Aggression Flashcards
What are the two types of aggression
- proactive; based on term ‘cold blooded’, a planned method of getting what you want
- reactive; based on term ‘hot blooded’, angry and impulsive, accompanied by physiological arousal
What comes under biological approach for explaining aggression
- neural explanation
- hormonal explanation
- genetic explanation
What is the neural explanation for explaining aggression
- Limbic System
- Neurotransmitters => serotonin
What is the limbic system
- involves structures such as the amygdala, hypothalamus, and hippocampus => implicated in reactive aggression
- plays key role in how an organism reacts to environmental threats
- believed to be a key factor in whether we respond aggressively or not to external stimuli
What are different areas the limbic system connects to
- cingulate gyrus
- prefrontal cortex
What does the limbic system do in relation to the cingulate gyrus
- responsible for focusing attention on emotionally significant events
What does the limbic system do in relation to the prefrontal cortex (simple)
- PFC is involved in forward planning and anticipation of reward
How does the hypothalamus play a role in the limbic system
- responsible for regulation of autonomic nervous system
- regulates responses to emotional circumstances
- damage causes inappropriate aggressive responses
How does the amygdala play a role in the limbic system
- responsible for attaching emotional significance to sensory information
- limbic system believed to be hierarchical with signals being passed from lower systems to high in prefrontal cortex
- feelings are monitored and interpreted in prefrontal cortex, triggering a physical response
How does the prefrontal cortex play a role in the limbic system (detail)
- feelings from amygdala are monitored and interpreted, triggering physical response
- crucial for regulating social behaviour and aggressive responses
- damage to prefrontal cortex would reduce the inhibition of the amygdala resulting in higher levels of aggression
How do neurotransmitters such as serotonin play a role in aggression
- serotonin has a widespread inhibitory effect in brain, slowing down neural activity
- regulates different areas of brain
What are examples of different areas that serotonin regulates
- prefrontal cortex
- frontal areas of brain
How does serotonin regulate frontal areas of the brain
- works on frontal areas of brain to inhibit during of amygdala
- significant as amygdala controls fear, anger and other emotional responses
- thus has a calming influence
- low levels means people cannot control impulsive and aggressive behaviour
How does serotonin regulate the prefrontal cortex
- regulates prefrontal cortex
- therefore lower levels of serotonin affect response to external stimuli
- means person becomes aggressive easily and cannot control responses
- person cannot anticipate risk and therefore impulsively engages in aggressive behaviour
What are examples of positive evaluation points for neural mechanisms in aggression
- Kluver and Bucy (1939)
- Wong et al. (1997)
- Ferrari et al. (2003)
What structures are in the limbic system
- hypothalamus
- thalamus
- hippocampus
- amygdala
- formix
- cingulate gyrus
How is Kluver and Bucy (1939) a positive evaluation point for the neural mechanisms in aggression
- early researchers who removed main areas of limbic system in rhesus monkeys
- amygdala, hippocampus and surrounding cortical areas
- found monkeys displayed a sense of emotional, motor, and vocal reactions which are normally associated with stimuli or situations eliciting fear and anger
- lesioned monkeys also lost social understanding of group hierarchies and tried to fight dominant larger members of group
- research demonstrates importance of limbic system in regulating aggressive responses
How is Wong et al. (1997) a positive evaluation point for the neural mechanisms in aggression
- neural explanations can be shown through neuroimaging such as MRI scans
- Wong undertook MRI scans of 19 violent male criminals in Broadmoor hospital
- compared size of amygdala with 20 ‘normal’ control subjects
- found volume of amygdala was significantly smaller in 19 violent criminals
- supporting role of amygdala and limbic system in aggression
How is Ferrari et al. (2003) a positive evaluation point for the neural mechanisms in aggression
- provided support for role of serotonin in aggressive behaviour
- allowed adult male rats to fight with each other at a specific time for ten days
- on eleventh day, rat wasn’t allowed to fight
- researchers found rat’s dopamine levels rose by 65% and serotonin reduced by 35%
- despite rat not fighting, experience had changed the rat’s brain chemistry
- however question raised whether low levels of serotonin cause aggression or they are a response to aggression being carried out
