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Social Psychology Theories

Social Learning theory

  • Originated Gabriel Tarde (1912) argued the key characteristics of imitation:
  •  The behavior of role models
  • The copying of behavior of those of a higher status
  • The degree of contact with role model
  • The degree of understanding of behavior

 Bandura’s social learning theory

  • SLT is defined as learning behaviour controlled by environmental influences rather than by innate or internal focuses, e.g. genetics.
  • SLT emphasises the importance of observing and modelling behaviours, attitudes and emotional reaction of others.
  • This theory suggests that aggression is learned through observation of others.
  • It also suggests that humans are not born agressive, but we acquire aggressive behaviours in the same way as other social behaviours: through direct experience or by observing the action of others.
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·       SLT is a behaviourist theory, and behaviourists believe:

·       Behaviour that is reinforced (rewarded) will be repeated and learned.

·       Aggression associated with a reward, like praise or increased self-esteem, is likely to be learned.

·       Learning can also occur through vicarious learning, which is when learning occurs indirectly through observing others.


·       Bandura (1963) combines social and cognitive psychology –believed behavior may be motivated by inherent psych factors but also by environmental stimuli- reciprocal determinism: one process or entity relies on another


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Believed there to be 4 basic processes:

·       attention - learning through observation occurs by attending to the model's behaviour. For example, children must attent to what an aggressor is doing and saying in order to reproduce the model's behaviour accurately.

  • Retention - in order to reproduce modelled behaviour, individuals must code and recall behaviour by placing it into long-term memory, enabling the behaviour to be retrieved. In Bandura and Ross's experiement, they found that children where only able to act aggressively as the information was stored in their LTM.
  • Reproduction - individuals must be capable of reproducing the model's behaviour, and thus possess the capabilities and skills neede to copy the modelled behaviour. In Bandura and Ross' study, the children possessed the physical capabilities of hitting and punching the doll.
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  • Motivation and reinforcements - individuals expect to receive positive reinforcements (rewards) for modelled behaviour and this helps to motivate their behaviour. In the Bandura and Ross experiment, children witnessed adults gaining a reward for their aggression. Therefore, the children performed the same behaviour to recieve the same reward.


·       Central part of the process is the presence of a model- this is an individual who seems similar to the child someone who is in a position of power


·       While a role model is important the child requires a certain amount of self efficacy: knowing your own abilities and being confident with them


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Bandura, Ross and Ross (19601)

  • Participants who would see an aggressive model would later reproduce similar aggressive acts to those modeled
  • Those exposed to a non-aggressive model and the control group would not produce aggressive acts
  • Control group participants would actually produce more aggressive behaviour than the participants who saw
  • non-aggressive model, as the latter group is inhibited in their subsequent behavior
  •  Participants are more likely to imitate same-sex models


  • The participants used in the study were 36 boys and 36 girls between the ages between 3 and 5 years)
  • The participants were taken into a room where they were shown how to design a picture at a table in the corner. The model then went to another corner where there was a table and chair, plus an inflatable Bobo doll, a mallet and a tinker toy set. The experimenter told the model that it was their “play area” and the child had no access to it, then left the room.
  •  In the non-aggressive condition, the model played with the toy set. In the aggressive condition, the model played for a minute and then started acting aggressively towards the Bobo doll by (for example), laying it on its side and sitting on it and punching it, and hitting the doll with the mallet.
  • In the control condition, the participants underwent the same procedure except without a model present. 
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      After ten minutes, to ensure all participants were in the same frustrated mood before the next phase of the experiment, they were taken to another room and given more toys to play with. The toys were then taken away from them.

-        Once again, each participant was then taken into another room, where they were given a variety of aggressive and non-aggressive toys to play with during 20 minutes of free play. These toys included a Bobo doll very similar to the one they had seen previously.

-        Their behavior was then observed through a one-way mirror by two judges, one of whom did not know the child nor the condition which they had been allocated

-        condition spent more time sitting quietly, not playing than in the other groups

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  • All of the participants were children between the ages of 37 and 69 months, and they had all been enrolled at the nursery of Stanford University.
  • The children were all matched for their original levels of aggression, in scales of physical aggression, verbal aggression and aggression towards objects
  • The participants were then grouped in threes on the basis of similar aggression ratings, making it a matched pairs design.
  • They were then randomly assigned groups.
  • This ensured an even spread of similar children across each condition, making the results more reliable


  • Children exposed to the aggressive model displayed much more direct imitation than children exposed to the non-aggressive model
  • boys were more aggressive than girls
  •  Watching an aggressive model generally had more of an effect on boys than it did on girls, especially when it was a same-sex model
  • In general, girls spent more time playing with the tea set and colouring books, whilst boys spent it with the gun
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·       Artificial nature of lab- lack eco validity/ behave differently than they would in normal circumstances

·       Cultural bias- only done on Americans cant be generalized to the rest of the pop. Different cultures have different attitudes to aggression

·       Stanford nursery- smart children? Rich upper-class children? – Generalization?

