Aggression

Question 1

Definition of aggression

Answer 1

Behavior that leads to self assertion, angry and destructive behavior causing injury. An act carried out with the intention of harming another person

Question 2

Define proactive aggression

Answer 2

-Cold blooded
-A planned method of getting what you want

Question 3

Define reactive aggression

Answer 3

-Hot blooded
-Angry and impulsive, accompanied by physiological arousal

Question 4

Outline the role of the amygdala in aggression

Answer 4

-Most important structure in terms of aggression
-The amygdala is a key structure for humans and non-humans in terms of assessing and responding to threats in an environment
-The reactivity of the amygdala in humans has proven to be an important predictor of aggressive behavior
-Additionally, if the limbic system malfunctions/becomes damaged, this can raise levels of testosterone, making aggressive behavior more likely

Question 5

AO1
Evidence for limbic system

Answer 5

-Ultimate game, lab experiment
-Gospic et al
-2 players are asked to divide a given amount of money, the confederate must decide how this money should be divided, while the responder (ppt) may reject or accept the offer
-If the responder accepts the offer, both players receive money
-If the responder rejects, neither of them gets anything
-At the same time, the responders (ppt) had an FMRI scan
-When the responder rejected the unfair offers (an aggressive reaction to social provocation) there was fast and heightened response in the amygdala recorded
-Ppts were given benzodiazepine (drug which reduces arousal in the CNS) before the game
-It halved the number of rejections to ‘unfair offers’ (reduced aggression) and decreased the activity in the amygdala
-THEREFORE SHOWING AN ASSOCIATION BETWEEN REACTIVE AGGRESSION AND AMYGDALA ACTIVITY

Question 6

Outline the role of serotonin in aggression

Answer 6

-Serotonin has an inhibitory effect on the brain (slows down and dampens neurological functioning)
-Normal levels of serotonin the orbitofrontal cortex are linked to reduced firing of neurons and this is associated with a greater degree of self control
-Decreased levels of serotonin may disturb the mechanisms in OFC
-Reducing self control and leading to an increase in impulsive behavior such as aggression

Question 7

AO1
Evidence for serotonin affecting aggression

Answer 7

-Virkkunen et al (1994)
-Compared levels of serotonin breakdown product (metabolite called 5-HIAA) in the cerebrospinal fluid of violent impulsive and violent non-impulsive offenders
-The levels were significantly lower in the impulsive offenders (also suffered sleep irregularities)
-Serotonin regulates sleep patterns
-Disturbance of this pattern strongly implies some disruption of serotonin functioning
-Further supporting the role of serotonin in reactive aggression

Question 8

Explain the effect of serotonin on aggression

Answer 8

Serotonin has widespread inhibitory effects on the brain; it slows down and dampens neuronal activity.

MAKES AGGRESSION LESS LIKELY

Question 9

Outline the role of testosterone in aggression

Answer 9

-Male sex hormone and androgen responsible for the development of masculine features
-It also has a role in regulating social behaviours via its influence on certain areas in the brain implicated in aggression
-There is lots of documented evidence of testosterone being increased in various species which has resulted in increased aggression. Lower test lowers aggressive behaviours

Question 10

AO1
Testosterone on aggression study

Answer 10

-Dolan et al 2012
-Studies of prison populations
-Found a positive correlation between testosterone levels and aggressive behaviours
-Sample of 60 males (high security prison)
-These males suffered from personality disorders and had history of impulsive violent behaviour

Question 11

AO3
Outline one strength of the hormonal explanations of aggression
(Supporting research, Berman et al)

Answer 11

One strength of the neural explanations of aggression is that there is supporting research from Berman.
Berman carried out an experiment where he gave ppt’s either a placebo or a drug which increases serotonin. Ppt’s took part in a game whereby they could give electric shocks (due to provocation). Berman found that those who took the drug gave loss shocks than those who took the placebo, indicating that higher levels of serotonin result in lower levels of aggression.
This research clearly demonstrates that a lack of serotonin may directly be linked to increased levels of aggression as increasing serotonin levels can actually reduce aggressive responses. This is in line with what the theory predicts, thus strengthening our acceptance of the neural explanations of aggression.

