Aggression- Paper 3

Neural Mechanisms of Aggression: The limbic system

The limbic System exists only in mammals. Its regions mediate emotional stress, and memory processes. It is made up of several structures:

1. Amygdala- plays a role in aggression, eating, drinking and sexual behaviours

2. Hippocampus- plays an important role in memory, learning and emotion 

3. Hypothalamus- regulates processes in the body through its connection to the central and autonomic nervous systems and the endocrine system

Neural Mechanisms of Aggression: The Amygdala

The Amygdala is responsible for emotion and aggression. It evaluates sensory input and decides appropriate responses. The more reactive it is to environmental threats, the more likely it is that aggression will be shown. However, if damaged, aggressive behaviour also results. 

Case Study: Pardini et al (2014) Male brain scans and Amygdala Anomalies 

• A longitudinal study of 56 male participants with varying histories of violence.  Had MRI brain scan at 26 years old. 

• Findings showed a negative correlation between the volume of their amygdala and higher levels of violence. 

• Therefore, showing reduced amygdala volume can predict severe and persistent aggression.

• This shows that the amygdala plays a role in interpreting sensory information and that low volume amygdala makes violence more likely thus supporting the importance of the limbic system (amygdala specifically) in causing aggression.

Case Study: Phineas Gage 

• Phineas had damage to his amygdala after a pole went through his eye, this lead to excessive aggression and irritability for the rest of his life 

Neural Mechanisms of Aggression: Serotonin

• Serotonin, in normal levels, seems to have a calming inhibitory effect on neural firing in the prefrontal cortex, so therefore associated with greater behavioural self-control. 

• Decreased Serotonin disrupts this mechanism, which results in individuals being less able to resist the impulse to be aggressive, and reduces self control.

• However, evidence into the effects of serotonin have been mixed though, with some research indicating that high/elevated levels of serotonin also increase aggressiveness.

Case Study: Bermans et al’s (2009) research into the effects of serotonin on aggression 

• Participants took part in a laboratory-based game, giving and receiving electric shocks in response to provocation.  

• Participants who took Paroxetine (enhances serotonin) consistently gave fewer and less intense shocks than a placebo group.  

• These findings showed evidence of a causal link between serotonin and aggression. 

• It is still important to remember that the exact role serotonin plays in aggression is unclear.  Many studies have shown that high levels of serotonin can still lead to aggressive behaviours too.

AO3 Evaluation: Neural Mechanism of Aggression

• Research support

  1. Pardini et al (2014)

  2. Phineas Gage 

  3. Bermans et al (2009)

• Biologically reductionist- A neural mechanism explanation of aggression is considered biologically reductionist because it attempts to explain a complex behaviour like aggression by solely focusing on the activity of specific brain regions and neurotransmitters, essentially reducing the multifaceted nature of aggression to a simple biological process, often overlooking important environmental and social factors that contribute to aggressive behaviour e.g. stress, social norms, and life experiences can significantly influence aggression 

• Nature/Nurture- The neural mechanism explanation of aggression is considered "nature" because it attributes the propensity for aggressive behaviour to biological factors within the brain, specifically the activity of certain neural structures like the amygdala, which are largely predetermined by genetics and not significantly influenced by environmental factors in the short term; essentially suggesting that the capacity for aggression is an innate characteristic present in all individuals to some degree. 

• Other brain structures- One limitation of the limbic explanation is more recent research showing that non-limbic brain structures are also involved in aggression. Limbic structures (e.g. Amygdala) function together with the orbitofrontal cortex (OFC), which is not part of the limbic system. The OFC is involved in impulse regulation and inhibition of aggressive behaviour. According to Emil Coccaro et al (2007), OFC activity is reduced in those psychiatric disorders that feature aggression. This reduced activity disrupts the OFC’s impulse-control function, which in turn causes aggressive behaviour. This shows that the neural regulation of aggression is more complex than theories focusing on the Amygdala suggest. 

Hormonal Mechanisms of Aggression: Testosterone

• Hormones are chemical messengers that are released by a cell or gland in one part of the body that affects and sends messages to target cells in other parts of the body. 

• Testosterone is a hormone responsible for the development of masculine features. It helps regulate social behaviour via influence on areas of the brain (and body) involved in aggression. Males are more aggressive towards other males at 20+ years old when testosterone levels peak. 