·       Behavior may have been a product of demand characteristics- the child wanting to please the experimenter as children often wish to please adults

·       Bobo doll was specifically made to be punched and kicked –knowledge of this could have furthered this behavior


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  • Helps us understand why children might copy- theory has face validity how behaviors of roles models such as tv characters and op stars can be imitated
  • Burgess and Akers (1966) used SLT to explain deviancy
  • Research focused on society’s attention on the power of the media not just on the areas of aggression 
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  • Imposed etic (researches imposes their view regardless of cultural differences)- he is a western researcher working in a western culture and assumes everyone is the same
  • Views behavior as deterministic-suggest behavior is controlled by either one factor solely or by some general laws 
  • Runciman (1966) belives aggression may be shown due to one’s relative depravition- perceived differmce between what you have and what you think you should have
  • Dollard et al ( 1939) suggested that aggression is not purely due to imitation- aggression is the result of frustration building up(Psychoanalysis) and the presence of  environmental cue
  •  Bandura and Watson: learning takes place regardless of reinforcements.

  •   Phillips (1986) found that daily homicide rates in US almost always increased in the week following a major boxing match; suggesting people were imitating behaviour that they had seen.

  • Cultural differences; some culture not violent, or can channel aggression so it is a positive thing. 

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Zimbardo (1969)

  • Zimbardo (1969) showed the effects of reduced inhibitions.
  • Used female undergraduates in a study of learning.
  • Stooge(confederate) played student, participant played teacher. ‘Studen’t had to complete set of tasks, electric shocks were delivered to the ‘stooge student’ if they completed tasks wrongly. (similar to Milgram) 
  • Half P’s were wearing large lab coats and hoods to cover their faces.
  • Groups of 4 never referred to by name and were the deindividuated group.
  • Others wore normal clothes given large nametags introduced to each other formally.

·        Deindividuated participants delivered twice as many shocks as individuated ones.

·       Child of its time (people may be more self aware now a days?)

·       Perhaps as females they gave lower shock than what male would have

·       Students- cannot be generalized to the rest of the population


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Deindividuation: the loss of one’s sense of individuality

The loss of ones’ sense of individuality/ decreased self-assessment and awareness in a situation where identification of an individual is difficult if not impossible.

·       Singer, Brush and Lublin (1965) showed that when inhibitions are lowered in a group the topic of conversation can change very dramatically. In a discussion of *********** men were more likely to contribute when they were made clear that their identity had been reduced- only men (women may be less forth coming )/ child of its time(people are more willing and free thinking) perhaps if something that was taboo in certain times such as metal illness it may have the same effect

·       Zimbardo suggested that sensory overload, altered state of consciousness, level of arousal and reduction of responsibly could have an effect on antisocial behavior ( increasing the likelihood of it)

·       Diener (1976) conducted a naturalistic observation of 1300 trick or treating children in US. When in large groups and wearing costumes to hide identity more likely to perform antisocial acts such as stealing money or treats.

·       Silke (2003) analysed 500 violent attacks occurring in Northern Ireland. Of 500, 206 carried out by people who wore some sort of disguise so identity unknown. Also severity of attack was linked to whether perpetrator was masked or not


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Evaluation of the deindividuation

  • Not all crowds or groups are aggressive – Gregen et al ( 1973) lowered levels of deindividuation did not result in aggressive actions
  • Bloodstein (2003): noted that ppts who had speech problems such as stuttering showed fewer of these problems when wearing a mask – increased self efficacy due to hidden identity and decreased opportunities for evaluation apprehension
  • Mullen (1986): showed that in violent situations where people where being attacked, individuals who went to help them would do so if they could mask their true identity
  • Watson (1973) studied 24 cultures, warriors that disguised their true identity through the use of face paint tended to use more aggression and increase of torture, death or mutilation of captives
  • Postmes and Spears (1998):meta analysis- did not find a consistent finding of deindividuation acting as a psychological influence on peoples state of behavior contradicting previous trains of thought . Found that behavior in groups has more to do with group norms. Proves there is no consistent research that shows being in a group increase ant-social behavior due to anonymity
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Cue Arousal- there needs to be a cue or a stimulus to spark aggression

·       Berkowitz and LePage argued that if cues such as a gun or a knife are presented they will influence an individuals behavior turning anger to aggression

Berkowitz and LePage (1967)

  • 100 undergraduate Psychology students (US)
  • Can just seeing a firearm trigger aggression?
  •  Each ppt paired with a confederate –told they were taking part in a physiological task looking at stress
  •  1st condition: ppt placed in one room + confederate placed in adjoining room and given mild electric shocks
  • The amount of hocks given was indicative of the performance
  • Those who received the most shocks were in the angry group
  • The group that wasn’t angry only received one shock
  • In the 2nd aprt of the experiment the confederate and ppt changed room-the real partner now had to judge their partner performance
  •  In some cases a gun was left in plain view .In another a badminton racket and shuttle **** was present
  • The number of shocks administered was measured
  • Angry subjects with fire arm present gave more shocks than badminton condition
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  • Artificial environment- not an everyday task (lacks ecological validity)
  •  Behavior not normal- DEMAND CHARACTERISTIC
  • No consistent replications with similar results made
  • Consequentiality- possible that the results were only affected because eit wa sonly just one study
  • Kleck and McElrath (1991) looked at 21 weapons effects studies and stated that the effect only worked with those who had never experienced a gun before – also the more the experiment reflected real life the less likely there would be an effects
  • The consequences of the experiment or neither serious nor permanent
  • Ppt deceived
  •  Trauma in giving another person a shock
  • The shocks were real – trauma – inflcting pain onto another person
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Evaluation of cue arousal




