched pairs
- they were further screened for there mental and psychiatric health
what was the research method of rain et als study
- lab experiment using matched pairs design
- main IV as whether the p had committed murder or not
- DV were the results of the PET scans
- design is refered to quasi as researchers dont have complete control over the IV
what was the procedure of raine et als study
p’s were required to perform a CPT (continuous performance task) involving p’s staring at a screen while various blurred symbols appear
- p’s had to press a button when a particular symbol appeared thus requiring constant attention
- they did it for 10 mins as a practise trial
- a radioactive glucose tracer was then injected into the p
- after another 32 mins of the task the p’s brains were PET scanned to detrrmine the glucose metbolic rate
what were the results of rain et als study
- support was found for the hypothesis
- the NGRI group had brain abnormalities in areas that had previously been implicated in violent behaviour
- there were abnormal asymmetrical levels of limbic sytem activity compared to the control in the amygdala (right hemisphere higher than control, left lower
what is one reason for raine et als conclusions
- the abnormal fucntioning of the amygdala which is responsible for emotional processing results in the murderers being fearless which increases the chances of violent behaviour
what conclusions were drawn from rain et als study
- reduced activity in certain aras of the brain like the prefrontal cortex togther with asymmetries of activities in structures of the limbic system such as amygdala could predispose a person towards violent behaviour
what areas of grave are strong for raine et als study
- generalisability
- reliability
- applications
- validity
- ethics
what areas of grave are weak for raine et als study
- generalisability
- validity
- ethics
how is generlisability a strength for raine et als study
- large sample of violent offenders used
- sample more liekly to be representative of target population
- seen with 41 violent offenders used
- therefore results on brain disfucntion probably give some valid information on this type of violent offender and causes of there behaviour
how is generalisability a weakness for raine et als study
- sample consited of mainly men
- less likely to be representative of target population of female violent offenders
- seen in study with 41 murderers only 2 of which are female
- however most extremaly violent offenders are male so it may give valid info on brain disfucntion in the relatively small group of people
how is reliability a strength for raine et als study
- reliability is high as a whole
- because standardised procedures and equipment were used on every p increasing replicability
- e.g they had 10 mins practise before they were all given the same CPT for32 mins and then were all PET scanned
how is validity a strength for raine et als study
- some varibales were well controlled
- strength as it increases accuracy by reducing confounding varaibles that could affect outcome
- e.g p’s didint take any medication for 2 weeks leading up to experiment to enure that mediaction didnt impact the results
how are applications a strength for raine et als study
- study is useful for society as it sugests that pre-dispositions for commiting violent criminal acts coul be identified using PET scans
- useful as violent offenders could be predicted and early interventions could take place
- e.g PET scans showed violent offenders had abnormal brain activity in structures like the PFC and amygdala compared to control
how is validity a weakness for raine et als study
- study is reductionist as it focuses on brain structure and activity as an explanation of violent criminal behaviour reducing validity
- because it is limited in its explanation of the causes of violent aggression
- e.g it dors not give a reason for the activity detected in the PET scans
- however reductionism is a valuable characteristic of the scientific approach as it allows for raine to fvous on the biological varaible
how are ethics a strength for raine et als study
- study was approved by the ethics committees
- means ethical guidelines were largely followed
- e.g there was no deception and limited harm to the p’s and all gave consent
- however although consent was given it is possible that p’s may not have been fully aware of the implications of the consent
how are ethics a weakness for raine et als study
the p’s were not always fully protected from harm
- means that although ethical guidelines were followed there were still costs for the p’s
- e.g all p’s couldnt take meds for 2 weeks prior to experiment
- however these problems may be outweighed by the p’s hope to have the NGRI claim accepted
what was macoby and jacklins (1974) study
- undertook dozens of lab ad field experiemtns in various cultures
- they concluded that boys re consistently more aggressive than girls
- one reason is males produce more testosterone than females and are exposed to more in the womb
what are the issues and debated for raines study
determinism
- those with a smaller amygdala and low activity in PFC tend to be more aggressive because hormones are less regulated
how is testosterone linked with aggression
- high levels of test are linked with high levels of aggression
- test may infuence serotonin levels in areas of the brain involved with aggressive reactions such as amygdala and PFC
what are the 4 peices of supporting research for the role of testosterone in aggression
- dabbs et al (1987)-> saliva of prisoners
- dabbs et al (1995)
- olweus et al (1980)-> boys impatience
- wagner et al (1879)-> aggression in mice
what is cortisol and how is it linked with aggression
- its a hormone produced inthe adrenal glands and is responsible for managing stress levels
- normal cortisol level seems to inhibit aggressive behaviour while low cortisol is linked with aggressive behaviour
- cortisol does not have a direct affect on aggression as high cortisol inhinbits test so lnhiits aggression
name the study used to support cortsiol and aggression
- Barzman et al (2013) -> hormones in saliva of 7-9 yr old boys in psychiatric hospitals
what are the strengths when evaluating hormones as an explanation of aggression
-scientific credability
- supporting evidence
- applications
what are the weaknesses when evaluating hormones as an explanation of aggression
scientific credability
- reductionism
how can evolution be used to explain gender differences in behaviour
- wilson and daley proposed status competition as a way of explaining the evolutionary advantage of male aggression
- this means males will partake in risky activities even if they involve the risk of serious injury or death, due to females being attracted to aggressive risk takers
- by taking part in these activites they are competing at a higher status than other males, iincreasing there chance of winning a high value rate and reproducing
what evidence is there to support status compeition
- wilson and daly analysed data from police homicide records and found that most were commited by young unmarried males