• Testosterone studies are mainly carried out on animals (due to ethics)

Case Study: Simpsons (2001) hormone subtraction and replacement studies

• Measured the normal level of aggression in mice

• Castrated the mice

• Castration = decrease in aggression seen in mouse behaviour

• Replacement of testosterone through hormone therapy (HRT) = increase of aggression; restored almost to its original pre-castration level

Case Study: Klinesmith et al (2006) Behaviour Regulating Hormone Hypothesis

• Aim- to investigate the change in testosterone levels as a result of aggressive interactions

• Method- Male students (aged 18-22). Saliva sample was taken. Task was to take an object apart and then reassemble the object, test it, and write instructions. In Group 1 the object was a pellet gun. In Group 2, the object was a mousetrap game (toy). A saliva sample was then taken again 

• Findings - 100 x more testosterone in the saliva of Group 1 in the 2nd saliva sample (after interaction with pellet gun)

• Conclusion - Environmental stimuli (e.g. guns) may increase aggressive cognitions, and as a result, increase the levels of testosterone secreted into the body.

Hormonal Mechanisms of Aggression: Progesterone

There is some evidence that progesterone plays an important role in aggression in women. Levels of progesterone vary during the ovulation cycle and lowest during and just after menstruation. Ziomkiewicz et al (2012) found a negative correlation between progesterone levels and self reported aggression. This suggests that low levels of progesterone are linked to increased aggression in women.

AO3 Evaluation: Hormonal Mechanisms of Aggression

• Research Support 

  1. Simpsons (2011)

  2. Klinesmith et al (2006) 

  3. Ziomkiewicz et al (2012)

• Biologically reductionist- The hormonal mechanism of aggression is considered biologically reductionist because it attempts to explain a complex behaviour like aggression by simply attributing it to fluctuations in hormone levels, essentially reducing a multifaceted issue down to a single biological factor, ignoring the significant influence of environmental and psychological factors that contribute to aggressive behaviour  

• Nature/Nurture- Nature. Research shows a strong correlation between high testosterone levels, a naturally occurring hormone, and increased aggressive behaviour in humans and animals, suggesting a biological predisposition towards aggression influenced by hormonal fluctuations within the body; essentially, the potential for aggression is partly built-in due to the presence of these hormones.  

• Animal Research- Marco Giammanco et al’s (2005) review of studies confirms the role of testosterone. For example, in male rhesus macaque monkeys there is an increase in both testosterone levels and aggressive behaviour during the mating season. In rats, castration of males reduces testerone and also mouse-killing behaviour. Injecting female rats with testosterone increases mouse-killing. These findings show the role of testosterone in a range of animal species 

• Dual hormone hypothesis- One limitation is mixed evidence of the link between testosterone and aggression in humans. Carre and Mehta (2011) developed a dual hormone hypothesis to explain why. They claim that high levels of testosterone lead to aggressive behaviour but only when levels of cortisol are low. When cortisol is high, testosterone influence on aggression is blocked. The hormone cortisol plays a central role in the body’s response to chronic stress. Therefore, the combined activity of testosterone and cortisol may be a better predictor of aggression than either hormone alone. 

Media Influences on Aggression

1. Excessive TV viewing

2. Violent film content

3. Tv/film effects

4. Computer games

Excessive TV viewing

• Robertson et al (2013), measured the TV viewing hours of over 1000 individuals at regular intervals up to the ages of 26. The researchers found that time spent watching TV in childhood and adolescence was a reliable predictor of aggressive behaviour in early adulthood (defined as convictions for aggressive and violent crimes)

• According to the researchers, excessive time spent watching TV is associated with reduced social interaction and proper educational achievement. No real experiences of conflict resolution and social norms related to how conflict can be resolved without aggression. This means the link between excessive viewing and aggression may be indirect.

Violent Fim Content

• Viewing violent content is perhaps the most significant influence on aggressive behaviour via social learning theory 

• Through operant conditioning and vicarious reinforcement 

• Bandura et al (1963) followed up their earlier research by looking at the effects of aggression viewed on a screen. They replicated their earlier study, except that the children watched a film of the Bobo doll being beaten by an adult model. The outcome was similar, with children imitating the aggressive behaviour of the model (and also of a cartoon version). The social learning processes identified by Banduara operate through media as well as face-to-face.

TV/Film Effects

Other research has found that negative effects of TV/film violence are not as strong as often assumed. Haejung Paik and George Comstock (1994) carried out a meta analysis of about 200 studies. They found a significant positive correlation between viewing TV/film violence and antisocial behaviour. However, they estimated that Tv and film violence probably only accounted for between 1% and 10% of the variance in children’s aggressive behaviour. This implies a relatively minor role for TV and film compared with other sources of aggression.