- cause and effect cannot be established lowering validity
- research still shows complexity of role of serotonin in aggressive behaviour
What are examples of negative evaluation points for neural mechanisms in aggression
- extrapolation
- sample
- Mann et al. (1990)
How is Mann et al. (1990) a negative evaluation point for the neural mechanisms in aggression
- administered drug to 35 healthy adults
- researchers then used a questionnaire to assess aggression levels, which rose for males but not females
- shows gender differences in neural mechanisms
- also demonstrates issue of beta bias that is inherent in neural explanations of aggression
- shows males and females may not be subject to same physiological factors when explaining aggression
How is sample a negative evaluation point for the neural mechanisms in aggression
- lack of population validity
- Wong’s sample was relatively small
- inappropriate to generalise limited findings to wider population
How is extrapolation a negative evaluation point for the neural mechanisms in aggression
- animals used for research to provide evidence for aggression in humans
- differences in physiology questions whether we can extrapolate research findings from animals to human aggressive behaviour
- despite monkeys and humans possessing similar neural structures, we cannot be sure that the processes involved in mediating aggression in humans are the same as those shown in monkeys
What are the hormones implicated in aggression
- testosterone
- progesterone
What is testosterone
- main hormone which decides whether an embryo develops into a male or female
- this male sex hormone is an androgen responsible for development of masculine features
- promotes muscle strength and is responsible for the sex drive
How does testosterone influence aggression
- influence present from young adulthood onwards due to actions in brain areas involved in controlling aggression
- Sapolsky (1998) summarised research evidence in this area by describing how removing the source of testosterone in different species typically resulted in much lower levels of aggression
Who has shown evidence for testosterone causing human aggression
(NEED TO KNOW NAMES)
- Archer (2009) => men are more aggressive than women
- Dabbs (1990) => men have higher concentration of testosterone than women
- Daly and Wilson (1998) => testosterone concentration is highest between 21-35 and there is an increase in male-on-male aggression
- Carre and Olmsted (2015) => claim testosterone concentrations are not static but fluctuate rapidly in context of changes to social environment. Changes in testosterone levels appear to influence aggressive behaviour by increasing amygdala reactivity during the processing of social threat
What is progesterone
- female ovarian hormone which can help increase mood
- acts as a natural antidepressant to lower anxiety
- plays important role in female aggression
- levels vary during ovulation cycle and are lowest during and just after menstruation
Who has researched into the role of progesterone in aggression
- Ziomkiewicz et al. (2012)
- found negative correlation between progesterone levels and self reported aggression
- suggests low levels of progesterone is linked to increased aggression in women
What are positive evaluation points for hormonal mechanisms in aggression
- Wagner (1979)
- Giammanco et al. (2005)
How is Wagner (1979) a positive evaluation point for hormonal mechanisms in aggression
- research support by finding if testosterone was implicated in aggression, especially in non-human animals
- decided to test this theory by castrating mice
- found aggression levels fell
- provided support that testosterone is implicated in aggression
How is Giammanco et al. (2005) a positive evaluation point for hormonal mechanisms in aggression
- reviewed studies
- confirmed role of testosterone in aggression
- e.g. in male rhesus macaque monkeys, there is an increase in both testosterone levels and aggressive behaviour during the mating season
What are negative evaluation points for hormonal mechanisms in aggression
- lack of generalisation in animal studies to humans in research
- furthermore, Wagner’s (1979) research only provides correlational support for cause of aggression as research only demonstrates a relationship between lowered testosterone and lowered aggression
- does not confirm if testosterone is a cause of aggression
- biologically reductionist and deterministic
- however reductionism can be seen as a positive as well
What are genes
- consists of DNA strands
- DNA provides instructions for physical features of an organism
- may impact physiological features
- genes are transferred from parents to offspring
How can the link between genes and aggression be shown
- genetics
- twin studies
- adoption studies
- candidate genes
How do genes influence genotype and what is one study that investigated genotypes