- most homicides involved conflict caused by retaliation, showing of and jealousy
what are the strengths of using evolution to explain aggression
- scientific credability is high of the original theory
- supporting evidence is extensive and wide- ranging
what are the weaknesses of using evolution to explain aggression
- scientiic credibility when the theory of evolution is applied to behaviour is lowered
- reductionism
- determinism
what occurs in twin studies
- monozygotic (identical) twins and dizygotic (non-identical) twins are compared
- if there is a genetic (nature) contribution to a specific behvaiour, MZ would be expected to be more similar (have higher concordance rates) than DZ twins on this ‘trait’
what occurs in adoption studies
- concordance rates between the adoptee and the adopted parents for a particular trait are compared to the concordance rates between the adoptee and the biological parents
- rationale same as in twin studies in the adoptee- biological parents indicating that the trait is affected by genetics (nature)
what was the aim of gottesman and shields (1966) experiment
- to see whether schizophrenia had a genetic basis
- they examined records of patients in a psychiatric hospital over a 16 year period
what was the sample of gottesman and shields experiment
- identified 57 schitzophrenic patients that were one member of a twin
- they tracked down the other twin for each participant
- 24 of the twin pairs were monozygotic and 33 were dizygotic
what data collection methods were used in gottesman and shields experiment
- hospital notes
- self report questionnaires
- self report interviews
- personality testing
- tests to measure disorder thinking
who was the proband in gottesman and shields experiment
the patient who was initially admitted to the hospital
what were the 4 categories each proband and their twin were put into in gottesman and shields experiment
- 1) both the proband and co twin had been hospitalised and categorised with schizophrenia
- 2) both had hospitalisation but the co twin had been given another diagnosis related to schizophrenia
- 3) the co twin had some psychiatric abnormality but nothing related to schizophrenia
- 4) proband had schizophrenia but co twin was clinically normal
what were the results of gottesman and shields experiment
- concordance rates were higher for both MZ and DZ twins for severe schizophrenia compared to mild schizophrenia
- concordance rates were higher in females compared to males (both MZ and DZ)
- concordance for severe schizophrenia was higher in MZ (77%) than DZ (22%)
what are the conclusions drawn from gottesman and shields experiment
- schizophrenia does have a biological basis as the chance of developing schizophrenia appears to be influenced by a persons genes
- not totally caused by genes as concordance wasnt 100% in MZ, therefore genes are a risk factor but environmental triggers are necessary
why are adoption studies better than twin studies
- in twin studies each twin pair grows up in the same environment when growing up
- adoption studies compare MZ and DZ twin pairs that were separated at birth and raised at different environment
- adoption studies can also look at non-twin children that are adopted
what was the aim of Ludeke et als adoption study
- to determine whether peoples attitudes could be influenced through there genes
what is the procedure of Ludeke et als adoption study
- 66 MZ twins and 53 DZ twins that were separated at birth and reunited later in life
- all members of Minnesota’s study of twins reared apart group
- filled in various self report methods to determine attitudes towards traditionalism
what were the results found in Ludeke et als adoption study
- strong positive correlations found across all scales of MZ twins
- only conservatism measured highly for DZ twins
what are the conclusions of Ludeke et als adoption study
- genes do have an influence on peoples attitudes towards traditionalism
- confident this is not due to twins having same environment growing up as they were separate
what is one strength of twin studies
- high scientific credibility
- unique research design allows them to empirically study the nature nurture on human behaviour
- strength as its provides lots of objective, quantitative data in support of the role of genetics and/or the environment in certain behaviours
-e.g gottesman and shields found that concordance rates for severe schizophrenia is higher in MZ twins (75%) than DZ twins (22%)
what is one weakness of twin studies
- scientific credibility is lowered by confounding variables
- in twin studies each twin pair shares the same environment when growing up
- weakens validity as data ono genetics may be confounded as researchers cant be sue that the environment isnt also influencing the behaviour
- eg gottesman and shields cant rule out that the similarities are not due to environmental factors
what is one weakness of adoption studies
- scientific credibility is lowered by confounding variables
- studies do not account for adoptive families choosing children due to their similarities to the biological families
- child may also have spent time with their adoptive families before adoption
- weakness as it means researchers cant be sure that any results showing genetic influences on behaviour are completly accurate because upbringing may be a confounding variable
- reducing validity
what is the alternate explanation to the biological approach
- freud’s psychodynamic explanation of aggression
what is one strength of adoption studies
- scientific credibility is high in adoption studies
- allow for clear isolation of environmental influences
- particularly true in cases where adoption studies use MZ and DZ twins that have been separated at birth and then adopted
- e.g ludeke et al findings allowed them to suggest that genes have an influence on peoples attitudes towards traditionalism
what is the key assumption of freud’s psychodynamic explanation of aggression
- our awareness is in layers, so much of what we think and feel, and most of what motivates us is in the unconscious mind
what are the 3 structures of the mind according to freud’s psychodynamic explanation of aggression
- conscious
- pre- conscious
- unconscious
describe the ID, EGO and super EGO
- ID- born with a mass of pleasure seeking desires and operates on the pleasure principle for immediate gratification
- EGO- operates on the reality principle, controls desires for ID, maintains balance between ID and super EGO
- super EGO- we take on ethics of other people, operates on morality principle, provides us with a conscience
what are the 5 defence mechanisms
- displacement
- denial
- repression
- projection
- regression
what is the eros
- motivates us to live, love and create new experiences and ideas
what is the thanatos
- the death instinct and is a destructive drive to bring us back to the inorganic state
how do you control aggression according to freud’s psychodynamic explanation of aggression
- catharsis
- the process of releasing negative energy from the mind
what are the 5 stages of psycho sexual development according to freud
- oral stage
- anal stage
- phallic stage
- latency stage
- genital stage