·       Theory ignore individual differences

·       Not many studies further support Berkowits and LaPage

Provide a more logical explanation for the frustration/aggression theory


·       Ellis,Weiner and Miller (1971)did a similar experiment and found that results were the complete opposite-further reinforced by Cahoon and Edmond

·       Has more biological and cognitive explanations that have not been explained – multidimensional explanation


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Relative Deprivation:

  • Hovland and Sears (1940) noted that during the depression in the US there was a increase in the anti-black behavior such as lynching’s
  • Stouffer (1950) advanced the first formal attempt by forming a relative deprivation theory
  • Expressions of anger in groups often come about from inequalities e.g. the lose Angeles riots 1922
  • One sees what the other group has and believes they should have it to- the difference between what they think they should have and what they actually causes grounds for relative deprivation
  • Runicimann(1966) fraternalistic  deprivation: the inequality and injustice experienced collectively as a group in comparison with other collective groups
  • He differentiated this from egoistic deprivation: the inequality and injustice experienced when you compare yourself to other individuals
  • Wright and Klee(1999)believed that reducing the difference between individuals and groups would reduced relative deprivation thus reducing the aggression experienced


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Evaluation of relative deprivation:


  • The race riots of Chicago- 1919 due to perceived inequalities between groups
  • ·       Been applied to other situations:Kanin(1985):examined date rapists-the individuals heighted need for sexual contacts and acts is not met by their ability to achieve these- mismatch between wants and needs


  • Says very little about how we decided to what group to compare ourselves with- RD seems to ignore the cognitive processing and rationalization of these decisions
  • ·       Not every acknowledgment of a group difference does not lead to aggression

    Can lead to people wanting social change through acting in a positive manner such as social movement – movement ot make the ghetto more creative?
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Evaluation of social psychology:

  • Most of these experiments have taken place in a lab setting- lacks ecological validity as it may not represent how people act in normal everyday situations
  • Demand characteristics within a lab setting
  • Social desirability- people are aware that aggression is not always socially acceptable and therefore may react differently in order to be perceived as socially ‘normal’
  • Orne (1962): noted ppt are often helpful towards the experimenter-sometimes too helpful (how can being to helpful be perceived –people may have different perception) which they believed to be a confounding variable within the Bandura Bobo doll experiment
  • Explanation is to simplistic
  •  Little consideration of environmental factors that could influence aggression-such as aggression
  • Farah (2000): studiedovercrowding in refugee camps in the West Bank – increase in violence when there was overcrowding                              
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Explanations of institutional aggression:

1.      Situational forces: a general term referring to those factors presented in social situations that collectively encourage the showing of certain aggressive behaviors that would not otherwise be seen

2.     Individualistic (dispositional forces): those characteristics of an individual that contribute to them showing behaviors usually regarded as antisocial or aggressive

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 Situational Forces:

Zimbardo’ (1971) standford prison exp.

  • Method:  24 Male students  who volunteered were recruited to act as either guards or prisoners in a mock prison. Randomly assigned their roles, and behaviour was observed. Arrested at home, given uniforms and numbers. Guards wore uniforms and mirrored sunglasses to avoid emotion being involved.
  • Results:  Initially, guards asserted authority and prisoners resisted by sticking together. The prisoners then became more passive and obedient, while the guards invented nastier punishments and it was eventually abandoned early due to distress. Guards and prisoners adopted their social roles quickly, Zimbardo claims our ‘social role can affect our behavior’. Seemingly well balanced men became unpleasant and aggressive.
  • One of the guards (Hellman) was very brutal so his physiological and psychological state was investigated and no abnormalities were found .Also they had no preference for being a guard or prisoner so maybe it was the situation he was in that corrupted his normal way of thinking
  • Evaluation: Good control of variables. Can’t be generalized to real life situations. Distressing, so ethics is a big factor. Problem with observer bias, as Zimbardo participated, and later admitted he became to personally involved in it. Doesn’t take individual differences into account, not all ppts behaved the same.
  • McCorkle et al found that over crowding, lack of privacy and lack of meaningful activity all significantly influence peer violence.


·       Research into psychiatric units found that increased personal space did not decrease the level of violent incidents among patients.


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Real life example of situational forces:

Abu Ghraib jail Iraqi prisoners of war subjected to degrading & dehumanizing treatment

The behaviors witnessed were a result of several factors interplaying

  • Status and power: those involved were army reservists with little or no power of their own-they were trying to demonstrate some control over anything inferior to them. Also there was no superior officer checking on them
  • Revenge and retaliation: revenge for hurting and killing fellow us soldiers
  • Deindividuation and helplessness: they showed behavior instantaneously in response to a situation without any planning or thought for the future negative consequence

Individualistic causes:

  • Abu Ghraib- not the group forces but particular ‘bad eggs’ that are not representative of the whole not the result of a system or institutions
  • Suggesting that there are aspects of ones personality that makes them more prone to aggressive outbreaks
  • One problem with this view is that we don’t understand human behavior fully- the view holds the belief that we are rational and have moral values that we up hold but this may not be the case
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The importation model claims that aggression occurs within institutions because of the characteristics of the individuals within the institution.

