Motivation and emotion/Book/2010/Aggression in the workplace
Aggression in the Workplace
[edit source]
Overview
[edit | edit source]This chapter is divided into two parts. The first part of the chapter will discuss the definition of aggression, the biological factors and associated theories. The second part of the chapter will discuss occupational violence and aggression with an emphasis on the identification of violent and aggressive behaviour. This is followed by aggression and violence prevention methods.
Aggression
[edit | edit source]Definition
[edit | edit source]Aggression is a verbal or physical behaviour aimed at harming another person or living being (Anderson & Bushman, 2002). Additionally, the perpetrator must believe that the behaviour will harm the target, and that the target is motivated to avoid the behaviour (Baron & Richardson, 1994; Berkowitz, 1993). Aggression may appear appropriate and self-protective, even constructive, as in a healthy self-assertiveness, or inappropriate and destructive. Aggression may be directed outward, against others, or inward, against the self, leading to self-destructive or suicidal actions. Aggression may be driven by emotional arousal, often some form of frustration, or it may be instrumental, when it is used to secure a reward (Anderson & Bushman).
The roots of aggression
[edit | edit source]The universality of aggression and the individual differences seen in aggressive behaviour have lead to considerable controversy about its origins. Some theories maintain that the roots of aggression lie in biology and evolution, others look to the environment and social learning. In this section of the chapter, we explore instinctual, evolutionary, cognitive-neoassociation and cognitive social approaches. The biopsycholoical processes that underlie aggressive behaviour are also examined.
An instinctual perspective
[edit | edit source]Theorists supporting this perspective argue that aggression and aggressive drives are instinctual. For example, Sigmund Freud postulated that all humans possess an aggressive drive from birth, which, together with the sexual drive, contributes to personality development and found expression in behaviour. Konrad Lorenz also suggested that aggression is instinctual. He contended that the suppression of aggressive instincts, common among human societies, allows instincts to build up over time, occasionally to the point where they are released during instances of explosive violence.
Interestingly, in every human society ever observed, socialisation to control aggressive impulses is one of the most basis tasks of parenting (Whiting & Child, 1953). Infants and toddlers bite, scratch and kick when they do not get what they want and as children get older, they show less overt aggression (Hartup, 1998). This change in behaviour suggests that aggression relates to frustration, however, societies have to teach children to inhibit aggression, rather than that aggression is primarily learned (as discussed further in the chapter).
An evolutionary perspective
[edit | edit source]The theorists who viewed aggression as instinctual did not address the evolutionary adaptations of aggression. Aggression, including killing members of one’s own species, occurs in all animals. From an evolutionary standpoint, the capacity for aggression evolved because of its value for survival and reproduction (Lore & Schultz, 1993). Males typically attack other males to obtain access to females and to keep or takeover territory. Contemporary evolutionary psychologists believe that humans, like other animals, have evolved aggressive mechanisms that can be activated when circumstances threaten their survival, reproduction, the reproductive success of their offspring or the survival of their mating partner.
Neural systems
[edit | edit source]The neural systems that control aggression are hierarchically organised. Neurons in the hypothalamus are part of circuits regulated by the cortex and the amygdala and hypothalamus are involved in emotional reactions and drive states. When Egger and Flynn (1963) and Robinson, Alexander and Brown (1969) electrically stimulated regions of the lateral hypothalamus of cats and rhesus monkeys, the animals immediately attacked. According to King (1961), similar results occured in humans when electrodes were implanted in the amygdala. Creating legions in parts of the midbrain can also eliminate an animal’s ability to respond with species-typical aggressive motor movements, suggesting a substantial role for midbrain structures in aggression (Carlson, 1999). Other factors, including learning difficulties, brain damage, brain abnormalities, such as temporal lobe epilepsy, and social factors such as crowding and poverty have been suggested to certain cases of aggressive behaviour (Anderson & Bushman, 2002).
Hormones
[edit | edit source]Studies being performed in endocrinology are being undertaken to determine whether hormonal imbalances have an impact on behaviour as hormones play a substantial role in the tendency to behave aggressively (Anderson & Bushman, 2002). In all species, males are more aggressive than females, and these sex differences appear to be linked to action of the hormone testosterone both before birth and during development (Archer & Lloyd, 1985). Throughout the world, men fight more often that women and are more likely to get arrested for violent crimes (Gianakos, 2002). Moreover, young adult men, who have the highest testosterone levels, also have the highest rate of aggressive behaviours and violent crimes (Gianakos, 2002). Women commit violent acts also, but they are usually more minor attacks (Gianakos, 2002.).
