There are two main schools of thought to explain the root cause of aggressive behaviour in human beings. Theories can be roughly divided into four types, biological theories of aggressive behaviour, psychological, environmental and sociological based theories. (Hollin, 1991) If you group the ‘internal’ theory types, biological and psychological, then pair up the ‘external’ based theories, environmental and sociological – that brings the basis for the theories down to two, social and biological. (AIC, 2002) [Use of internal and external here, is not to be confused with internal/external locus of control]
As there are many theories about the cause and root of human aggression, there are also many ideas about what constitutes aggressive behaviour. Does aggression mean, hitting people, taking drugs, swearing, non conformity? In 1977 Baron described aggressive behaviour as; “The intentional infliction of some type of harm, on others.” (Vaughan and Hogg, 2002) Thus hitting, swearing – if intended to inflict pain (as in abusive language) and even non-conformity – if used as a way to deliberately hurt another person – can all be viewed as forms of aggressive behaviour. However these definitions are often argued and not often agreed upon. Determining aggression itself is not easy and many acts thought as aggressive by one person, are not seen as aggressive by other people. (Dryden and Prower, 1989: 130; Vaughan and Hogg, 2002)
Many people have tried to distinguish between aggression and assertion, Hollandsworth, 1977; Hedlund and Lindquist, 1984, for example. (Dryden and Prower, 1989: 139) The difficulty seems to lie in the intent of the perpetrator. Graffiti, for example, are often thought of as an aggressive response to frustration or anger, especially if a young person works the graffito. (Vaughan and Hogg, 2002; Goldsmith et al, 2003: 96) Certainly, it could be said that the graffiti artists are doing damage with the intent to harm others but property damage is not always the motive behind the act. Graffiti are now thought of as an act of assertion, a way to determine and signal territory, a way to leave a mark and show/say, “look I’m here”. (Bandaranaike, 2001) As difficult as it is to determine which behaviour has an aggressive base and which doesn’t, it appears to be just as complex to explain the origins of aggressive behaviour.
Some of the first detailed explanations of aggressive behaviour concluded that an aggressive reaction to a situation arose from instinct. The theory that aggression is both an instinct and a fighting response, was explored and developed by Freud in some detail. Freud’s psychodynamic theory determined that a human’s subconscious, the part of the personality Freud called the id, contained the aggressive instincts. The id operates on an instant gratification level, regardless of others and consequences. (Goldsmith, Israel and Daly, 2003: 70) Freud suggested that not only was aggression a natural, instinctive response but also that tension in the body built up and needed to be vented and that this was also a naturally occurring urge. (Vaughan and Hogg, 2002)
Whilst Freud suggested that aggressive behaviour in humans was innate, later theorists deduced that human behaviour was equally instinctive and rational. Lorenz developed the theory that whilst instinct was at play in aggression, reaction to outside stimulus played an important role. He also proposed that aggression had value in assisting humans to survive, in that the most adapted/adaptable humans would perpetuate. (Vaughan and Hogg, 2002; Raine, 1993)
Another group of theorists, in the developmental and social learning schools, developed the idea that aggression was not an instinct but a learned behaviour. Aggression can be learnt, just like anything else. These theories are often based on the work of Albert Bandura. Bandura developed his theory of social cognitive learning as having three main principles:
a) humans learn by observing the behaviour of others
b) we imitate behaviour and keep imitating if the behaviour is reinforced
c) both imitation and observational learning rely on operant conditioning principles even though sometimes the reinforcement has to be imagined and is not actual.