  • Personal and psychological characteristics are brought into the institution by the individual and these characteristics determine how much aggression each individual displays.
  • If there are enough individuals who were aggressive before prison then this will become the norm and aggression will be more likely.
  • Many inmates in prisons have may have characteristics that would predispose them to aggressive behaviour.
  • Kane and Janus: conducted research that found that non-whites and younger prisoners are more likely to behave violently than other groups, they also found that those who had long periods of unemployment and low levels of education were more likely to use aggression, however this could also support the deprivation model as these people may feel deprived as an effect of unemployment and poor education leading them to become aggressive. 
  • Toch :‘all prisons inherit their sub-cultural sediments from the street corners that supply them with clients’. This means that individuals bring their aggressive behaviour to each new setting they find themselves in.
  •  Mills: found inmates who had a higher level of alcohol dependency were associated with greater levels of aggression.
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  • most of the evidence is correlational and therefore a direct link between personal characteristics and Institutional aggression cannot be assumed.
  • much of the research into institutional aggression has been carried out in prisons it can’t be generalised to other institutions as many inmates have already been shown to be generally more aggressive than the rest of the population.
  • Culture biased as it was carried out either in western prisons or prisons run by western powers and therefore is only applicable in those types of institutions.


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Applications of research:

1.     Security forces:

Bernard’s theory of aggression in the sub-culture of the police force-argued that factors such as chronic stress along with the inability to respond to the actual source of stress leads to frustration and aggression

Wesley (1970): advances Bernard’s idea stating that aggression is seen as acceptable and in some situations is expected due to the particular working environment

Robert Agnew’s (1992): supports this assertion – the general strain theory suggest that negative experiences and stress generates a negative affective state that in the absence of coping strategies may lead to aggressive outburst

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2.    Terrorism:

Black (2004): says that pure terrorism is unilateral self-help by organized civilians who covertly inflect mass violence on other civilians  -Idea suggests the motives behind terrorism are to improve a current situation and this is done by imposing negative behavior on a mass scale applying the principle of collective liability (targeting radon civilians rather than the military). Believes that current terrorism is due to culture clashes

Deflem (2004): the division between situational and dispositional factors may not be as clear as previously thought

Barrack ( 2004): looks at suicide bombings and believes them to be more of a dispositional force

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The Role of Genetic Factors in Aggressive Behaviour

Selective breeding: This involves choosing animals with aggressive characteristics and mating them with others to enhance this trait. This has a long history, e.g. Spanish fighting bulls and fighting *****.


·       Lagerspetz (1979) selectively bred mice to be 50% more aggressive than normal mice within 19 generations. They had heavier testes and forebrains and altered levels of neurochemicals, serotonin and noradrenaline.

·       Lagerspetz (1981) points out that genetic factors do not absolutely determine aggression since selectively bred aggressive mice can be conditioned to be less aggressive, and also aggressive wild animals can be tamed.

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Twin Studies:

  • As selective breeding in humans is not possible, the next best thing is to study people with known genetic factors - i.e.twin studies, especially twins reared apart.
  • As humans are much more biologically complex and also live in more complex environments, discriminating between genetic and environmental influences on human aggression is very difficult.
  • A meta-analysis by Miles and Carey (1997) suggested heritability of 50% for aggression, but Plomin et al (1990) estimated a much smaller heritability.
  • Canter (1973) found a small correlation of 0.14 for MZs reared together, but O`Connor (1980) found a correlation of 0.72 for the same population.
  • This variability may be due to differences in methods of assessing aggression
  • e.g. Rhee and Waldman (2002) found heritability estimate was 39% for self-reported aggression but 53% when reported by others.
  • However, studies consistently show greater similarity of aggressiveness in MZs than DZs, indicating a genetic contribution.
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XYY syndrome:Some men have an extra male Y chromosome, and since males are more aggressive than females. This suggests further aggression in XYY males.


·       Jacobs et al (1965) found the incidence of XYY syndrome was 3% in a prison population compared to 0.1% of the normal population. These men were taller, had higher levels of testosterone and lower intelligence levels.

·       Witkin et al (1976) could find no link between XYY syndrome and increased aggression in prison inmates, but did find lower levels of intelligence. Inspection of crimes showed that they were not more violent in nature but they were poorly planned. The researchers suggest that lower IQs in XYYs make them more likely to be caught, hence more of them in the prison population.

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MAOA gene and aggression:Several studies have linked aggression to the monoamine oxidase A (MAOA) gene, which regulates the enzyme monoamine oxidase A. This enzyme breaks down several important neurotransmitters (e.g. serotonin, dopamine) which are associated with mood.


·       Brunner et al (1993) discovered a defective MAOA gene in Dutch family with a history of male violence which means they had a deficiency in MAOA. The gene was passed on to men from the X chromosome of their mothers. Only men were affected because they have only one X chromosome, whilst women have two.

Cases et al (1995) disabled the MAOA gene in the X-chromosome of mice and found that without the mono-amine oxidase A enzyme, levels of dopamine and serotonin increased and males became highly aggressive females were unaffected. Restoring the function of the gene returned male mice to a normal state

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Different forms of defective MAOA gene have been identified:

·       MAOA-L is a low activity form that produces less of the monoamine oxidase A enzyme.

·       MAOA-H is a high activity form that produces more of monoamine oxidase A enzyme.

