The SLT has supporting research to suggest that there is a difference in cross cultures. For example, Margret Mead observed the Mundugumor and Arapesh tribes from New Guinea and found that the Mundugumor were highly aggressive and had a history of killing outsiders for cannibilism. However, men and women of the Arapesh were non aggressive and would hide rather than fight. TST the SLT can account for aggression and it suggests that it is a porduct of nurture as differences have been found cross culutrally.
There are controversies in the idea that violent video games lead to aggressive behaviour in real life. The SLT would argue that aggressive behaviour in video games would be modelled if they are percieved as being successful. For example, Anderson and Dill found that those who reported playing more violent video games when school age, also admitted engaging in more aggressive real-life behaviour. TST playing violent video games can have a long term effect as the game playing could give practice in constructing and running aggressive scripts, which could transfer to real life behaviour.
The SLT has influenced policies to reduce aggression. For example, they have used it to put age restrictions on video games and films in the aim to reduce inappropriate viewings of aggression. However, these strategies may be insuccessful as not everyone stays by these guidlines
In spite of evidence the SLT of aggression has been criticised by those who favour a nature approach who believe for example that aggression is inherited. For example, Rhee and Waldman found that identical twins were more similar in anit-social behaviour than fracternal twins. Therefore, we cannot dismiss the role of nature in explaning aggression, which means the SLT is reductionist.
It is difficult to differentiate the role of genetics and social learning inaggression. It could be an interaction between them both, rather than one of the,. For example, Plomin et al outlined passive interactions and aggression as being an interaction between your genes and the environment that your parents create for you that suit their genes. Therefore, both genetyic and social learning alone cannot explain aggression and it might be more appropriate to consider how the two explanations interact with each other.
There is a significant amount of supporting research for the deindividuation. For example, Zimbardo used female students to give electric shocks. They found that the ones that were enveloping white costume and hoods, gave them higher levels of 'shock' than the ones in their own clothes. Therefore, TST because their identities were hidden by their costumes, there were deindividuated so were able to feel like they could act more aggressive.
The theory has led to practical applications in how police can deal with aggressive crowds. For example, modern police strategies aim to target individuals within the crowd they then feel deindividuated and less responsible for their actions. This supports the fact of being part of a crowd causes aggressive behaviour.
Deindividuation doesnt always lead to aggressive behaviour. For example, some crowds are not aggressive for example gay prides. Therefore, it might be more appropriate to consider deindividuation as an example of soft determinism as factors such as dispositions of people, the context of the purpose.
There is research to support the deprivation model. For example, Jiang and Fisher applied various explnations of aggression to 431 disiplinary reports from an American men prison and found that the situational model best explained the aggression against prison staff. TST the deprivation model of aggression is reliable as a large sample was used.
A prisoner brings in specific dispositional characteristics that make it likely that they will display aggression within prison. This explanation is known as the Importation Model and is supported by research by Harer and Steffensmeier who found individuals who exhibited aggressive behvaiour outside of prisons were more likey to exhibit eggressive behaviour inside the prison, as they had aggressive dispotions. Therefore, a prison is just where the aggression is displayed not significantly important in the cause suggesting it is due to dispositional factors.
The deprivation model doesnt take into account riots that erupt with no situational factors. For example, levels of deprivation remain fairly constant in many institutions yet violence can erupt suddenly. Therefore, it might be more appropriate to focus on levels of relative rather than absolute aggression. Also it doesnt take into account all types of aggression in prisons.
Much prison aggression has unexplained motives making it difficult to conduct research. For example, Light found that 25% of prison assults had no apparent reason and Goffman reported that prisoners often attempted to hide motives behind aggressive actions. Therefore, we cant make firm conclusions as the information is unknown making the evidence lack internal and external validity.
The theory does not take into account nature. For example, only talks about life inside prison and doesnt mention how people have been bought up and their individual differences. Therefore, the theory is reductionist as it only talks about nurture.
Research has indicated that aggressive behaviour can be imported into prisons as part of the prisoners social standing. For example, Harer and Steffensmeir who found individuals who exhibited aggressive behaviour outside of prisons were more likely to exhibit aggressive behaviour inside the prison, as they had aggressive dispotions. Therefore, instead of viewing inmates as solely influenced by one shared, common set of values, the Importation model has merit in looking at subcultures with prsions institutions which refelct their social behaviour outside of prsions.
The Importation model has very little practical applications about how to reduce aggression in institutions. Mc Corkle et al said that the theory fails to provide suggestions as how to manage aggressive prisoners or suggest policies for reducing prison violence in general. There, the model does not provide a solition where as the deprivation model does.
The model fails to ackonwledge environmental factors such as social learning and uniform. For example, the prisoners could learn about their aggressive behaviour from their peers and them imitate it, to be as successful as them in the prison environment. Therefore, it may be better to explain aggression within a prisons as an interaction between dispositional and situational factors.
Evidence from twin studies show a consistency in the genetic influence over aggression. For example, O'Connor found that Mz twins reared together and aprt were similar in their aggressive characteristics which was higher than Dz twins. TST a strong genetic compnent as Mz twins share 100% of their genes compared to 50% Dz twins suggesting aggression is nature in cause.
Supporting evidence from Brunner that shows a consistency in the genetic influence over aggression. For example, Brunner studied four generations of males in the same Dutch family who had a deficiency in the MAOA gene and found they all had a history of violence and aggression. TST there is a genetic compnent as the deficency of the MAOA gene causes aggression which can be passed down through generation so therefore due to nature.