HOWEVER, a problem is that this research is correlational and therefore we cannot ascertain causality e.g. Low levels—> Increase aggression or vice versa, therefore it is a limited explanation of aggressive behaviour

Question 12

AO3
Outline one weakness of the hormonal explanations of aggression
(Dual hormone hypothesis)

Answer 12

One weakness of the hormonal explanations of aggression is that the role of testosterone may be overamplified.
For example, Carre and Mehta suggested testosterone cannot work alone in determining aggression, but rather has an antagonistic relationship with the stress hormone cortisol, where increased levels of aggression are associated with increased testosterone levels but only when cortisol is low. Therefore, this implies that different hormones have different predictive values for aggression and are part of a system when developing aggressive behaviour.
Therefore, this weakness acceptance of the hormonal explanation as it lacks detail when referring to other hormones interacting with testosterone to produce aggressive behaviours

Question 13

AO3
Outline one weakness of the neural explanations of aggression
(Reductionist)

Answer 13

One weakness of the neural explanations of aggression is that it is reductionist as it ignores other brain structures when explaining aggression.
For example, recent studies suggest that the amygdala appears to function alongside the OFC (not part of the limbic system). Cocarro et al found that patients with psychiatric disorders (which often displayed aggression), activity in the OFC was reduced.
Aggressive behaviour may actually better be explained as a connection between both the amygdala’s activity and reduced activity within the OFC, which implies the explanation is limited for only focusing on the role of the amygdala in aggression.
Overall, this is a weakness of the neural explanations because aggression may be far more complex than the explanation suggests

Question 14

AO3
Outline one weakness of the neural explanations of aggression
(Cause and effect)

Answer 14

Much of the research onto neural/hormonal explanations of aggression is correlational. A strength of this is the avoidance of ethical issues from experimental manipulation e.g. altering a ppts hormonal levels would be extremely unethical
However the main weakness of much of this research means that the findings are still largely inconclusive. We can only see a link between two variables but cant tell what variable caused what result. E.g. increased amygdala activity and aggressive behaviour, but we are unclear on which variable causes the other

Question 15

Concordance rates for genetic explanations of aggression

Answer 15

Cocarro et al (1997)
Concordance rates (physical assault) = 50% for Mz and 19% for Dz twins

Question 16

AO3
Problems with twin studies

Answer 16

-Twin share genes but also share environments meaning it is very difficult to ‘detangle’ genetic and environmental influences

-If aggression is purely determined by our genetics then we would expect the concordance rates for Mz twins to be much higher/nearer to 100%

Question 17

Explain the use of adoption studies in aggression

Answer 17

-Detangle gene/environment interaction
-This is an important method because if we find greater similarity between children and their biological parents then the tole of genetics can be assumed to be a significant factor in determining aggressive behaviour
-If people are more like adoptive parents —> Environment more influential

Question 18

AO1
Denmark adoption study

Answer 18

-Over 14000 adoptions
-Found that significant numbers of boys with criminal convictions also had fathers (biological) with criminal convictions of violence
-Provides support for genetic link

Question 19

AO1
Explain the role of the MAOA gene in aggressive behaviour

Answer 19

-Mono amine oxidase A
-Low activity of this gene affects production of the MAOA enzymes
-Leads to MAOA enzyme activity is associated with various forms of aggressive behaviours
-‘Warrior gene’
-Gene is possessed by 56% of Maori men compared with 34% of Caucasian men who possess the gene
-Low activity variant is closely associated with aggressive behaviour

Question 20

AO1
Research for MAOA gene
(Brunner et al)

Answer 20

-Found 28 men from a large Dutch family who were repeatedly involved in impulsively aggressive violent criminal behaviour such as rape, attempted murder and physical assault.
-These men had abnormally low levels of the enzyme MAOA as well as the faulty MAOA gene

Question 21

AO1
Research support for MAOA gene
(Stuart et al)

Answer 21

-Studied 97 men from a treatment program for domestic abusers, who had inflicted a form of aggression called intimate partner violence (IPV)

-Men with low activity MAOA gene were found to be the most violent perpetrators of IPV, engaged in the greatest psychological and physical aggression and inflicted the worst injuries on their partners

Question 22

AO1
Gene environment interaction
(Frazzetto et al)

Answer 22

-Genes don’t function in isolation
-Low activity of MAOA gene is only related to adult aggression when combined with traumatic events

-Frazzetto found an association between high levels of aggression and low activity of MAOA gene in adult males. This was only the case for those that experienced significant trauma before the age of 15.
-Those that didn’t experience abuse but had low activity f MAOA gene did not exhibit particularly high aggression in adult life

Question 23

AO3
Outline one weakness of the genetic explanations of aggression
(Separating genes from environment)

Answer 23

One weakness of the genetic explanations of aggression is the problem of separating genetic and environmental influences
For example, although the evidence that comes from twin studies does support the idea of genetic link for aggression, the issue is that twins still do share the same environment/rearing and it is not possible to fully separate the two factors
Furthermore, if the trait was purely genetic, concordance rates would be closer to 100% for this shared trait. Therefore it seems that this explanation is reductionist which implies there must be other influences e.g. environmental factors when explaining aggression. Perhaps aggression could better be explained by by gene X environment interactions. For example, Frazetto found that low activity MAOA gene and childhood trauma made aggressive behaviour more likely.
This research therefore weakness the sole genetic explanation but provides further support for the diathesis stress model as an explanation for aggressive behaviour