- basic difference in men and women lie in genotype, most have 23 pairs of chromosomes
- XY is male and XX is female
- psychologists investigating aggression believed genetic cause of aggression could lie in Y chromosome
- particularly interested in investigating individuals with XYY genotype => super males
- shown in Court-Brown’s (1965) study who discovered 314 patients had XYY chromosome presentation
- put forward view that these patients remain hospitalised due to increased likelihood of aggressive behaviour
Where do psychologists who study genetic factors of aggression focus on
- focus on examining individuals with normal XY genotype
- psychologists have used selective breeding in animals
- found that aggression is a trait that can be transmitted from parents to offspring
- supports genetic explanation
What is the significance of twin studies in investigating aggression
- research with human subjects has focused on twin studies that have looked at the incidence of aggression displayed by MZ and DZ twins
- MZ share 100% of genes
- DZ share 50% of genes
- differences in concordance rates of aggression between these sets of twins have indicated that aggression has a genetic element
Who has carried out research into twins studies for the genetic factors of aggression
- Coccaro et al. (1997)
- studies pairs of male adult twins who were MZ or DZ
- found concordance rate for aggression defined as a direct physical assault for MZ was 50% and DZ was 19%
- concordance rate for aggression defined as verbal aggression was 28% for MZ and 7% for DZ
- figures high enough suggesting there is a genetic component, although concordance higher for physical
What is the basis behind adoption studies for the genetic factors of aggression
- similarities in aggression between adopted child and biological parent suggest genetic influences are operating
- similarities in aggression between adopted child and adoptive parents suggest environmental influences are operating
Who has carried out research into adoption studies for the genetic factors of aggression
- Rhee and Waldman (2002)
- carried out meta analysis of adoption studies of direct aggression and antisocial behaviour
- found genetic influences accounted for 41%
- research in line with findings of twin studies suggesting role of genetics to be important in aggressive behaviour
How can candidate genes influence aggression
- advances in genetic testing shows specific genes for aggression => MAOA gene
- responsible for production of the protein monoamine axidase
- allows metabolising of noradrenaline, serotonin and dopamine
- gene dysfunction results in these neurotransmitters not being broken down
What happens if candidate genes are not broken down
- if adrenaline isn’t metabolised then too much adrenaline in body
- causes hypersensitivity in fight or flight and individuals may overreact to external stimuli and perceive threat where one does not exist
- increased levels of dopamine also link to aggressive behaviour
- serotonin has calming influence and low levels implicated reduction in control
What happens with low MAOA
- low activity of variant of MAOA gene (MAOA - L) then people likely to be aggressive
- MAOA - L (warrior gene)
- shown by Lea and Chambers (2007) who found this gene was possessed by 56% of New Zealand Māori men compared with 34% of Caucasians
- historically, Māori people have reputation for being ferocious warriors
Table showing consequences of a dysfunctional MAOA gene
What are positive evaluation points for genetic factors influencing aggression
- Coccaro et al. (1997)
- Godar et al. (2014)
- Brunner (1993)
- Stuart et al. (2014)
How is Coccaro et al. (1997) a positive evaluation point for genetic factors influencing aggression
- supports role of genetics and aggression as concordance rate of physical aggression in form of criminal behaviour for MZ twins was higher than DZ
- suggests role of nature plays a strong role in aggression
How is Godar et al. (2015) a positive evaluation point for genetic factors influencing aggression
- refined selective breeding by specifically removing certain genes in mice
- has been done with the MAOA gene
- MAOA selectively bred mice showed increased aggression and also has abnormal levels of serotonin, demonstrating relationship between genes and neurotransmitters
- when mice were given fluoxetine to raise serotonin levels, behaviour returned
- supports role of genetics, especially MAOA
How is Brunner (1993) a positive evaluation point for genetic factors influencing aggression
- link between MAOA -L gene supported
- studied 28 men from large Dutch family who were repeatedly involved in impulsively aggression violent criminal behaviour, such as rape, attempted murder and physical assault
- these men possessed MAOA-L gene