Research shows that the MAOA-L gene in particular is related to aggression.

·       In an fMRI study Meyer-Lindberg et al (2006) found reductions in volume of amygdala and prefrontal cortex in MAOA-L compared to MAOA-H participants. These brain areas are often to be impaired in anti-social individuals.


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The role of neural and hormonal mechanisms in aggression

  • Androgens: male sex hormones (testosterone)
  • Leydig cells: a system of cells in the testes that make testosterone
  • Circadian rhythm: biological rhythms with a cycle length of 24 hours
  •  Basal model of testosterone: the model that suggests that an individual’s level of testosterone influences their level of dominance.
  • Reciprocal model of testosterone: reverse of the basal model and suggests that testosterone levels are influenced by changes in the of dominance that an individual
  • Serotonin 1B receptor: (HTR1B) neurotransmitter that acts in the central nervous system inducing behavioral changes
  • CSF: cerebrospinal fluid-colorless solution that bathes and protects the brain and spinal cord
  •  Tryptophan: an amino acid found in food that is essential to the production of the neurotransmitter serotonin in the brain
  • Serotonergic: containing or releasing serotonin.
  • Amygdalectomy: surgical removal of the amygdala.


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Hormonal Influence on aggressive behavior



·       General positive correlation between androgen levels and aggressive behavior in male and female prisoners.

·       Methodologically such assertions weaken since levels of androgen are not measured at the precise point when the aggressive at was performed.

·       Testosterone is androgen produced by the Leydig cells in male testes and adrenal cortex.

·       Release of hormone is based on natural circadian rhythm

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  • Kimura (1999)Female spatial ability tends to improve with increased levels of testosterone. Therefore the outcome of high levels of testosterone does not always lead to increased levels of aggressio
  • Simpson (2001)Argues that  testosterone is only one of a myriad of factors that influence aggression and the effects of environmental stimuli have at times been found to correlate more strongly 
  • Harrison et al (2000)Noted that after giving men testosterone to 56 men (20-50), when given a frustration inducing computer game, aggressive responses were increased. However the effect is not the same for the entire sample. If anything, the changes were largely psychological and few had any noticeable physical effect on behavior
  • Huston et al (2007)Increased levels of testosterone led to better performance in competitive tasks and worsened performance in cooperative tasks

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  • Wagner, Beuving and Hutchinson (1979)Castrating male mice. Led to overall levels of testosterone decreasing. Normal levels of aggression then came about when mice were injected with testosterone. This suggests testosterone has a strong hormonal influence over aggression levels. But castration must take before puberty before aggressive behavior becomes established.
  • Evaluation: Only Correlational/ does not show cause and effect
  • Pillay (2006)

    Noted that testosterone has been associated with varying athletic qualities. Studied 94 athletes whose testosterone levels differed according to which sport they played. Level of testosterone was measured ins saliva and found that males and females in aggressive sports had the highest level of testosterone
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  • ·       Suggests that testosterone causes a change in a person’s level of dominance. The more testosterone a person produces the more competitive and dominant they will become. Therefore in an attempt to express their dominance they become more aggressive. Therefore it follows that an increase in testosterone may lead to more antisocial behavior such as fighting
  • Mazur and Booth (1998): men with high TSTR – more likely to divorce o remain single; use weapon in fights; have bad debts.

 Reciprocal model of testosterone

  •  Suggest that testosterone levels vary with the person’s dominance. The level of testosterone I the effect and not the cause of dominance.
  • Mazur and Booth (1998): 2,100 air force veterans were studied over a 10-year period and were given 4 medical examinations. Found that testosterone levels varied- reduced when married and increased when divorced


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Serotonin and Aggression

·       Serotonin is a neurotransmitter (also called 5-hydroxytryptophan or 5HT) 

·       Davidson et al. (2000) suggested that serotonin may provide and inhibitory function- when comparing violent criminals to non-violent one the level of serotonin was very low.

·       Mann et al (1990) administered dexenfluramine to 35 healthy adult volunteers. Dexenfluramine is a drug that depletes levels of serotonin in the brain. The findings were that males, but not females, exhibited greater levels of hostility and aggression after taking the drug.

·       Lenard (2008): low serotonin levels in the brain can cause impulsive behavior, aggression, overeating, alcohol abuse and violent suicide


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Supporting animal research:

·       Mice who did not have a functioning serotonin 1B receptor was not functioning found an increase in the aggression.

·       Vervet Monkeys- reducing the level of serotonin in monkeys resulted in an increase in aggression, where as an increase in the level of serotonin led to a decrease in the level of aggression

·       Comparisons of Russian tame silver foxes to wild ones show that tame foxes have higher levels of serotonin, tryptophan hydroxylase (used to create serotonin) and low levels of MAOA.

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·       One problem with using animal studies to research the effects of testosterone is that certain brain structures are involved with different types of aggression in different species. For example, the cingulated gyrus is linked to fear-induced aggression in monkeys and to irritability in cats and dogs, which creates problems when trying to generalize the findings to humans.

·       Castration research usually indicates that the reduced levels of testosterone lead to reduce aggressive behavior. However, castration disrupts other hormone systems as well, so these may play a part too.

·       Ethical concerns using animals- testing on species that feel pain – questionable?

