p3: aggression

Question 1

ao1: what are the two neural mechanisms in aggression

Answer 1

1. the limbic system
2. serotonin

Question 2

ao1: what is the hormonal mechanism for aggression

Answer 2

testosterone

Question 3

ao1: neural (the limbic system) mechanisms in aggression

Answer 3

-neural: the limbic system
-the limbic system, of which the amygdala is part of, is linked to the control of emotions
-amygdalas role - quickly evaluating emotional importance of sensory information and prompting an appropriate response

Question 4

ao1: research for neural (the limbic system) mechanisms in aggression

Answer 4

Panksepp: if certain areas of the amygdala are stimulate electrically, an animal responds with aggression like snarling or an aggressive posture.
-if the same areas are removed surgically, animal no longer responds to stimuli that would have previously led to rage

Kluver and Bucy: discovered the destruction of the amygdala in a monkey who was dominant in a social group caused it to lose its dominant place in the group

Case of Charles Whitman: installed himself on a tower at a university campus with a rifle - shot people dead randomly - supports role of amygdala in aggressive behaviour as a post mortem revealed a large tumor on his amygdale.

Question 5

ao3 for neural (the limbic system) mechanisms in aggression

Answer 5

Pardini et al: longitudinal study of male participants from childhood to adulthood
-some 56 of the participants with varying histories of violence were subjects to mri scan age 26.
-showed participants with lower amygdala volumes exhibited higher levels of aggression and violence
-this remained even after other confounding variables were controlled
-amygadala therefore may play an important role in evaluating emotional importance of sensory info, lower volume compromises this ability and makes violent response more likely

Question 6

ao1: the role of serotonin in aggression mechanisms

Answer 6

serotonin is a neurotransmitter
-carrys electrical impulses around brains network of impulses
-acts as chemical carrier, transferring messages across synaptic gap between neural connections
-calming, inhibitory effect in neural firing in the brain
-thought to reduce agressive behaviour by inhibiting responses to emotional stimuli that might otherwise lead to aggressive response
-lower levels = reduce this ability, = increase in impulsive behaviour, aggression and violent suicide

Question 7

ao1: serotonin studies/application for hormonal mechanisms in aggression

Answer 7

Raleigh et al: vervet monkeys
-used diet to manipulate levels of serotonin in their brains
-those that fed on diets high in tryptophan (increases levels of serotonin) showed decreased levels of aggression
-support for link betweeen low levels of serotonin and aggressive behaviour

Question 8

ao3: support for serotonin as a hormonal mechanism in aggression

Answer 8

Duke et al
-support for the serotonin deficiency hypothesis as an explanation for aggressive behaviour in human beings
-meta analysis of 175 studies, 6500 participants
-found small inverse relationship between serotonin levels and aggression, anger and hostility
-the magnitude of relationship varied with the methods used to assess serotonin functioning, with year of publication and self reported versus other reported aggression
-only other reported aggression was positively correlated to serotonin functioning
-therfore, relationship between serotonin and aggression is more complex than origninally thought

Question 9

ao3 RLA for hormonal mechanisms in aggression (serotonin)

Answer 9

-if low levels of serotonin = aggression and impulse, drugs that clinically rise serotonin should produce concurrent lowering of aggression
-Mann et al: administered dexfenfluramine to 35 healthy adults (which depletes serotonin in brain). Used questionnaire to assess hostility and aggression levels - rose amongst males, but not females
-demonstrates issue of beta bias - males and females may not be subject to the same physiological factors when explaining aggression

Question 10

ao1: testosterone as a hormonal mechanism in aggression

Answer 10

Testosterone is an androgen - development of masculine features
-females also have it but in lower levels
-increases muscle mass etc.
-men are generally more aggressive than women (10x more) = thoughts testosterone levels are related to aggression
-at age where testosterone is highest, 21-35, increase in male on male aggressive behaviour
-it also influences levels of serotonin in the brain, so can reduce serotonergic activity - low levels of this are implicaed in increased aggressive behaviour
-so it seems to mediate the effects if itger biochemicals too