Computer games

• In Gaming, the player is more active than the passive TV viewers. Also, in gaming the player is directly rewarding (operant conditioning) whereas TV viewing rewards are indirect 

• Advancement of gaming technology: Increase of violence and brutality, use of more realistic graphics and sounds, first person shooter, use of VR and reality vests (tactile stimulation, sensory experience), skinning

• Key case study- Matthews et al (2006)

Methods of Studying the effects of computer gaming

• Can be studied in laboratory conditions often using blasts of white noise to indicate aggression 

• Experimental studies can demonstrate cause and effect (lab studies)

• Correlational studies can investigate real life variables.

• Longitudinal studies can look at long term effects (can be correlational)

• Meta-analysesbring together a variety of studies to give a judgement of size of the effect of violent media on aggression.

AO3 Evaluation: Media Influences on Aggression

• Matthews et al (2006)- Random allocation of 44 adolescent participants to either a violent video game (Medal of Honor) or a non-violent video game (The need for speed). The video games were played for 20 minutes. fMRI (functional magnetic response imaging) scans took place immediately after playing to see an immediate measurement of brain function after playing these games. They found that violent conditions increased activity in the amygdala (increased emotions) and decreased activity in the prefrontal cortex (inhibitions, self control and concentration)

• Bandura’s Second Bobo Doll Study (1963)- Bandura showed 72 children an adult male model being aggressive to a Bobo Doll on a TV screen. The children shown this aggression still imitated the aggressive behaviour from the screen (including the novel aggressive language and aggressive behaviours) despite having not seen it in person. Screen violence is still learnt/imitated through Social Learning Theory. 

Explanations of Media Influences on Aggression

1. Desensitisation

2. Disinhibition

3. Cognitive Priming

Desensitisation (Biological Effect)

• Normally when we witness violent actions we experience physiological arousal associated with the sympathetic nervous system (e.g. increased heart rate, BP, sweatiness, adrenaline).  

• But when children in particular repeatedly view aggression on TV or play violent computer games, they build up a physical tolerance to its effects, resulting in a reduction of anxiety and arousal on repeated viewing/playing (reduced ‘buzz’ from adrenaline), so more violence or aggression is sought to feel the level of excitement desired.

• Example: Horror films which seemed scary as a child might seem tame as an adult due to a physical tolerance. A reduction in psychological arousal (heart rate) when exposed to real violence can occur after repeated exposure to media violence. Desensitised individuals are less likely to notice violence in real life, less empathy is felt for victims, and their injuries are minimised or dismissed. (Funk, 2004)

Disinhibition (Social Effect)

• Example: exposure to violent media could explain why a child would fight with their friends in the playground after watching violent TV at home beforehand. 

• Most people generally hold the view that violence and aggression are antisocial and harmful. Consequently there are powerful social inhibitions against using aggression to resolve conflicts. This is learned through Social Learning Theory. 

• However, if large amounts of violence or other antisocial behaviour is shown in the media then it may be viewed as acceptable 

• Disinhibition explains that these usual restraints are loosened after exposure to violent media.

• Aggressive behaviour is often made to appear normative and justified in violent media and increases the likelihood of an individual being aggressive as a result, especially when the effects of violence on victims are minimised and the aggression appears vindicated

• It is not unusual for video games to reward violence and to ignore consequences of that violence to the victims. This creates new social norms in the viewer.

Cognitive Priming (Cognitive Effect)

• Example: After playing a violent video games children may be more likely to get into immediate fights with their siblings 

• Repeated viewing of aggressive media (especially game playing) can provide us with a ‘script’ (schema) about how violent situations may play out.

• After viewing violent film, the viewer is ‘primed’ to respond aggressively because the memory network involving aggression is activated 

• This process is mostly automatic and unconscious – it directs our behaviour without us being aware of it.

• The schema script is triggered when we encounter cues in a situation we perceive as aggressive.

AO3 Evaluation: Explanations of Media Influences

• Support of Desensitisation- Krahe (2011) showed participants violent (and non-violent) film clips, while measuring physiological arousal using skin conductance tests. Ppts who were habitual viewers of violent media showed lower levels of arousal when they watched the violent clips.  They also reported higher levels of pleasant arousal and lower levels of anxious arousal. Lower arousal in habitual violent media users reflects desensitisation to the effects of violence, and a greater willingness to be aggressive.

• Support of Disinhibition- Berkowitz & Alioto (1973) found that participants who saw a film depicting aggression as vengeance gave more (fake) electric shocks of longer duration to a confederate. This suggests that media violence may disinhibit aggressive behaviour when it is presented as justified (therefore socially acceptable).