·       Cannot generalize research done on animals – however does provide a basis on which to base scientific human resreach

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  • Linnoila and Virkunen (1992) found a relationship between low levels of serotonin and highly explosive violent behaviours, suggesting that a lack of serotonin is linked to aggression
  • Tryptophan is combined with desyrel 5 HTP (SEROGENIC DRUG) usually given to juvenile delinquents and unpredictable patients (Mornad et al 1983 and Greenwald et al 1986 respectively)
  •  Albert et al (1993) found that raising testosterone levels in female rats elicited aggressive behaviour in the presence of certain environmental events, such as competition, suggesting that testosterone alone is not responsible for aggression as it requires certain environmental triggers.
  •  Higley et al (1996) reported that individuals with raised levels of testosterone exhibit signs of aggression, but rarely commit aggressive acts, suggesting that social and cognitive factors play a mediating role.
  •   Summers et al (2005) globally acting serotongenic drugs do act to reduce aggression but this cannot be singularly as the only cause
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·       Ethical treatment of human participants

·       Although strongly linked to aggression, testosterone is only one factor and the effects of previous experiences and environmental stimuli have been found to influence aggressive behavior more strongly.

·       Results from human studies are often subjective, relying on questionnaires and observations.

·       Ignores the role of the structure of the brain- Phineas Gage

·       Ignores environmental factors – e.g temperature/ overcrowding and noise all have an effect of showing aggressive behavior

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Brain structure and aggression


  • Brad and Mountcastle (1948) looked at rage in cats caused by a detachment of the higher and lower brain through lesioning. Concluded that  it is the hypothalamus that initiates aggressive behavior and cerebral cortex reduces this behavior .
  • Flynn( 2006): stimulating the lateral hypothalamus in cats more likely to show predatorial  aggression but when the medial hypothalamus was stimulated  this encouraged viscous attack behavior


  • lesioning of the amygdala of aggressive animals was shown to have taming affects
  • Amygdalectomy is used to reduce violent behavior in humans – however there is an emotional loss

Frontal CortexSocial regulation and social interaction (aggressive behavior is apart of this) are functions that involve the frontal cortex

·        with frontal lobe damage often show impulsive behavior, irritability, shortness of temper and are easily provoked

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Case Study: Phineas Gage (Harlow 1868)

  • Railway worker – tamping iron entered the left side of Gage’s face, passed through his jaw, up and behind his left eye
  • Noticeable changes in his personality
  •  Unable to stay in a job for very long
  •  Became aggressive
  • The longitudinal study of the damage to his frontal lobe provided evidence that the brain affects personality and social behaviors.
  • Cannot be applied to general population
  • Gender – It was gender biased as the study was limited to a man and at the time they did not know that both men and women’s brains worked the same?
  •  Unethical?
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Animal Research

·       Zagrodzka et al (1998) using cats showed that damage to the central nucleus of the amygdala contributed to predator like attacks.

·       Potegal et al (1994) :involved rats. The corticomedial amygdala was identified as potential center for mediating and regulating aggressive reaction

·       Potegal ( 1991): showed that hamsters have more active neurons in and around the medial nucleus of the amygdala during acts of aggression. No other increases in other parts of the brain

·       Potegal argued that differences in humans and animals were qualitative (generally the basics are the same but the details are different) therefore results can be generalized to humans

·       This assertion is supported by Blair et al (2001) studied aggression in institutionalized humans due to psychopathic tendencies .Proposed that psychopathy  involves damage to the amygdala.


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Cultural Differences:

  • Focusing on only the biological aspects of aggression ignores the fact that culture may have an influence.
  • Mead (1935): Arapesh tribe learn aggression through he act of socialization 
  • Anderson et al ( 2000) argue that aggression might be learned though observing the various forms of media available  to people

 Situational Factors:

  • Bio also ignores situational factors
  • Bushman (1993,1997) and McDonald et al (1996) show how alcohol disrupts information processing – an accidental comment can be interpreted as meaningful, therefore contributing towards aggressive behavior
  • Temperature/noise/overcrowding can explain aggression
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Evolutionary explanations of human aggression

Aggressive Behavior by animals

  • Lorenz (1966): stressed that humans are animals and therefore show similar behavior patterns.
  • Main drive for aggression: fear/reproduction/hunger
  • Believed it could only occur within a species and not between

The functions of aggression:

  •  Ensures only the fittest survive leading to the fittest and strongest males and females being selected for reproduction- higher chance of survival for offspring
  • Ensure survival of young- parents are protecting
  • Help the distribution of a species as they have territories
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Formulated the idea of ritualized aggression: the showing of aggression as a basis for the assertion of power and maintenance of status

·       Little harm was observed as a result of ritualized aggression e.g. when stags show rutting behavior

  •  Morris (1990):  states that animal disputes show remarkable amounts of restraint
  • Gross (1998): when 2 jackdaws are about to attack watch other they show appeasement tactic (behavior that if shown stops the aggressive act by the competitor- admitting defeat) e.g showing the nape of the neck
  • Barnet (1973): sttes that lorenz’s work does not represent current methods and opinion in ethology
  • Lorenz’s view is outdated and oversimplified
  • Lerham (1953): questions whether it is correct for a researcher to draw parallels between non-humans and humans – although behavior may seem the same we cannot assume that the underlying behavior is the same
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Aggressive behavior by humans:

·       From an evolutionary perspective, humans are most likely to survive if they have access to resources; they can defend their resources and protect their families; and if they can attract and gain access to mates.

