Aggression, the natural instincts of man, the hostility of each one against all and of all against each one, is an innate, independent, instinctual disposition, that constitutes a most powerful obstacle to culture (Freud, 2009). This early observation of Freud outlined what is still the ongoing argument within psychology about the nature and causes of aggression. Psychologists today are still debating on these issues with the nature vs. nurture controversy theorising on the origin of aggression and whether it is innate or if it is a learnt behaviour or both. (Geen, 2001)
Aggression can be described as one of the defining characteristics that humans have in common with other species within the animal kingdom. However, while the cause of aggression in animals is predominantly about territory, food or dominance, human beings have the ability to behave aggressively for a multiplicity of different reasons (Myers, 2005).
It should be noted however that within psychology the difference between what is classed as violence and aggression. Violence is defined as an act of aggression carried out with the intentional goal of causing extreme physical damage or harm such as injury or death to an individual such as intentionally hitting, kicking, shooting, or stabbing them. This however, differs to an act of aggression such as a child intentionally pushing another child over, which is classed as non-violent. There are only four crimes classified as violent by the US Federal Bureau of Investigation (FBI) and they are; murder, rape, assault and robbery. Therefore it can be said that whilst all violent acts are aggressive, not all aggressive acts are violent (Bushmann & Huesmann, 2010).
Aggression is generally defined within psychology as any behaviour directed towards another individual with an expectation of causing harm or with having the intentional goal of hurting others and it is seen as the most destructive force in social relations (Geen, 2001; Anderson & Bushman, 2002; Lochman, Powell, Clanton, & McElroy, 2006). It should be made distinctly clear that where harm befalls an individual through accidental means or is the by-product of helpful actions, i.e. where a fireman inflicts injury through the course of saving the individual’s life, then these actions should not be classed as aggressive, because it was not intended by the perpetrator, and the individual being harmed was not motivated to avoid the aggressive actions (Anderson & Bushman, 2002).
Aggression instinctively conjures up a perception of such acts like the use of physical force, assault with a weapon, a loud verbal retaliation or any altercation that involves conflict between two or more individuals. However, aggression can take the form of any behaviour motivated to harm another person against their will. Aggression can be inflicted in more subtle ways, such as spreading malicious rumour, infliction of damage to property or intimidation, all of which can be just as effective in causing harm to an individual (Geen, 2001). There are also differences in how aggression is displayed depending upon the gender of a person. It is widely reported that men are much more likely to display aggression through physical violence than women, who usually display aggression through non-physical or indirect methods (Cogan, Porcerelli, & Dromgoole, 2001; Hess & Hagen, 2006).
By identifying differing types of aggression, which are related to the specific intentions of the aggressor and the situation that stimulated the aggressive response, aggression can be categorised according in two distinct behaviour types. Affective Aggression, sometimes called impulsive or reactionary aggression, predominantly driven by anger and has the goal of harming the intended individual and that of Instrumental Aggression which is conceived as being premeditated and proactive with an alternative goal in mind other than that of harming the recipient individual (Geen, 2001; Anderson & Bushman, 2002).
This essay will discuss and examine several contrasting points of view from three distinct psychological perspectives, namely those of psychoanalytical, biological and social learning theory in an attempt to explain the causes for aggression within human beings.
Psychoanalytical theory originated with the work of Sigmund Freud, through his observations and clinical work with patients who were suffering from mental illness. Freud developed a theory of human behaviour, including that of aggressive behaviour that was the product of ‘unconscious’ forces operating within an individual’s mind. These behaviours that were developed in early childhood, had a profound impact on the individual’s adult behaviour, due to them being influenced by issues of conflict experienced during the differing psychosexual stages of development that occurred throughout childhood (Freud, 1920).
Freud believed that all individuals innately possess two distinct fundamental drives when they are born, that contribute to their development of both behaviour and personality. He named these drives Thanatos for aggression and Eros for pleasure, where Thanatos expresses itself in the form of aggression to others. He believed that the within each individuals psyche, the primitive forces for both life and death instincts are seeking constant expression and satisfaction, whilst constantly and continually opposing one another, with aggression being the result of this conflict (Freud, 1920; Freud, 2009).
Within the psychoanalytical model Freud (1920), viewed the aggressive instinct as part of the Id, a part of the psyche that stimulates behaviour, while the ego and superego oppose or represses the aggressive impulses within. The conflict between these different parts of the psyche results in tension within the individual, who then use defence mechanisms to block any conscious awareness of this conflict. Although aggression is regarded as a basic id-based impulse, within well adjusted individuals who mature through a normal childhood this impulse is repressed. However, if this impulse is not controlled or overly repressed then this can lead to aggression ‘leaking’ out. Freud referred to this as ‘displaced aggression’ (Englander, 2007).