Men convicted of violent crimes also tend to have higher testosterone levels than non-violent offenders (Archer, 1991). However the problem with drawing conclusions about the relationship between testosterone and aggression is that the two constructs represent something of a chicken–egg problem. Although testosterone may increase aggression, behaving aggressively can also increase testosterone (Archer, Birrring & Wu, 1998).
Testosterone is not the only hormone that has been linked to aggression. A number of other studies in humans and other animals associate aggression with low serotonin levels (Cleare & Bond, 1997; Suomi, 2000). Additionally, researchers have found that intentionally lowering serotonin levels decreases tolerance for frustration and increases the likelihood of aggression.
Testosterone is linked to social dominance and thus lead to aggression in the service of maintaining status within a social hierarchy (Olweus, 1988). Serotonin is linked to impulsivity (acting without thinking) and thus leads to unprovoked and socially inappropriate forms of aggression (Higley, Mehlman, Taub, Higley, Suomi, Linnoila, & Vickers, 1992).
Summary
[edit | edit source]Instinctual theorists view aggression as an inborn potential usually activated by frustration. Evolutionary theorists similarly view aggression as inborn human potential that gets activated under conditions that affect reproductive success, such as competing for territory or mates and protecting oneself and related others. The neural control of aggression is hierarchically organised, with the amygdala, hypothalamus and cortex (particularly the frontal lobes) playing prominent roles. Aggression is also partially controlled by hormones, particularly testosterone and serotonin.
Test Your Knowledge 1PLEASE NOTE: THERE ARE 20 QUIZ QUESTIONS IN THIS CHAPTER. IF YOU WOULD LIKE TO COMPLETE ALL 20 QUESTIONS, DO NOT PRESS SUBMIT UNTIL YOU HAVE COMPLETED 'TEST YOUR KNOWLEDGE 4'.
|
Cognitive Perspectives
[edit | edit source]Cognitive neoassociation theory
[edit | edit source]Dollard, Doob, Miller, Mowrer, & Sears (1939) proposed one of the first theories of aggression, the frustration-aggression hypothesis. This theory states that when people are frustrated in achieving a goal, they become aggressive. A reformulated frustration-aggression hypothesis developed by Berkowitz (1989) suggests that aversive events such as frustrations, provocations, loud noises, uncomfortable temperatures and unpleasant odours produce an unpleasant negative emotion (negative affect). Negative affect produced by unpleasant experiences automatically stimulates various thoughts, memories, expressive motor reactions and physiological responses associated with both fight and flight tendencies. The fight associations give rise to feelings of anger, whereas the flight associations give rise to feelings of fear. Furthermore, cognitive neoassociation theory assumes that cues present during an aversive event become associated with the event and with the cognitive and emotional responses triggered by the event (Berkowitz, 1989). Berkowitz (1989) contended that all animals learn the most effective response to an aversive occurrence (one where the expected reward is denied), whether it be fight or flight.
A cognitive-social perspective
[edit | edit source]The capacity for aggression appears to be innate but the activation and inhibition of aggression may very much depend on culture and learning. According to social learning theorists (Bandura, 1977; Mischel, 1973), people acquire aggressive responses the same way they acquire other complex forms of social behaviour, either by direct experience or by observing others. Social learning theory explains the acquisition of aggressive behaviours via observational learning processes. The theory also provides a useful set of concepts for understanding and describing the beliefs and expectations that guide social behaviour (Bandura, 1977; Mischel, 1973). Albert Bandura performed studies that indicated that aggression is a learned behaviour. Using children in his studies, he demonstrated that by watching another person act aggressively and obtain desirable rewards or by learning through personal experience that such behaviour yields rewards, aggression can be learned.
The script theory
[edit | edit source]Huesmann (1986) proposed that children who observe violent behaviour in the media learn aggressive scripts. According to Huesmann (1986), scripts define situations and define behaviour. The person first selects a script that fits the situation and they then assume a role in the script. Once a script has been learned, the person may retrieve it at a later time and use it as a guide for behaviour.