• Support of Cognitive Priming- Bushman (2002) Karate Kid Study. Students viewed 15 minutes of aggression from the film Karate Kid 3.  A control group viewed an equally arousing non-violent film (Gorillas in the Mist). Each participant completed a 25 minute trial reaction time task against an imaginary opponent.  Students who won could ‘punish’ their opponent by subjecting them to white noise and could select the punishment level (60-105 decibels).   Participants who watched the aggressive film clip delivered longer and higher intensity punishments than those in the non-violent condition. This supports Cognitive Priming Theory.

• Deterministic- These theories are hard determinist - they state after viewing or gaming aggressive media we WILL become aggressive. Aggressive gaming is commonplace in today's society, however the rates of real aggression remain low.  It is reasonable to believe that people are using their freewill to choose how to behave after watching/gaming, and only those people with underlying issues continue on to violent acts. An interactionist approach between determinism and freewill may provide a more valid theory of media influences on aggression

Genetic factors of Aggression

This involves:

• Studying twins

• Studying Adopted children

• Looking into the Monoamine Oxidase (MAOA) A gene

Twin Studies

• Monozygotic twins= 100% identical genes

• Dizygotic twins= sibling similarity only 

• Concordance rate is the degree of similarity in a pair of twins, and it can be measured for aggressive and antisocial behaviour 

Berkowitz, 1993:

• 87% for MZ twin sets (100% identical DNA)

• 72% for DZ twin sets (non-identical DNA)

Adopted children studies

Similar genetic makeup to biological parents, but raised in a different environment. If aggression is primarily genetically determined, the adopted child will show more similar levels of aggression to their biological parents than their adopted parents. Research shows genetic factors account for about 41% of variance in aggressive behaviour.

Monoamine Oxidase A gene (MAOA)

• Regulates the enzyme Monoamine Oxidase A

• The MAOA enzyme breaks down any neurotransmitters, such as serotonin and adrenaline, which are left at the synapses after an emotion has been relayed.  These neurotransmitters are associated with mood control.

• A build-up of excess neurotransmitters left at the synapse can cause people to respond to stress aggressively (due to an imbalance of chemical messages now in the brain). 

• Normal MAOA gene function regulates the MAOA enzyme to successfully remove excess amounts of these neurotransmitters and reduces aggression.

• People show aggression due to a low-function MAOA gene variant that is unable to produce enough of the necessary MAOA enzyme (MAOA-L)to remove the excesses.

• A faulty MAOA gene (with epigenetic marks) is inherited from parents, and may be triggered into a low function state via diathesis stress of a trauma.  The MAOA-L gene is particularly sensitive to abuse in childhood.

AO3 Evaluation: Genetic factors of Aggression

• Research support- Caspi et al (2002) Longitudinal MAOA New Zealand Study. 1037 Participants. All children- 442 boys & 595 girls in New Zealand. Longitudinal study (26 years: birth to adulthood). Researchers recorded genetic makeup (MAOA-recorded as high or low activity). They noted upbringing recorded any cases of abuse or maltreatment as children. Anti-social behaviour measured using 4 criteria: Diagnosis of conduct disorder during adolescence; conviction for a violent crime; tendency towards violent behaviour and signs of an antisocial personality. They found that the low MAOA gene variant had no effect on its own - only in circumstances of abuse as children; however, abused men carrying genotypes were 3x more likely to commit violent crime. Concluded that  MAOA makes men more likely to be violent, but only if maltreated as children. Less noticeable effect in girls. (This is since it is only found on the X chromosome.  Girls have two X chromosomes and it is suggested that the version of the gene found in one of their X chromosomes could cancel out the effects of the other.)

• Research Support- Brunner (1993) MAOA-L linked with extreme violence in Dutch family. Studied 28 male family members repeatedly involved in impulsive violent criminal behaviours (e.g. rape, attempted murder, assault). These men all had abnormally low levels of the MAOA enzyme in their brains, and had the MAOA-L variant. This supports the theory of genetic factors causing aggression, as this study demonstrates how excess neurotransmitters seem to predispose men to violence when under stress. 

• Problems with twin studies- a limitation of the genetic explanation is that twin studies may lack validity. In every pair of twins, both individuals share the same environment as each other (because each pair is raised together). However, DZ twins may not share their environment to the same extent that MZ twins share theirs. We assume they do and this is called the equal environments assumption. But the assumption may be wrong because one aspect of the environment is the way twins are treated by others. MZ twins are treated very similarly, especially by parents. DZ twins are treated in less similar ways. This means that concordance rates are inflated and genetic influences on aggression may not be as great as twin studies suggest.  