Question 11

ao1: studies for testosterone linked to aggression

Answer 11

Dabbs: measured testosterone in saliva of 692 adult male prisoners
-higher levels in rapists and violent offenders than in non-violent burglars and thieves

Question 12

ao3 for testosterone in aggression: inconsistent evidence

Answer 12

Albert et al
-other studies find no positive link between testosterone levels and aggression
-may be due to the methods of psychologists, like small samples from prisons, self report measures, or judgements based on severity of crime
-advocates that the relationship between testosterone and aggression remains unclear

Question 13

ao3 for testosterone in aggression: inconsistent evidence (Klinesmith)

Answer 13

Klinesmith et al (2006)
-investigated potential link between presence of a stimulus, like a gun or knife and the increase in aggressive behaviour
-male college students provided a saliva sample and then interacted with a gun or childs toy for 15 mins
-another saliva sample showed the gun increased testosterone and they behaved more aggressively towards other participants compared to those who played with the childs toy

Question 14

ao1: what is ethology

Answer 14

-ethology is the study of animal behaviour in natural settings - suggests main function of aggression is adaptive, and beneficial to surviva

Question 15

ao1: Lorenz and ethology

Answer 15

Lorenz - suggested animals had an innate mechanism for aggression, and that aggressive behaviour acted as a release. It builds up until next aggressive act. The innate releasing mechanism is the specific neural circuits hardwired into the brain which monitor the drive, such as aggression

Question 16

ao1: whats an innate releasing mechanism (1)

Answer 16

is the specific neural circuits hardwired into the brain which monitor the drive, such as aggression

Question 17

ao1: what a fixed action pattern and list main features

Answer 17

FAP - environmental (sign) stimulus triggers IRM. Released a sequence of behaviour. called the FAP. sequence of behaviours that occurs throughout the species. describes a universal behaviour, FAPs are thought to be innate

Lea (1984): 6 main features of FAP
1. sterotyped
2. universal
3. unnaffected by learning
4. ballistic
5. single purpose
6. specific triggers

Question 18

ao1: introduction: ethological explanation for aggression

Answer 18

-ethology is the study of animal behaviour in natural settings - suggests main function of aggression is adaptive, and beneficial to survival

Lorenz - suggested animals had an innate mechanism for aggression, and that aggressive behaviour acted as a release. It builds up until next aggressive act. The innate releasing mechanism is the specific neural circuits hardwired into the brain which monitor the drive, such as aggression

FAP - environmental (sign) stimulus triggers IRM. Released a sequence of behaviour. called the FAP. sequence of behaviours that occurs throughout the species. describes a universal behaviour, FAPs are thought to be innate

Lea (1984): 6 main features of FAP
1. sterotyped
2. universal
3. unnaffected by learning
4. ballistic
5. single purpose
6. specific triggers

Question 19

ao1: example for ethological explanation of aggression

Answer 19

Tinbergen: stickleback fish
-used models crafted to resemble male sticklebacks (with red bellies) and females (with swollen bellies).
-male sticklebacks attacked the model designed to look like a male member of the species
-shows the behaviour is invarient (all males do it). Strong argument for the behaviour being innate

Question 20

ao1: ethology - ritualistic aggression

Answer 20

-ethologists have shown that not all aggressive behaviour involves fighting but may be ritualised in the form of threat displays
-important for contestants because they help individuals to assess their relative strength before deciding to escalate conflict
-male gorillas as an example - chest poundding - intimidate opponent witrhout physical contact

Question 21

ao1: ethology - instinctive inhibitors

Answer 21

-some species have evolved fearsome weapons making them effective hunters
-like wolves, they have instinctive inhibitors which prevent them from using these weapons against members of their own species
-humans do not have this to prevent aggression against conspecifics (same species)