How is Stuart et al. (2014) a positive evaluation point for genetic factors influencing aggression
- studied 97 men who had been involved in severe domestic abuse to their partners
- found most violent men had the faulty MAOA gene
- men engaged in the highest level of physical and psychological aggression and inflicted the worst injuries on their partners
What are negative evaluation points for genetic factors influencing aggression
- Theilgaard (1984)
- twin studies
How is Theilgaard (1984) a negative evaluation point for genetic factors influencing aggression
- undertook research into men with the XYY genotype and found that XYY can cause an increase in height in individuals but not aggression
- shows we cannot make generalisations about aggression as this research is howling no link between XYY and aggression
How is twin studies a negative evaluation point for genetic factors influencing aggression
- may lack validity
- twins share same environment
- however DZ twins may not share same environment to same extent as MZ
- e.g. MZ treated by parents and significant others in same way but DZ may not, especially if they are not the same sex
- means due to MZ twins not only having same genes but also identical environmental experiences may contribute to their aggression instead
What is an ethological explanation
- seeks to understand innate behaviour of animals by studying them in their natural environment
- focus on an ethological explanation is to try and account for behaviour in terms of its adaptive value to the specific species
- ethologists believe that by looking at animal behaviour, this helps understand human behaviour
- e.g. Lorenz (1966) geese
How can aggression be seen from an ethological approach
- aggression is seen as providing an adaptive function by ethologists
- aggression is seen in all animal species and is believed to be an innate behaviour
- if behaviour is innate, evolutionary psychologists propose behaviour must be beneficial for organism
- aggression as a behaviour can help survival, as aggression can protect resources
- can establish dominance hierarchies
What did Lorenz (1966) propose for aggression
- aggression in animals is often ritualistic
- argued is more adaptive than direct aggression, as symbolic aggression would help ensure organism was not harmed
- if organism sustained an injury as part of aggression, this could impair ability to reproduce
- therefore, ritualistic aggression such as teeth baring would have effect of deterring an opponent without physical harm being caused
What does the ethological theory propose
- aggression can be result of an evolved automatic biological response in the brain
- believed animals have built in neural structure which when exposed to specific stimuli, will cause release of an automatic behaviour response
How do inbuilt biological structures link to aggression according to the ethological theory
- inbuilt biological structure or process is called the innate releasing mechanism (IRM)
- environmental stimulus triggers IRM
- IRM releases specific sequence of behaviours
- consequential aggression behavioural sequence is called the fixed action pattern (FAP)
What are the main features of Lea’s (1984) FAP
- stereotyped, or relatively unchanging sequences of behaviours
- universal, because same behaviour is found in every individual of its species
- unaffected by learning, same for every individual regardless of experience
- ballistic, once the behaviour is triggered, it follows an inevitable course an cannot be altered before it is completed
- single purpose, behaviour only occurs in a specific situation and not in any other
- response to identifiable specific sign stimulus
What are positive evaluations points for ethological explanations for aggression
- Tinbergen (1951) undertook a experiment with male sticklebacks
- species of fish is territorial and aggressive
- in mating season, they develop red spot on underside
- Tinbergen observed male sticklebacks will attack another stickleback theorising red spot initiated aggressive behaviour
- to test, he presented male sticklebacks with a wooden model; if wooden model had red spot, stickleback would attack
- without red spot, stickleback would not react and there was no aggression displayed
What are negative evaluations points for ethological explanations for aggression
- Nisbett (1996)
- Goodall (2010)
- modal action patterns
How is Nisbett (1996) a negative evaluation point for the ethological approach
- one weakness of explanation is it assumes behaviour is innate so is uniform across all cultures
- found in lab experiment when South American white males were insulted they were more likely to respond aggressively than white North American males under same conditions
- demonstrates cultural differences would be problematic for ethological explanation to account for as there was a high variation in aggressive responses