Question 24

AO3
Outline one weakness of the genetic explanations for aggression
(Measuring aggression)

Answer 24

One weakness of the genetic explanation of aggression is that some of the supporting research lacks validity.
For example, meta-analysis data from both twin and adoption studies have come from self-report methods, parent/teacher reports (which are both secondary data sources) and some direct observations.
This is problematic because the methods used to study aggression are not reliable. Not only this, self report methods have the issue of social desirability bias as people may be dishonest when speaking about their involvement in aggressive behaviour as it maybe socially sensitive.
This means the overall findings that come from such studies may not be entirely accurate or valid, thus weaking acceptance of the biological explanation of aggression

Question 25

AO3
Outline one strength of the genetic explanation of aggression + counter
(Supporting research)

Answer 25

One strength of the genetic explanations of aggression is that there is research support for the role of the low activity MAOA gene from animal research.
For example, Cases et al found that when the MAOA gene in the X chromosome of mice was disabled, make mice became highly aggressive. This is what coincides with the genetic explanation of aggression, thus strengthening acceptance of the theory.
However, it is difficult to extrapolate the finings from animals and then apply them to humans. Humans are much more physiologically and cognitively developed than animals and we have a far more developed Pre-frontal cortex than animals. Therefore, we should accept research from animals with caution as they may not be fully applicable to understanding human aggression on a deeper level

Question 26

AO3
Outline one weakness of the genetic explanations of aggression
(Polygenic)

Answer 26

The role of genetic factors in aggression is a reductionist argument as it appears there may be more than just once gene linked to aggressive behaviour.
For example, Stuart et al studied males who were involved in IPV and found that aggression was not only linked to MAOA gene activity but also the 5HHT serotonin transporter gene.
This research undermines the original explanation which suggests a low activity MAOA gene is solely responsible for aggressive behaviour, as it appears aggression is far more complex and must be explained through multiple genetic factors. Therefore this weakens acceptance of the genetic explanations of aggression as it undermines the role of other genes in aggression.

Question 27

What role does the hippocampus play in aggression?

Answer 27

It sends information stored in our memory to the amygdala.

Question 28

What role does the frontal cortex play in aggression?

If the frontal cortex is damaged, then…

Answer 28

It inhibits neurons in the amygdala

-The amygdala keeps sending impulses to the hypothalamus.
-The brain continues to produce aggressive behaviour.

Question 29

The role of serotonin in aggression

Answer 29

-Serotonin inhibits neurons in the amygdala
-Serotonin inhibits neurons in the amygdala
-Serotonin reduces aggressive behaviour

Question 30

Sumer et al
Support for role of the amygdala in aggression

Answer 30

Sumer et al conducted a case study of a 14-year-old girl who had begun to display excessive aggression. The researchers carried out a/an MRI scan which showed a tumour on the girl’s amygdala, causing it to be more active and send more nerve impulses to the hypothalamus. This increased her aggression.

Question 31

AO1 research
Mpakopoulou’s study into the role of the amygdala in aggression

Answer 31

-Before the amygdalotomy, the patients had excessive activity in their amygdala
-Before the surgery, the patients were displaying high levels of aggression
-The amygdalotomies reduced aggression in the patients by 33-100%

Question 32

AO3
Weakness of research into the role of the amygdala in aggression

Answer 32

While some studies have found that a damaged amygdala is associated with a decrease in aggression, others have reported an increase in aggression.
This suggests that the role of the amygdala might differ depending on the sub-region of the amygdala and the role of the amygdala may be more complicated than first thought.

Question 33

AO1
Outline the ethological explanations of aggression

Answer 33

-Ethology refers to the study of an animal in its natural setting
-Suggests aggression is an instinct, it occurs in all members of species WITHOUT NEED FOR LEARNING
-Aggression is required for survival
-Aggression is adaptive meaning it aid survival in the animal kingdom
-Any species that is aggressive can reproduce and pass on genes to their offspring
-Aggression allows a species to survive because a ‘defeated’ species is rarely killed but rather is forces to establish territory elsewhere
-This means that members of a species spread out over a wider area and have to discover resources in a different place which reduces competition pressure and possibility of starvation

Function 2:
-Aggression helps us establish dominance hierarchies, thereby giving access to territory, resources and mates
-Aggression would then be naturally selected