Question 22

ao3: ethology - benefits of ritualized aggression +

Answer 22

non human species - benefits involve it preventing conflict escalating into potentially dangerous physical aggression
-evidence to suggest this advantage is also evident in human cultures
Chagnon; among the Yanomamo people of south america, chest pounding and club fighting contests can settle a conflict short of more extreme violence
Hoebel: among Inuit Eskimos, song duals used to settle grudges and disputes

= even in moderately to high violent cultures, they act to reduce actual aggression, preventing injury or death of the combatant

Question 23

ao3: ethology - fixed action patterns are argued to not be innate (with topping) -

Answer 23

Lehrman - believed Lorenz had under estimated the role of environmental factors in the deveoplment of species-typical behaviour patterns.
- these are largely the result of learning and experience
-nor is the behaviour as fixed as implied by “fixed action pattern”.
-a key point is tht the behaviour is universal to the species
-not the case for humans- some will act aggressively and some will not in certain situations
Nisbett: Found a north-south divide in the united states for homicide rates. More common for white males in southern states than northern. Difference concluded is caused by “culture of honour”, a learned social norm
Therefore, there are subtle variations in species, meeaning patterns of aggressive behviour may not be as fixed as Lorenz believes

Topping - reductionism - reduces aggressive behaviour down into its simplest form - FAP

Question 24

ao3: for ethological explanation - human FAP of aggression is no longer adaptive

Answer 24

Eibl-Eibesfeldt - identified a number of human FAPs e.g. smiling, eyebrow flash
-because our environment changes so rapidly, suggests FAps such as aggression are no longer adaptive in modern times.
- an issue with explaining human aggression this way is that it should confer with an evolutionary advantage
-for exmaple : females do not want an agressive partner - reduces chance of reproductive success abd has not shown aggression to be an adaptive mechanism. the flexibility of human nature has proved to be more effective
Suggests: although nonhumans may respond aggressively to sign stimuli, human behaviour is more varied and less predictable

Question 25

ao3: ethological - killing conspecifics isnt that rare

Answer 25

• problem for this explanation of aggression is that it claims the predator species msust have instinctive inhibitors that prevent them using their natural weapons against members of their own species
  -in some predator species, the killing of their own is more systematic and not so accidental
• e.g. lions kill off all cubs of other males
  these findings pose a challenge for the ethological explanation of aggression as they cast doubt on the claim that much of animal aggression is ritualistic rather than real

Question 26

ao1: evolutionary explanations of human aggression

Answer 26

-would suggest this enabled our ancestors to better survive in a competitive environment
-through natural selection, those that demonstarted aggressive qualities = able to acquire resources and mates effectively to improve survival and reproductive success
-male aggressiveness may be attractive to females = appear strong to protect offspring
sexual competition = jealousy is when an individual fears losing the affections of a mate to another individual
-aggression develops out of need to ensure a partner is faithful
-males are more likely to respond negatively to sexual infidelity and jealousy - they would run the risk of upbringing another males offspring (cuckoldry) if their partner cheated
-this an evolutionary problem as the male would have to raise another mans child, spending less or no time helping reproduce his own genes

Daly and Wilson: males have evolved aggressive tactics to avoid this
- Direct guarding
- Negative inducements (consequences)
- Domestic violence (power)

Dobash and Dobash: Studies of battered women show that women blame jealousy of their boyfriends or husbandds as the cause of violence

key study: Buss
Chagnon: aggression in warfare

Question 27

Ao1: Key study for evolutionary explanations of human aggression

Answer 27

Buss: investigated the nature of jealousy in men and women
-cross cultural questionnaire
-heart rate and GSR measurements
-hypothetical question , “Would you be more jealous if your partner had sex with someone else or if they formed a deep emotional connection with another person?”
-Found men 60% more jealous = sexual relationship
-Women 85% jealous = deep emotional attachment
Womens jealousy = man can leave for another woman, leaving her less resources for her and children
Mens jealousy = uncertainty of paternity of children

Question 28

ao1: discuss aggression in warfare (Chagnon)