How is Goodall (2010) a negative evaluation point for the ethological approach
- animal kingdom aggression is not always ritualistic
- studied chimpanzee behaviour for over 50 years
- observed chimpanzees that wages a brutal war against neighbouring chimpanzees and slaughtered whole group
- referred to this type of gang behaviour as systematic slaughtering by a stronger group
- this aggression is hard to explain from an ethological standpoint as the risk of injury to the attacking group is high and thus does not appear to be adaptive behaviour
How is modal action patterns a negative evaluation point for the ethological approach
- not all fixed actions patterns are fixed
- some evidence that learning and environmental factors can create variation within a species
- may be more appropriate to discuss modal action patterns rather than FAPs
- MAPs are behaviours that are instinctual but differ from one individual within the species compared to others
- difference may be due down to result of selective breeding of characteristics
What does the evolutionary approach say about aggression
- focus on changes in species over millions of years based on idea of natural selection
- behaviour that enhances survival and ultimately successful reproduction is perpetuated
- therefore makes sense aggression is a behaviour aiding survival and therefore ben passed on through generations
What are the different evolutionary explanations for aggression
- sexual jealousy
- bullying
- warfare
What is the evolutionary explanation of sexual jealousy
- major motivation explaining aggression in males from evolutionary perspective
- occurs due to man can never be sure whether they are father of their child => paternity uncertainty is result of cuckoldry
- therefore any investment in offspring who does not share male’s genes is waste of resources
- in fact, contributes to survival of male rivals genes and leaves father with fewer resources to invest in his own offspring
What is the significance of men in the evolutionary past in sexual jealousy
- men who could avoid cuckoldry were more reproductively successful
- psychological mechanisms have evolved to increase anti cuckoldry behaviour in males
- thus sexual jealousy is experienced more strongly in males than females
- leads to aggressive strategies men employ to keep partners and prevent them from straying
- male retention strategies
What are mate retention strategies in sexual jealousy
- direct guarding => male is vigilant over partners behaviour
- negative inducements => issuing threats of dire consequences for infidelity
- physical violence => Wilson et al. (1995) asked women to report mate retention strategies to partners. Measured in terms of extent they agree with statements. Women who did agree with statements were twice as likely to have experienced physical violence from partners => 73% had required medical attention and 53% feared for their lives
What is the evolutionary explanation of bullying in aggression
- bullying occurs due to power imbalance => most powerful individual uses aggression deliberately and repeatedly against weaker person
- researchers traditionally viewed bullying as maladaptive behaviour
- however evolutionary ancestors may have used bullying as an adaptive strategy to increase chances of survival by promoting their own health and creating opportunities for reproduction
How is male bullying significant as an evolutionary explanation for aggression
- Volk et al. (2012) argued characteristics associated with bullying behaviours are attractive to females => dominance, acquisition of resources, and strength
- bullying has benefit of warding off potential rivals
- bullying would be naturally selected because males would have greater reproductive success
- may be beneficial for bully’s health as it was found teenage boys who gain reputation for being tough are less likely to experience aggression towards them as others avoid them
- benefits health as they do not experience stress of bullying (Sapolsky, 2004)
How is female bullying significant as an evolutionary explanation for aggression
- bullying often takes place within relationship
- method used to control partner and prevent infidelity which means they continue to provide resources for future offspring
- such behaviours would be naturally selected due to enhanced reproductive success (Campbell, 1999)
What is the evolutionary explanation of warfare in aggression
- Smith (2007) claims human warfare originated not only to gain valuable resources but also to attract mates and forge intragroup bonds
- displays of aggressiveness and bravery are attractive for females => shown in past where male warriors in traditional societies had more sexual partners and children => direct reproductive benefit
- aggression in combat also increases status leading peers to respect them