Lorenz (1966) posited a belief that these uncontrolled impulses could potential build up within the individual, like a form of hydraulic pressure inside a closed environment. If this suppressed build up of aggressive urges was not released in some form, then the result would be an inevitable act of aggression towards others. Although there has been little empirical support for Lorenz’s hydraulic model of aggression, the theory that aggression is due to the build up of an internal drive or tension that can be released through sports or other physical activities, has had a profound influence on clinical psychology today in the form of cathartic therapies (Bushmann & Huesmann, 2010).
Anna Freud (1970) also accentuated that any damage to the parent-infant bonding process can be directly related to the causes of aggressive behaviour. She believed that emotional attachments experienced within early childhood help to neutralise aggressive impulses in later life. Bowlby’s (1944) study on a group of juvenile delinquents supports this argument as he found that a large percentage (39%) of the participants had experienced significant maternal deprivation in comparison to only 5% of the non-juvenile delinquent participants. The outcome of this study led Bowlby to propose that the ability to form meaningful relationships within adulthood was reliant on a close and continuous relationship with the mother within childhood (Bowlby, 1958)
Social learning theory (SLT), which emerged in the 1960s primarily from the work of Albert Bandura and his associates, differed in its opinion of the origin and causes of aggressive traits to those within the psychoanalytical field (Geen, 2001). SLT does however appear to agree with the psychodynamic theory that childhood experiences play an important role in the behavioural development of an individual through the experiences encountered in (Bandura, 1977).
Earlier behavioural research had showed children could be taught to behave aggressively through conditioning by both positive and negative reinforcement techniques (Cowan & Walters, 1963; Patterson, Littman, & Bricker, 1967), and that children could even learn how to discriminate between the different situations of when aggression was rewarded and when it was not. However, Bandura believed that direct reinforcement could not account for all types of learning and so by adding a social aspect to the learning process, Bandura devised and conducted several observational learning experiments to show that people can learn how to behave aggressively by observing and imitating others (Bushmann & Huesmann, 2010).
In the Bandura, Ross, and Ross, (1961) infamous Bobo doll study, two groups of 36 individual boys and girls watched a video clip of an adult behaving either aggressively or non-aggressively in a room filled with toys. In the aggressive model it showed the adult behaving both physically and verbally aggressive towards the Bobo doll by punching and shouting at it. After watching the video each child was taken to another room where there was a variety of toys including a Bobo doll. Observations by the researchers found that children who had been exposed to the aggressive actions reproduced a great deal more verbal and physical aggression than those in the non-aggressive and control conditions (Bandura, Ross, & Ross, 1961).
The results of this study confirmed Bandura’s claims and argued that the acquisition of behaviours can be learnt through watching others. Further research has shown that children, who model aggressive behaviours, could account for why there are correlations which indicate why male abusers often come from families in which the mother was abused or where individuals who have frequently observed other forms of aggressive acts, through extensive exposure to media violence through the playing of computer games or watching graphically violent films, display aggressive behaviour in later life (Lundberg, 1990; Anderson & Dill, 2000).
Social learning theory has shown that people can learn aggressive behaviour through the observation of another person’s actions. However, it has been found that the behaviour is only exhibited if the behaviour is rewarded with a favourable outcome (Zimbardo, 1969). In Bandura, Ross, and Ross, (1961) study, for example, when children saw the role model being punished for being aggressive towards the Bobo doll, no replication of the aggressive behaviour was seen when they were given the opportunity to play with the doll. They were however able to copy the behaviour when specifically asked to do so. This shows ability for individuals to learn behaviour but to make a clear choice not exhibit it, due to social constraints or fear of punishment (Bandura, 1977).
However, Festinger, Pepitone and Newcomb (1952) believed that under certain conditions individuals can become deindividuated, which refers to the phenomenon of a person losing their inhibitions because they are no longer identifiable due to them merging with that of a larger group. Deindividuation occurs when individuals become part of a large group or a crowd and they have the opportunity to exhibit the observed behaviour of others, anonymously, without the fear of being punished. This theory has been used to explain why people who are usually well-behaved can become aggressive and violent during, for example the recent city riots that occurred throughout the UK in 2012 (Guardian News and Media Ltd, 2013).
Within the study of psychology today to set ‘nature’ against ‘nurture’ when discussing aggression in humans is to create a false dichotomy. Almost every psychologist who investigates the problem would be in agreement that both are involved and that any dissimilarity between viewpoints involves the relative emphasis placed on them both. Geen (2001) suggest that both learning and heredity/biological factors are best understood as background variables that create a level of potential for aggression.