Ethological explanation of Aggression

Ethologists study the behaviour patterns shown by animals in natural environments. It helps define aggression and looks at how it occurs with other behaviours such as reproduction and threat. Key ethologists are Konrad Lorenz and Niko Tinbergen who believe that aggression has a survival (adaptive) value in animals

Aggression is adaptive

Aggression is beneficial to survival because-

1. It reduces competition - a defeated animal/human is forced into territory elsewhere, so won’t compete for food or mates, etc

2. Establishes dominance hierarchies - dominance over others in your community is adaptive as it brings benefits e.g. for mating and resources

Aggression is ritualistic

• Lorenz formulated the idea of ritualised aggression – the showing of aggression as an assertion of power and maintenance of status.  He said that ritualised aggression usually meant the display of aggression (threat display) but not actual violence

• For example- baring teeth in dogs/wolves and beating chests in gorillas 

Innate Releasing Mechanisms and Fixed Action Pattern

• Innate Releasing Mechanism (IRM) is a neural network that when triggered by a specific ‘sign stimulus’ communicates with motor control circuits to activate the fixed action patterns that are associated with that sign stimulus. Inbuilt biological structure

• Fixed Action Pattern (FAP) is an innate sequence of movements that cannot be altered once triggered. Consequential aggressive behaviour sequence

Characteristics of FAPs (fixed action patterns)

• Stereotyped- the behaviour always occurs in the same way 

• Universal- the behaviour is the same in all conspecifics

• Independent of individual experience- the behaviour is innate 

• Ballistic- once triggered, the FAP cannot be changed or stopped

• Specific triggers- each FAP has a specific trigger (sign stimulus)

AO3 Evaluation: Ethological explanation of Aggression

• Animal research has been generalised to humans, and we should be cautious about doing this to such a complex behaviour (aggression) which is the outcome of many interacting influences (= lower population validity).

• Temporal validity compromise too.  Outdated theory - we don’t need to fight for territory or resources/food any more (in our culture) 

• Biologically Reductionist- Ethological explanations is biologically reductionist because it oversimplifies a complex behaviour down to an evolutionary biological drive. This ignores more holistic ideas/approaches that consider other cultural, environment and psychodynamic factors which have been shown in research to have effects on aggression. A more interactionist approach would be appropriate.

• Research Support- Tinbergen (1951) used male stickleback fish as the subject of his experiment as they were known for their territorial behaviour and red under belly during mating season . Tinbergen presented the sticklebacks with a series of wooden models of different shapes, some with a red spot on the underside and others without. The sticklebacks were placed in an aquarium and observed as they reacted to the models. The researchers noted the aggressive behaviors displayed by the fish, such as attacking or displaying aggressive postures, in response to the models. They found that Male sticklebacks displayed aggressive behaviours. towards models with red spots, even if the model did not resemble a fish at all.  They did not display aggression towards models without the red spot, even if the model looked realistically like a stickleback. This experiment demonstrated that a specific stimulus (the red spot) triggered a fixed action pattern (FAP) of aggressive behaviour in sticklebacks, highlighting the role of innate releasing mechanisms (IRMs) in animal behaviour. It is argued that these fixed action patterns are adaptive because they increase evolutionary fitness. 

Evolutionary explanations of Aggression

Evolutionary explanations state that aggression increases the following:

1. Individual Survival

2. Reproduction 

Therefore aggression has helped evolutionary aims to be met such as gaining resources, food, land, and mates, so is an adaptive behaviour that we will still display today.

Sexual Competition in Aggression

• Males seeking females would have had to compete with other males, one way of eliminating that and ensuring they were successful would have been to be aggressive, through physical competition.  

• Those men that were successful at physical competition would have been more successful at acquiring mates and so would be more successful at passing on their genes to their offspring.

• This has led to a genetically transmitted tendency for males to be aggressive towards other males.

Anti-Cuckoldry Behaviours

• Females- Tend to invest in parental issues, they look for PROVIDERS (to offer time, energy, resources, financial status)

• Males - Tend to compete for the best female/ females with apparent signs of fertility (youthful looks, fertile, attractive) to successfully pass on their genes, also women who seem faithful, to avoid the risk of cuckoldry. 

• Males = Uncertain paternity 

  • A man can never be certain that he is the genetic father of his children unless he prevents his partner from having relationships with any other men.