Lorenz’s view:

  • Benign aggression: similar to animal aggression, it involves an impulsive act if threatened 9parent protecting child from harm)
  • Malignant aggression: an evil act, not instinctive (organized gang warfare/crime)

 Nelson (1974): factors that affect aggression

  •  The process of learning: bandura  shows aggressive behavior can be learnt through watching others
  •  Structural causes: nature of social life –a society with norms would lead to widespread violence
  • Psychological causes: highlight the failing of the bio approach- often in the animal kingdom aggression is expressed to a specific enemy- but in humans this is often not the case since aggression can be motivated by many personal and situational factors
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  • Fromm (1964): in some acts of human-human violence the victim is no thought of as human
  • Tinbergen (1968):while humans like animals may fight each other humans are the only species in which aggression is not part of an elaborate ritual

 Aggression in Males:

  • Males are motivated to acquire status since high status males have access to mates and resources for survival.
  • High status males are more likely to be selected by females since such males will be better able to guarantee the survival of her and her offspring.
  • Low status males have to engage in high risk strategies to enhance their chances of reproduction.
  • Daly and Wilson (1985) - a review of murders found that the motive behind most conflicts was status. The victims and offenders were most likely to be men of low status and without a mate (unemployed and unmarried). Most victims/offenders knew each other so understood the status of their rival. Those of equal status were more likely to resort to aggression to a bid to move their status above their opponent.
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Aggression in Females:

·       Females are generally viewed as less aggressive since the costs of such behaviour outweigh the benefits.

·       It is more important for the mother to survive because her presence is more critical to the survival of offspring than the faster.

·       Hill and Hurtado (1996) - among the Ache of Paraguay, children are 5 times more likely to die if the mother dies, and 100% likely if this happens before the child is one year old.

·       Griskevicius et al (2009) have shown that sex differences in aggression exist for both direct physical aggression (men exhibit more) and for indirect, verbal and psychological aggression (which females make more use of).

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Infidelity and jealousy:

  • A woman can be 100% certain that the child she carries is hers, but a man has no such certainty. Sexual jealousy therefore has evolved to help males protect their investment. 
  • Daly and Wilson (1985) - found that sexual jealousy was the underlying factor in 58 out of 214 cases of murder.
  • Male aggression against females is designed to deter females from indulging in behaviour which is not in the interests of the male. 
  •  Brunk et al (1996): suggest that from a male’s point of view infidelity of a woman brings about uncertainty of paternity as well as a sense of sexual jealousy
  • Also states it is the lack of emotional support that makes women aggressive whilst in men the anger is based on suspecting the wife’s infidelity
  •  Bellis and Baker (1990) estimate that 7 to 14% of children are not fathered by the mother's husband or partner. 
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  • Miller (1980) - of 44 battered wives living in a women's hostel in Canada, 55% cited jealousy as the reason for their husband's behavior.
  • Male aggression may also occur in response to a threat from a rival suitor.
  • Young (1978) - asked to describe their likely reactions to a jealousy-inducing situation in a film, men predicted anger, drunkenness and threatening behavior. Whereas, women predicted crying not to care and increasing their own attractiveness
  • Cascardi and Vivian (1995):  found that the main cause for aggression in a relationship is sexual jealousy
  • Canary et al (1998):couples with relationship conflicts often reported  that anger and aggression contributed to the jealousy
  •  However it may be some aggressive males lack the ability to mediate and respond to situations of jealous
  • Harvey et al: shows that the causes of jealousy are often multidimensional 
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Issues debates and approaches (IDA)

Much research makes use of questionnaires and surveys to collect data

Surveys are a self report method and therefore has inherent difficulties with collecting reliable and valid data. If a man is asked to complete a questionnaire asking how violent he is towards his partner, then it is most likely that he will distort the truth due to his desire to appear more socially desirable than he actually is (social desirability bias). Similarly, a woman may be less likely to accurately report her partner as abusive if she fears recriminations from him, or she may even choose to deny the truth about his behaviour because acknowledging it could mean the end of her relationship with him. Questionnaires and surveys may not therefore reveal the true extent and nature of male jealousy.

·       Research into infidelity is gender biased :The evolutionary argument for infidelity states that it is something a man must prevent a woman from doing, and does not really acknowledge the fact that men may be just as unfaithful as women. This is heavily gender biased and does not reveal the true nature of male and female infidelity.

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·       Nature nurture debate

Evolutionary explanations argue that behaviour has evolved through gene selection and is therefore biological. If jealousy and uxoricide were really evolved responses to female infidelity and determined by genes, then we would expect all men to behave violently to women, but clearly they do not. There must, therefore, be an alternative explanation that takes into account the fact that men may have naturally aggressive responses to female infidelity, but that also explains why many men do not behave violently and others do. Social learning theory may account for this as violent men may have grown up with violent role models, and have learned to be violent by observing them.