Aggressive behaviour is a response to certain condition and it must be acknowledged that even when an individual is disposed to aggress as a result of that imposed condition, a specific situation must elicit the act of aggression. This will invariably involve criteria from both the nature of the condition and the level of potential for aggression set by these background variables. As with the psychoanalytic perspective, biological psychologists believe that certain people are born with a stronger disposition to be more aggressive when provoked than those lacking such dispositions (Geen, 2001).
The field of biopsychology or physiological psychology studies physiology and biological processes such as the immune system, nervous system and genetics. Through the use of modern technology it is now possible to study the brain and nervous system using such tools as PET and fMRI scanners to look at how certain drugs, hormones, disease and brain damage can impact behaviour and cognitive functioning (Myers, 2005).
A number of different biological characteristics including genetic influences have been identified in individuals who appear to be more or less aggressive than others. Evidence for this has been supported through studies of monozygotic and dizygotic twins, where it has been found through self reported measures, that if one twin exhibits aggressive behaviour, the other often does so as well. This showed a much higher positive correlation amongst the monozygotic twins (Geen, 2001).
A study by McDermott, Tingley, Cowden, Frazzetto, and Johnson (2009) looked at the differences in the gene MAO-A which produces Monoamine Oxidase (MAO). This has been called the warrior gene and has been associated with increased aggressiveness. The MAO-A gene, is involved in the breakdown of the neurotransmitters serotonin, dopamine and nor epinephrine which are recognised as being part of the human fight or flight response. Individuals who were found to produce lower levels of MAO showed significantly higher aggressive behaviour when faced with provocation (McDermott, Tingley, Cowden, Frazzetto, & Johnson, 2009).
Other bio-psychologists have studied the production of aggressive behaviour as a result of exposure to the nervous system by drugs, such as alcohol or hormones such as cholesterol and testosterone (Bushman & Cooper, 1990; Ramirez, 2003; Archer, 2006; Hillbrand & Spitz, 1999). Alcohol was found to cause aggression by anesthetizing the centre of the brain that normally prevents an aggressive response to provocation and by causing changes to the cognitive, physiological, and emotional influences of the individual, resulting in a higher probability of aggressive behaviour (Bushman & Cooper, 1990).
Archer (2006) noted that a number of studies have examined the relationship between aggression and Androgens, such as testosterone, not only adult men, but in women and in children too. Studies that involved offenders, reported higher testosterone levels amongst those individuals who were classified as aggressive when compared to the non-violent offenders. Again this was seen to be valid for female offenders (Archer, 2006). Hillbrand and Spitz (1999) identified many studies that have identified a link between cholesterol and aggressive behaviour. In far back as 1925 Brice (1935, cited Hillbrand & Spitz, 1999, pp .359) reported that patients with schizophrenia whose total serum cholesterol (TC) levels were high, were far more emotional expressive.
Another area of the brain that has been linked to aggression is the frontal lobes. It is acknowledged that they participate in many activities that require decision making. Cognitive processes that include social behaviour, problem solving, impulse control, motor functions and personality are all functions that take place in this area of the brain. Evidence to support that aggression is related to frontal lobe function was first seen in the case of Phineas Gage, following an accident in 1848, where an iron rod was propelled through his skull causing severe damage to his frontal lobes. Although the accident did not kill him, it was observed that a dramatic change to his personality followed, with him becoming more aggressive, obstinate, impatient and impulsive (Seguin, 2009).
It can be argued that the biological approach offers a more in depth and comprehensive view of aggression than that of the psychoanalytical perspective. Yet as have shown within psychology today there is a universally accepted that there is no simple nature against nurture argument when discussing aggression in humans Both innate and social learning are important factors and can be seen that people neither driven completely by their innate urges nor are they helplessly vulnerable to the affect of environmental influences.
With the occurrence of spectacular violent events, like mass murders in schools, it is all too easy to confound these separate contributors by blaming social conditions, individual differences or even the mental instability of the aggressors. There is no disputing that all of these and other factors may be involved. In order to reach an accurate analysis such an event requires that each factor must be seen in terms of its proper function, not as an alternative ’cause’ that explains everything (Geen, 2001).
Even when a person is disposed to aggress and has the capability of behaving aggressively, it still requires a specific situation in order for the act to commence. Thus, in order to fully understand the complicated nature of aggression, further research is required in all areas before it is possible to accurately state with any conclusion what the origins and causes are for aggression in humans.