  • Risk of investing in child -> male worry about sexual infidelity = becomes jealous and therefore aggressive

• Females = Certain maternity 

  • Females are certain that they are the genetic mother of their child and therefore they are not at risk of wasting valuable resources in raising children who are not their own.

  • If the male is involved with another woman there is a potential threat that he might start investing in a new relationship 

  • loss of his time, attention, resources, protection and commitment -> female worry of emotional infidelity = and so become jealousy)

Male Retention Stratergies

• Used to avoid cuckoldry as it is a waste of resources.

• Men in our evolutionary past who could avoid cuckoldry were more reproductively successful, so adaptive mechanisms have evolved to increase anti-cuckoldry behaviours in men.

• This drives the aggressive mate retention strategies men use to keep their partners and prevent them from ‘straying’.

• Direct Guarding and vigilance 

  • A man’s vigilance over a partner’s behaviour (e.g. checking who they have been seeing)

  • Can include coming home from work early, or checking messages on the phone, checking social media posts, etc. 

  • Restricts her movements.

  • Monopolising her time at a party. 

• Negative Inducements 

  • Includes threats of consequences for infidelity.

  • Can be financial control 

  • Threat of violence

  • Actual physical violence (domestic abuse)

Bullying

This could have been an adaptive strategy to increase chances of survival (eg to gain territory, resources, mates, etc).

• Male bullying = physical

  • In men, bullying ensures access to females and reduces threats from other males.

  • Bullying suggests dominance, acquisition of resources, strength and wards off potential rivals.

  • Aggressive bullying was naturally selected as these characteristics would be in more reproductively successful men.

• Female bullying = verbal

  • Bullying in women helps secure a partner's fidelity, ensuring the partner continues to provide resources for future offspring. This takes place within a relationship. 

  • Tends to be verbal - downplaying the attractiveness of any other rival women.

  • Bullying was naturally selected as these characteristics would be in more reproductively successful women

AO3 Evaluation: Evolutionary Explanations of Human aggression

• Temporal validity- This theory is hugely outdated.  Not all relationships are heterosexual.  Some people have no desire to be parents.  Adoption, fostering, IVF means many children are not biologically related to their parents, but loved equally. The validity of this theory for today’s society is very low. 

• Real world application- An evolutionary understanding of bullying as an adaptive response helps us devise effective anti-bullying interventions to increase the costs of bullying and the rewards of prosocial alternatives.

• Social Sensitivity- If aggression is seen as an evolved trait, it may be used to justify violent behaviour, such as domestic abuse, warfare, or male aggression against women, under the assumption that it is "natural" and unavoidable.

• Gender differences- One strength is that evolutionary theory can explain why males and females in their uses of aggression. Lots of research shows that there are gender differences in aggression. Such differences could be due to socialisation but some can be explained in terms of adaptive strategies. Campbell (1999) argues that it is not adaptive for a female with offspring to be physically aggressive because such behaviour would affect her own survival and that of her child. So a more adaptive strategy for females is to use verbal aggression to retain a partner who provides resources. This would explain why women tend to display vernal rather than physical aggression. Therefore, such arguments can provide support for the evolutionary approach to explaining depression. 

• Research Support- Shackelford (2005) Demonstrated a link between mate retention strategies, jealousy and violence. Surveyed 461 men and 560 women. Found a positive correlation between men who used MRS and their use of violence against their partners (heterosexual relationships). There was also a positive correlation in women between those who had jealous partners and being the victims of violence. This suggests that aggression may have arisen as another mate retention strategy, used to deter infidelity, and so supports the evolutionary explanation. However, as this was only a correlation, the nature of the link between the two is unclear, and it cannot be said for sure that they are linked at all. This weakens the support that this study can provide the evolutionary explanation.

Frustration- Aggression Hypothesis

Dollward (1939) suggests that the greater the frustration, the greater the aggression. Aggression is always accompanied by frustration, and frustration always leads to aggression. This suggests a cause-effect relationship between frustration and aggression.

What are the factors affecting the likelihood and target of aggression?

1. Motivation

2. Proximity

3. Is it justified?

4. Displacement

Motivation

Aggression as an outcome of frustration will be more likely if the person is more highly motivated to reach their goal.If they have invested in the importance of the goal, the motivation to achieve the goal will be higher, therefore frustration will be more.

• e.g . queuing for entry to a building when it’s warm outside v’s queueing for entry to a building when it’s rainy and cold.

Proximity

The nearer to a goal a person is before someone/something becomes an obstacle to the goal, the higher the frustration becomes, and therefore, the more likely the aggression. 

• E.g. 15th in queue for lunch v’s 2nd in queue for lunch.