(McInerny and McInerny, 1994)
B F Skinner’s theory of operant conditioning played a role in the development of Bandura’s theory. Skinner’s work demonstrated the theory that if a particular type of behaviour was rewarded, that behaviour would continue. If the reward stopped, the behaviour stopped. Bandura then enhanced this theory and added that humans can also learn indirectly by observing. We can watch what happens to other people and see the reward/consequences they receive, we do not have to perform the behaviour and receive the reward or punishment ourselves. (Goldsmith et al, 2003: 74; Hollin, 1991)
Social cognitive learning starts when we are very young, as we imitate language and movement etc. However, humans are capable of learning aggressive behaviour at a young age too. Bandura showed that a child, aged three to five years, could learn aggressive behaviour by watching someone else demonstrate that type of behaviour. The child did not have to stand and imitate the behaviour, rather they could watch what an adult did, then when faced with a similar set of circumstances, could manifest the behaviour for themselves. (Bee, 1975; Vaughan and Hogg, 2002; Goldsmith et al, 2003: 74; Hollin, 1991)
Before Bandura and Freud developed their explanations for aggressive behaviour Cesare Lombroso, an Italian doctor of the 1870’s, determined that some prisoners were genetically different to the general population – their biology made them aggressive and/or born to be criminals. (Hollin, 1982; Goldsmith et al, 2003: 65) During the 1940’s, it was shown that a number of criminals, who exhibited violent behaviour, had a higher incidence of epilepsy. (Hollin, 1991) Since then, Gunn and Felton (1969), Mark and Irvin (1970) and Loews (1976) have corroborated that finding. Were the subjects used in this research born with epilepsy and did the epilepsy bring a genetic predisposition to aggressive behaviour or did the behaviour come after the change in health status? (AIC, 2002)
Since then, there have been many genome-based studies with twin and adoption studies forming a large part of the research. In 1988 Mednick, after twin and adoption research, concluded that violent behaviour was not inherited. (AIC, 2002) Gene and genetic transfer studies became unpopular and often refuted but in the last 15 years or so, study into the chemistry of the brain has resurfaced. Researchers have again been trying to determine if genes or chemistry decides the propensity for an individual’s aggressive behaviour. (AIC, 2002)
There is much argument about what genes actually do determine. If aggressive behaviour, as all behaviour, is determined by the brain, and the brain’s development is determined by genes, then all behaviour must be genetically encoded. (BMA, 1995; Lawson and Heaton, 1999) Genes might establish propensity and preferences for particular behaviour but environment and illness have their effects. Researchers, such as Boorse (1975, 1976) have concluded that mental illness, whilst not a physical disease of the brain, change the brains functioning. If the function of the brain is interfered with, then personality and responsibility could undergo change, too. (Blackburn, 1993)
Apart from the role of genes and mental illness, researchers are working on hormonal changes, the role of the central nervous system, intelligence, diet and Attention Deficit Disorder and their effects on the brain and behaviour. (AIC, 2002; Hollin, 1992)
Each of these types of theory about aggressive behaviour has its detractors and supporters. Gene based biological theories (people are born criminals) became unpopular in the last century but have reappeared with advances in brain imaging – though now seen as neurological studies. (AIC, 2002; Goldsmith et al, 2003: 68)
Freud’s theory has been expanded on by Jung, Erikson, Adler and Aichorn, amongst others but has now become of lesser importance in the explanation for aggressive or criminal behaviour. (Hollin, 1991) Bandura’s theory and its development by others, is still used to detail aggressive behaviour and to develop learning/teaching strategies to help aggressive and violent people change their behaviour. (Howells, 1989; Goldsmith et al, 2003: 75)
The two biological theories, the role of genes and Freud’s theory, can both be traced back to Darwin’s Theory of Evolution. Freud’s psychodynamic theory and Bandura’s social cognitive theory are mostly concerned with how humans seek pleasure and avoid pain or punishment by the way they set up their response and thought processes. Whilst parts of each of these two theories can apply to later life, mostly they are concerned with developing a style of response before adulthood, determined by childhood. (Andrews and Bonta, 1994)
Freud’s theory casts everyone as a potentially and naturally aggressive, Lombroso’s work and work of other gene researchers, states that some people are born to be aggressive but Bandura says we learn to be aggressive. (Andrews and Bonta, 1994; Hollin, 1991)
As aggression appears to be a complex interplay caused by a multitude of factors, there will continue to be research into causes, prevention and avoidance. The research will throw up new theories and advances in research techniques and medical imaging will support or dispute the validity of the presented argument. Either way, criminologists, social workers, psychologists, government agencies and justice workers will all be interested in the findings of future research. (AIC, 2002; Goldsmith et al; 78)
REFERENCES
Australian Institute of Criminology – AIC (2002), Explaining Violence, in Directions for Australia – Part 2: biological factors. Available from, www.aic.gov.au/publications/vda/vda-sec08.html
Andrews, D. and Bonta, J. (1994), Psychology of Criminal Conduct. Cincinnati, Ohio, USA: Anderson Publishing
Bandaranaike, S. (2001), Graffiti: A Culture of Aggression or Assertion? Paper, The Character, Impact and Prevention of Crime in Regional Australia Conference. Townsville, Queensland. Available from, www.aic.gov.au/conferences/regional/
Bee, H. (1975), The Developing Child. New York, USA: Harper and Row
Blackburn, R. (1993), The Psychology of Criminal Conduct. Chichester, England: Wiley
British Medical Association – BMA (1995), A Mind to Crime. British Medical Journal, 311, 956
Chappell, D. & Wilson, P. eds (2000), Crime and the Criminal Justice System in Australia: 2000 and Beyond. Sydney, Australia: Butterworths
Dryden, W. & Prower, P. eds (1989), Development in Cognitive Psychotherapy. London, England: Sage
Goldsmith, A., Israel, M. & Daly, K. (2003), Crime and Justice: An Australian Textbook in Criminology. Pyrmont, NSW: Lawbook Company
Hollin, C.R. (1991), Psychology and Crime. London, England: Routledge
Lawson, T. & Heaton, T. (1999), Crime and Deviance. Hampshire, England: MacMillan Press Ltd
McInerny, D. and McInerny, V. (1994), Educational Psychology. Sydney, Australia: Prentice Hall
Raine, A. (1993), The Psychopathology of Crime: Criminal Behaviour as a Clinical Disorder. San Diego, USA: Academic Press