Answer 28

-male warriors in traditional societies have mroe sexual partners and children suggesting reproductive benefit of wars as they show aggressiveness and bravery which is attractive to females
-obtains valuable resources

Question 29

ao3: evolutionary explanations of aggression - support for the link between aggression and status

Answer 29

-aggression confuring greater status is supproted by anthropological evidence - many tribal societies bestow increased status and honour men who have committed murder (Daly and Wilson).
Also evident in industrialised societies like the US where most violent gang members often have the highest status among peers (Campbell)
Suggests = aggression not only important way of gaining status among males, but a consequence of threats to that status

Question 30

ao3: evolutionary explanations of aggression: aggressive behaviour may not always be adaptive

Answer 30

-an issue with aggressive behaviour being an effective way to meet challenges of social living is it may result in social rejection (otracism), injury, or death
-violent males might be rejected as mates - might be considered maladaptive than adaptive

Duntley and Buss: benefits of aggression must only have outweighed the costs on average relative to other strategies in the evolutionary past

-if this is case, natural selection would favour evolution of aggression , despite its apparent maladaptiveness

Question 31

ao3: evolutionary explanations of aggression: gender bias in evolutionary explanations of aggression

AND TOPPING: Socialisation

Answer 31

-gender bias - physical aggression in warfare do not adequately reflect the behaviour of women
Adams: claimed a woman warrior is unheard of in most societies theyd have less to gain and more to lose (reproductive capacity) this is fundamental to womens exclusion, as women do not increase their fitness as much as men do
-our understanding of physical displays typically found in warfare is therefore limited to behaviour of males rather than females

HOWEVER, gender differences - better explained by socialisation
Prinz: differences in agg behav of male/female may be product of different socialisation experiences
-Smetana found parents more likely to physically punish boys, and explain to girls why their actions are wrong

Question 32

ao3: evolutionary explanations of aggression: limitations of the evolutionary explanation

AND TOPPING

Answer 32

-based on mating success, sexual jealousy or the acquisition of status in warfare fail to explain levels of cruelty found in human conflicts, yet are not evident in non-human species
-dont explain wide scale slaughter of whole groups - evident in the Rwandan genocide 1994.
-dont tell us why humans torture or mutilate their opponents when theyve already been defeated and no longer pose a threat

TOP: anthropological evidence suggests this may be more of a consequence of de-individuation effects than of evolutionary adaptations

Question 33

ao1: social psychological explanations of aggression: 1. frustration aggression hypothesis

Answer 33

this theory based on work of Dollard
-aggression is consequence for feelings of frustration
-this is when you are trying to achieve something and there are barriers preventing you from reaching your aim
-unpleasant feeling which needs to be relieved
-aggression allows for relief to happen which is cathartic to the individual, a form of emotional release when engaging in aggressive behaviour

Factors affecting likelihood of aggression occuring:
1. Proximity to goal - closer = more likely for agg to occur
2. Whether the aggression will remove the barrier causing the frustration
3. Whether or not it is justified frustration. Pastore - bus stop not picking up passengers. Found levels of agg expressed in justified settings were lower than in unjustified settings

The hypothesis recofnises might not always be expressed directly against the source of frustration because its inappropriate or risk punishment, so it needs to be deflected onto an alternative. to experience catharsis, a scapegoat needs to be found

Question 34

ao3: social psychological explanations of aggression: 1. frustration aggression hypothesis: research support key study

TOPPING: METHODOLOGICAL WEAKNESS

Answer 34

Green (1968)
male uni students given puzzle to complete
level of frustration was experimentally manipulated in one of three ways
1. puzzle being impossible to solve
2. ran out of time as another student (confederate) kept interfering
3. confederate insulted the participant as they failed to solve the puzzle
Next part involved giving electric shocks to confederate when they made a mistake on another task
- found insulted participants gave strongest shocks, impossible task participants gave the lowest. all 3 groups selected more intense shocks than a control group

TOP: Low ecological validity - not many people do puzzles - not app to real life
Only males - gender bias - cant generalise