Justified?

A further factor affecting the likelihood of aggression is whether it is justified or unjustified obstacle 

• e.g. a bus not stopping that’s clearly full will lessen the aggression, whereas a bus not stopping that has plenty of room will cause justified aggression.

Displacement

Sometimes it is not appropriate to respond aggressively to the source of frustration e.g. boss/teacher/someone bigger. Instead you displace your aggression on a scapegoat  e.g. your cat/partner/friend.

• Why? … In order to gain a cathartic feeling (expressing ‘pent-up’ frustration) without causing harm to yourself

AO3 Evaluation: Frustration aggression hypothesis

• Research Support for Proximity- Harris (1974) queuing study. Harris used participants who were standing in line at various stores, banks, restaurants, and ticket windows. The experimenter deliberately cut into the line in front of a previously selected person, with that individual being either close to the front of the line or at the rear. The person closer to the front presumably had a stronger drive at that time. The individual's reaction was coded for the severity of the aggression exhibited. In general, the participants displayed more aggression if they had been exposed to the frustration when they were close (proximate) to their objective rather than far away from it. This supports the idea that proximity to achieving goals is an important factor in whether aggression occurs. 

• Research Support for frustration aggression link- Male University students completed a jigsaw puzzle, frustration was manipulated in one of three ways: For some participants the puzzle was impossible to solve. Others ran out of time because another student (a confederate) kept interfering. Others were insulted by the confederate. The participants were then given the opportunity to give (fake) electric shocks to the confederate. All groups gave more intense shocks to the confederate than a non-frustrated control group. 

• Research Support for Justified/Unjustified- Pastore (1952) was among the first to suggest that only unjustified frustrations produce aggressive reactions. In his study the participants were asked how they would respond to various hypothetical situations such as a city bus' failure to pick them up at a regular bus stop. The students answered that they would not become angry if the bus not stopping seemed reasonable or proper. E.g. They said they would not have been bothered by the bus passing them if it had been full. This supports the theory that the source of the frustration is key to whether it leads to aggression or not.

• Issue and Debate- This theory takes a soft deterministic approach to explaining aggression. It actively promotes the idea of choice over what level and type of aggression is demonstrated dependent on motivation, proximity to the goal etc. This is somewhat of a strength - but the theory could be strengthened further with the addition of an interaction of freewill within the theory too.

Social Learning Theory of Aggression

• We learn aggression (it is not an innate/natural behaviour).

• We copy it from others via observational learning

• We learn behaviours from ‘models’ (via ‘modelling’).

• Likelihood of aggression being learnt increases through vicarious reinforcement (indirect rewards felt through the model).

Aggressive Models

• People we look up to/admire

• People we identify with (age/gender/interests/size)

• Teachers, Parents, Older Siblings

• Influential individuals e.g. parents, peers, celebrities, teachers, older siblings

Observational Learning

Observational learning occurs when an aggressive behaviour of a model is viewed and copied - via 4 Mediational Processes:

1. Attention (whether the individual pays attention to model’s behaviour)

2. Retention (whether the individual is able to remember the model’s behaviour)

3. Production (Whether the individual has the physical ability to replicate/reproduce the behaviour)

4. Motivation (Does the individual see a reward for doing that behaviour?)

Vicarious Reinforcement

• If the model is rewarded in a way that you find attractive, you feel the reward ‘through’ the model (indirect reward), and you are more likely to copy the behaviour.

• E.g. a model who bullies gains money/status, the viewer will indirectly feel this reward too.  If it is attractive to them, they will copy this aggressive behaviour.

Self Efficacy

• The extent to which we believe our actions will achieve the desired goal.

• For example: A child’s confidence in their ability to be aggressive grows as they learn that aggression can bring rewards e.g. a child who regularly hits others to get a toy learns that they have the motor skills and strength to do so and this ability comes easily to them

• Self efficacy increases each time aggression brings them rewards.

AO3 Evaluation: Social Learning Theory of Aggression

Bandura (1961) Bobo Doll Study- 

• Sample: 36 boys and 36 girls from the Stanford University Nursery School aged between 3 to 6 years old. 

• Method: 3 conditions- Aggressive adult model shown to 24 children + Non-aggressive model shown to 24 children + No model shown (control condition) - 24 children. Experienced mild aggression arousal by being placed in a room with toys they were not allowed to play with. 

• Findings: 

  1. Children who observed the aggressive model made far more imitative aggressive responses than those who were in the non-aggressive or control groups. 