Question 34

Explain ritualistic aggression

Answer 34

-Lorenz’s early observation of fights between animals of the same species showed very little physical damage was done

-Most aggressive encounters consisted mainly of a period of ritualistic signals: Threat displays and appeasement gestures

-Such ritualistic behaviours are adaptive because if every aggressive encounter ended with death, it could threaten the existence of the species

-Threat displays are intended to make the opponent back down and are the last step before the animal either fights, submits or leaves

Question 35

AO1
Outline the Innate releasing mechanism (IRM)

Answer 35

-Network of neurons in the brain which responds to threats in the environment in the form of aggression/aggressive behaviour

-An environmental stimulus (e.g. facial expression) triggers the IRM which then ‘releases’ a specific sequence of behaviours

-This behavioural sequence is called a fixed action pattern (FAP). FAP has 6 main stages:
1) Stereotyped - Relatively unchanged sequence of behaviours
2) Universal - The same behaviours found in every individual
3) Unaffected by learning - The same for every individual regardless of experience
4) Ballistic - Once the behaviour is triggered it follows an inevitable course
5) Single purpose - behaviours occur in a specific situation and no other
6) Responsive - A response to a specific sign stimulus from a member of the same species

Question 36

AO1
Research Into fixed action patterns (FAP) and Innate releasing mechanism (IRM)
(Tinbergen et al)

Answer 36

-Sticklebacks are highly territorial and aggressive (develop a red spot on their underbellies due to mating season itself)
-If another male enters their territory, FAP is shown. The ‘sign’ stimulus that triggers the innate releasing mechanism is the sight of the red spot

-Tinbergen presented the sticklebacks with a series of wooden models of different shapes.
-Regardless of shape, if the wooden model had a red spot then the stickleback would aggressively display behaviours and even attack it, but if there was no red spot. there was no aggression
-Tinbergen also found that these aggressive FAP’s were unchanging from one encounter to another. Once triggered, the FAP always ran its course to completion

Question 37

AO3
Outline one weakness of the Ethological explanations of aggression
(Generalisability)

Answer 37

One weakness of the Ethological explanations of aggression is that it is not entirely valid to make generalisations from animal to human aggression without evidence.
For example, Lorenz and Tinbergen assumed that the behaviour thy observed in birds and fish must also be the same for humans. Therefore, aggression must be instinctive and innate in humans too.
This suggests we should be extremely cautious about making generalisations, especially to a behaviour (such as warfare) which is extremely complex and the outcome of many interacting influences, including things like; learning personality factors and power. Humans are more emotionally complex than animals, which isn’t accounted for these explanations. Therefore this weakens acceptance overall because it may not be appropriate to apply animal aggression to human aggression.

Question 38

AO3
Outline one weakness of the Ethological explanations of aggression
(MAP’s instead of FAP’s)

Answer 38

One weakness of the ethological explanations is that behaviours may have more environmental influence than was first suggested.
This is confirmed by the fact ethologists increasingly accept that FAP’s are flexible and the term isn’t used as it once was, being gradually replaced by modal action patterns (MAP’s). It has been found that the duration of each aggressive behaviour varies from one individual to another. Research suggests there are small differences between the members of the same species in relation to aggression suggesting they are not fixed as Lorenz suggested.
The flexibility of FAP’s may imply that aggressive behaviour can be learned or area at least affected by environmental learning, thus weakening acceptance of the ethological explanations as they dont account for this learning aspect

Question 39

AO3
Outline one weakness of the Ethological explanations of aggression
(Aggression is not always self limiting)

Answer 39

One weakness of the ethological explanations of aggression is that aggression is not always self limiting like the theory always suggests.
For example, aggression does lead to harmful behaviour within a species. Male chimpanzees in one group set about strategically killing all members of another group of chimpanzees, doing so in a co-ordinated and pre-meditated fashion. Violence continued despite signs of appeasement and defencelessness. This is strong evidence to go against the ethological explanations which suggest aggression is adaptive as a mechanism to promote survival, therefore weakening our acceptance of the ethological explanations when explaining aggression

Question 40

AO3
Outline one strength of the Ethological explanations of aggression
(Supporting research)

Answer 40

There is supporting research for the innate basis of aggression in humans and non-human animals. For example, the existence of the ‘innate releasing mechanism’ linked to aggression and threat detection in humans/animals is the limbic system (amygdala reacts to threatening stimuli and predicts aggressive behaviour). This supports a central prediction of the ethological explanations: aggression is genetic and physiological.
Such research supports the genetic and physiological basis of aggression that ethologists predicts, thus supporting the notion that aggression is biologically predetermined, thus strengthening acceptance overall