Brunners study does not entirely spearate nature from nurture impacts on aggression. For example, in Holland young boys are actively encouraged to be aggressive and also the family may have all had a similar upbringing. TST the evidence is flawed and you cannot pinpoint the causes of aggression on either nature or nurture.
Many studies use animals in their research as they have practical advantages such as quicker breeding cycles. However, it does not take into account individual differences in humans or the effects of socialisation. Although it does not give us an insight to aggressive behaviour it cannot be generalised to humans and should be viewed with caution.
Research supports the claim that hormones have a role in aggression.
For example, Waagner tested the effect of removing testosterone by castrating male mice and found that aggressive biting attacks were reduced. He then injects tesstosterone into the mice and found the biting levels had risen again.
This suggests that nature plays a role in aggression as different levels of the hormone testosterone after aggression.
There is supporting evidence to show increased levels of testosterone causing aggressive behaviour.
For example, Daabbs investigated the relationship between testosterone, crime and prison behaviour and found that those who had committed sexual and violent crimes had the highest level of testosterone. They were also more likely to be the most confrontational prisoners.
This suggests that it is a product of nature as it is due to biological structure such as hormone have an impact an aggression levels.
The explanation for the link between hormones and aggression relies on research that is gender bias.
For example, the research focuses only on men and how aggression can be reduced in them through castration.
This suggests that it may not be generalisable to females and therefore, is not representative, meaning it is lacking ecological validity.
It is difficult to know whether testosterone causes changes in a person's dominance or if testosterone levels vary as a function of a persons position within a dominance ranking.
For example, the levels of testosterone varies with the persons dominance. Testosterone is the effect of and not the cause of aggressive behaviour.
This suggest that there is an issue of causality with the results as you cannot establish whether high levels of testosterone cause aggression or aggression increases the levels of testosterone. Also, the behaviour is often referreed to as antisocial or dominant and to be able to apply the ressults to other studies the term aggression needs to be operationalise.
Lots of studies use animals becauase they have to take away testoesterone usually by castration.
However, not only is it unethical but also may not be applicable to humans.
Therfore, results should be treated with caution as they may not be able to apply it to real life.
Infidelity and Jealousy
There is genetic cross cultures research that had been nfound to support the evolutionary theory.
For example, Buss found that human agression is not different across cultures and it is genertically determined.
This suggests that aggression in human reproductive behaviour is innate and determined by our genes and is universal meaning it is innate and supports the evolutionary theory.
Infidelity and Jealousy
There is research to support gender differences in infedelity and jealousy.
For example, Buss found that men would be more upset if their partner committed sexual infedelity whereas women were more concerned about emotional infedelity.
However, the study is lacking ecological validity as it was a hypothetical situation and the couples were forced to choose either one or the other.
Infidelity and Jealousy
There is research to support that jealousy in males is linked to cuckoldry.
For example, Gary Brase compared sexual jealousy in different cultures and found that there was a positive correlation between the level of jealousy and the fertility rate.
This suggests that the theory is reliable because the evidence is constant by saying that the males are more concerned with sexual infedelity and jealousy due to wasting their resources.
Infidelity and Jealousy
There is contradicting research for the evolutionary theory.
For example, finding from De Weerth and Kalma show that more females and verbally and physically aggreessive than men, after finding out that thier partner was having an affair.
This contradicts the evolutionary theory as it states that women are more likely to use indirect aggression than men however, here it shows that they act more physically.
Infidelity and Jealousy
The theory suggessts that we are pre-determined to act to infedelity with jealousy.
For example, this does not explain circumstances such as when men adopt or take on the role as father for another persons child, as this goes against the idea of cuckoldry.
This suggests that the theory is deterministic as it does not take into account our free will or socialisation.
There is research to support xenophobia as an explnation og group displays in competative sports.
For example, Foldes found that a core of extremist supporters led to an increases in spectator violence and xenophobic behaviour.
This suggests that the theory is reliable as it predicts that xenophobia is the motivation for group displays.
However, xenophobia alone may not explain group displays between fans at sporting events.
For example, Marsh claims that much of what passes for violent behaviour is actually highly ordered and ritualised. Being a football hooligan, enables young males to achieve a sense of personal worth and identity in the eyes of their peers.
This suggessts that group displays in sports may be part of an alternative career as opposed to aggression againsty outsiders which suggessts the theory lacks reliability.
The evolutionary theory can explain tribal warfare where casulties are few but cannot explain military conflict in recent times where therre are significant losses.
For example, Wrangham suggests that military imcompetence may be to do with an adoptive self deception of ability which increases social cohesion and may bluff the opposition but may lead to inaccurate assessment of own and opponents abilities.
This explains the high number of losses and suggests that the evolutionary theory may not be able to explain conflict in modern times making it low in ecological validity.
The power of xenophobia to produce violence has motivatd football clubs to take steps to minimise its inluence.
For example, Sheffield United have launched 'Football unites, racism divided' in an attempt to force stranger links with the local ethnic communities.
This suggests that the research into Xenophobia and sports has ecological validity and has useful real life applications.
In conclusion it fails to consider certain cultural practices and aggression.
For example, some cultures such as the Yanamamo of South America seemingly require violent behaviour to achieve social status which other such as the Kung son of Kalahari see aggression as being unforgivable.
This suggests that the theory is deterministic as it doesnt consider free will in choosing to be aggressive.