  2. The girls in the aggressive model condition showed more physical aggressive responses if the model was male, but more verbal aggressive responses if the model was female.  

  3. Boys were more likely to imitate same-sex models. 

  4. Boys imitated more physically aggressive acts than girls did. There was little difference in the verbal aggression between boys and girls.

• Conclusions: Children learn social behaviour, such as aggression, through the process of observational learning - through watching the behaviour of another person. Thus, supporting SLT.

Charlton’s et al’s (2000) St Helena Study- 

• Aim: to assess the impact of TV introduction on the learning of aggressive behaviour in a remote community.

• Sample: School-age children on St.Helena, a small island in the Atlantic.

• Design: natural experiment with repeated measures.

• Method: Children’s behaviour was assessed before and after the introduction of TV for the first time (IV=before/after TV). Aggression was measured through peer and teacher ratings.

• Findings: There was NO significant increase in aggressive play following the introduction of TV, therefore challenging the theory of Social Learning.

Issue and Debate- Social learning Theory highlights nurture factors in aggression (social factors of observational learning, imitating, modelling and reinforcements guide our behaviour). However, it is also known that nature plays an important role in causing aggressive behaviour too (limbic system, MAOA gene, testosterone, also evolutionary features too).  Therefore it could be argued that Social Learning Theory as a theory of aggression is not enough to be a valid theory, and a more interactionist approach, involving both nurture and nature elements would be a more valid explanation of aggression.

Deindividuation in Aggression

The loss of a sense of individual identity and a loosening of normal inhibitions against engaging in behaviour that is inconsistent with internal standards (Le Bon 1895). Deindividuation explains why rational people act differently (aggressively) in groups or in crowds.

In what ways in can a person become deindividuated?

• Uniforms 

• Costumes

• Groups/masks

• Hoods/hats 

• The Dark

• Online

• Whilst Intoxicated 

Reduced Sense of Personal Responsibility

• Occurs in any situation where individual identification is restricted – as changes in normal standards of behaviour can occur.

• Blame and responsibility cannot be given to specific individuals.

• Lower inhibitions may lead to more ‘natural/free’ behaviours, as society can no longer judge individuals (leading to reduced inner-restraint).  

• No need to conform to social roles or expected norms as responsibility is removed. 

• Acting in an agentic state also removes the feeling of personal responsibility or guilt from a behaviour.

Anonymity

Anonymity has the same effect on our behaviour. With no way of identifying you, people cannot hold you personally responsible for your actions. You are free to act in any way you want to. 

Prentice-Dunn and Rogers (1982)

Dunn and Rogers believed that a reduction in self-awarness can cause aggressive behaviours:

• Private self-awareness: A concern we have for our own thoughts and feelings (internal standards & morals). This can be reduced by involvement in activities where we ‘forget ourselves’, e.g. alcohol/drugs/singing & dancing in a group.

• Public self-awareness: A concern about the impression presented to other people – knowing that you’ll be evaluated by them on that basis. This can be reduced by anonymity e.g. online, in a crowd, in uniform, masks/costumes etc.

AO3 Evaluation: Deindividuation in Aggression

Zimbardo’s (1973) Stanford Prison Experiment-

• Sample: 24 male college participants randomly assigned to prison or guard and paid $15 a day.

• Method: Made a mock prison in the basement of Stanford University basement. Participants were in a ‘total institution’ (removed from usual environment & stripped of their identity), in uniforms and hats/mirrored glasses, and in groups. Zimbardo acted as prison superintendent. Guards were instructed to do whatever they thought was necessary to maintain law and order in the prison and to command the respect of the prisoners.

• Findings: Every guard and prisoner at some point behaved in an aggressive manner. There was evidence of much disinhibited and antisocial behaviour. A diffusion in responsibility led to aggressive behaviour from the guards and prisoners.

Gergen et al (1973) Dark Room Arousal Study-

• Sample: 24 subjects (12 men and 12 women)

• Method: A control group of participants were placed into a light room. They were instructed to stay for 60 minutes, and were given no rules as to what to do in the room. An experimental group were placed into a completely dark room. They were instructed to stay for 60 minutes, and were given no instructions as to what to do in the room.

• Findings: Simple conversation took place in the light room. In the dark room; in the first 15 minutes there was polite small talk. By 60 minutes normal barriers to intimate contact had been overcome and 80% of participants ‘got physical’ and were sexually aroused. No aggression was displayed here, so this study challenges the theory that deindividuation causes aggressive behaviours, it does, however, support the theory that a person will feel free to engage in behaviour that goes against social norms and values, and their own moral standards.