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Explanations of group displays of aggression:

Group display and war: Freud said that the mind set of an individual changes within a group, their minds merge based on shard opinions. The enthusiasm of being in a group reduced inhibitions

Convergence Theory

  •  Turner and Killian 1957 said that the motive behind group behaviour is the convergence upon a specific location by like-minded individuals. (Football crowd)
  • Emergent Norm Theory :Crowd behaviour is normless, because the situation is unique
  • A person who act in a distinctive way within the crowd with get noticed because the crowd is normless
  • This distinctive behaviour will then be taken on as the norm for the group
  • The crowd think logically as a mass of individuals
  • Crowd behaviour can be unpredictable because it is governed by the norms identified and accepted by the group
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Influence from the Group

-        Le Bon 1896 suggested that group behaviour was the result of individuals’ behaviour

-        The atmosphere of the group cases contagion which makes the group members suggestible to the views and actions of others within the group.

-        Group behaviour is taken up quickly which creates a ‘group mind’

-        Blumer 1939 said that a circular reaction takes place in which the individuals reproduce behaviours of those around them which then intensifies the original emotion and behaviour. He said this is the reason for social unrest


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-        Levy 1989stated that every explanation of group behaviour takes a different perspective.

-        Freud failed to use hypothetico-deductive method for his theory so it is not validated

-        Le Bon’s theory is criticised by the fact that groups do not take on a mind-set of their own that is different to every one of the individuals within the group.

-        The convergence theory is good because it focuses on how groups consist of like-minded rationally thinking individuals

-        Emergent norm theory provides an explanation for most crowd behaviour, but it does not explain exactly how norms might emerge within a group

-        The Emergent norm theory does not take into account non-verbal processes, which occur within a crowd.

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Value added Theory:

Smelser (1963): suggested certain prerequisites were needed in order for a group or social movement to develop

  •   Structural conduciveness: conditions must allow for collective action
  • 2.     Structural strain
  • 3.     Growth and spread of generalized belief-causes and determines a response or action
  • 4.     Precipitating factors: collective belief is strengthen the search for alternatives gathers pace
  • 5.     Mobilsing the collective for action-hierarchy of order
  • 6.     Reaction of agencies of social control
  • ·       Argues that if society norms are not regulated it will change how the individuals view on the appropriate behavior
  • ·       If rewards an incentives are given selfishness may prevail rather than general respect for others
  • ·       Human behavior is often the result of net regulation on a societal level
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Evaluation of theories of crowd behavior:

·       Freud’s theory has been criticized for not following the hypothetico-deductive theory (the basic structure of a scientific experiment – hypothesis then investigation then conclusion)

·       Many factors effect group behavior and it cannot be simply just one

  • Support from everyday experiences. Everyday experience provides support for the fact that aggression is a form of social behaviour rather than always an expression of anger.
  • Support from research. Studies such as that of Blumenthal et al. (1972) support the view that our judgement concerning whether or not someone is behaving aggressively depends on the constructions we place on behaviour.
  • Support from research. Studies such as Brown and Tedeschi (1976) support the assumption of the social constructionists that our judgements are based on social norms.
  • Exaggerates the extent of interpretation. Social constructionism overemphasises the role of constructions in people’s judgements of whether an act is aggressive. There are cases in which there would be virtually unanimous agreement that an act is aggressive.
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Lynch mobs

  • ·       Myrdal (1944) suggests that the fundamental cause of lynching in the US was fear of the Negro, which led white mobs to turn to ‘lynch law’ as a means of social control.
  •   Patterson (1999) claims that lynch mobs were more active during this period because it was a time of major social transition (after the collapse of the slavery) where entire communities felt at risk
  •  Power-threat hypothesis: racist myth of Negroes’ uncontrollable desire to **** white women was frequently used in defence of the lynching practice, although homicides and assault frequently cited threats to the majority group.
  • Blalock (1967) power threat hypothesis which says that groups that pose a threat to the majority are more likely to be discriminated against.
  • Boyd and Richerson (1990) provide evidence to support the power of social conformity within group behaviour. They discover that groups in which cooperation thrived were also those that flourished. This provides an explanation why a majority group is more at risk as a consequence of social change; individual self-interest would give away to ‘groupishness’.
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Nature of social threat is poorly defined. Lynchings in brazil,

Clark (2006) concluded that the evidence contradicted the claim that the threat of ‘dangerous classes; in society was a major causal factor in Lynchings.

Sports events and Xenophobia

  •  Wilson (1975) claims that xenophobia has been documented in virtually every group of animals displaying higher forms of social organisation.
  • Natural selection has favoured those genes that cause humans to be altruistic towards members of their own group but intolerant towards others.
  • Shaw and Wong (1989) argue that mechanisms that prompt suspicion towards strangers would be favoured by natural selection. This would have enabled our ancestors to avoid attack and so leave behind more offspring.
  • MacDonald (1992) suggests that from an evolutionary point of view, it is adaptive to exaggerate negative stereotypes about outsiders as the overperception is better than under


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Sports crowds:

·       Hockling(1982):observed a basketball game-convergent theory explained similar behaviours shown by a crowd. Booing behavior explained by contagion theory where as standing up of all the spectators refers to emergent norms

·       Guttman noted that there is no single one appropriate theory for group displays of aggression in sports crowds


Crowd Celebrations:

·       Cassidy et al (2007): investigated the Hindu festival Mela which is one of the largest gatherings of humans on earth and is a peaceful celebration –crowds behavior increased/ more generosity/ support of others


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