The general aggression model
[edit | edit source]The general aggression model (GAM) was created to give meaning to the myriads of theories that currently exist to explain aggression. Incorporating what researchers viewed as the best of each of the earlier theories of aggression, the GAM explains how a person and situation input variables influence aggression through the cognitions, emotions and arousal they generate (Anderson & Bushman, 2002). In short, person variables, such as personality traits, genetics, attitudes, values and scripts interact with situational variables, including aggressive cues, provocation and aversive situations, to produce particular cognitions and feelings. For example, if a highly aggressive individual is placed in a situation where guns are present, the guns will activate aggressive scripts that will subsequently drive aggressive behaviour (Anderson & Bushman, 2002).
Aggression and gender
[edit | edit source]Gender differences in aggression appear consistent across cultures. In most societies, males commit over 90% of criminal and aggressive acts. Gender differences also exist in the types of aggression most likely to be perpetrated by men and women. Whereas men engage in more direct aggression, women perpetrate aggression more indirectly. For example, males are more likely bully their peers through verbal or physical aggression. Females on the other hand, are more likely to socially exclude or ostracise their target.
In light of the fact that males possess higher levels of testosterone and report higher levels of aggression, in the workplace, this is yet to be proven. Gianakos (2002) examined the issue of anger in the workplace and found that gender does not relate to anger in the workplace. Further research must be undertaken in this area.
Summary
[edit | edit source]According to cognitive-social theories, the roots of aggressive behaviour lie in social rewards, punishments and cognitive processes such as observational learning. The general aggression model states that person variables interact with situational inputs to determine aggressive output. The capacity for aggression appears to be innate, but the activation and inhibition of aggression also depends on culture, scripts and learning. Research suggests that males are more likely to exhibit direct forms of aggressive behaviour, whereas females are more likely to exhibit indirect forms of aggressive behaviour.
Test Your Knowledge 2[edit | edit source]
|
Occupational violence and aggression
[edit | edit source]Occupational violence and aggression is the attempted or actual exercise by a person of any force to cause injury to a worker, including any threatening statement or behaviour which gives a worker reasonable cause to believe he or she is at risk (Mayhew, 2000). Occupational violence and aggression includes any incidents by which an employee is abused, threatened or assaulted in circumstances arising out of, or during the course of, their employment (Mayhew, 2000). Occupational violence and aggression has received increasing attention since the 1980s as high profile reports of violence and aggression in the workplace have found their way into the media. Additional reasoning for its increased growth as a prominent social issue is due to its significant legal, economic, and emotional ramifications for employers and employees. Occupational aggression can result in fatality, physical injury or psychological harm (Mayhew, 2000).
Violent and aggressive behaviour in the workplace includes: Verbal abuse, threats, physical violence, behaviours that create an environment of fear, stalking, bullying amongst workers or between managers and workers, and behaviours that lead to stress or avoidance behaviour in the recipient. Other violence risk factors include: management toleration of bullying, job insecurity, workers facing unemployment with little chance of re- employment, a loss of self-esteem and stability among workers, and disciplinary suspensions (Mullen, 1997; Witkowski, 1995). However, the usual basis for violence or aggression in the workplace is the consequence of a disgruntled employee who threatens a co-worker or supervisor for what is perceived as unfair treatment (LeBlanc, & Kelloway, 2002). The advancement of female workers may further contribute to the resentment felt by some males who perceive they have been passed over unfairly (Mullen, 1997).
Verbal abuse and threats are the most common forms of internal violence and aggression (Gianakos, 2002). While internal violence and aggression is usually face-to-face, inappropriate behaviour can be communicated via email, telephone, or through exclusion of the recipient. The perpetrators of aggression and violence act as they do because of envy, fear of their own inadequacy, experience of childhood bullying, provocation, and an inability to manage their own aggression (Gates, 1995). The recipients of workplace violence and aggression are commonly more attractive, confident, successful, qualified and popular than the perpetrators. The recipients may also be different in some way, for example ethnicity or age (Gaymer, 1999). While some bullying activities are obvious, others are subtle and covert. It is often reported that inappropriate behaviour develops slowly over time and perpetrators may not even be aware of the impact of their conduct (Mayhew, 2000).
Can Aggression be Acceptable in the Workplace? . Source: Mayhew, C. 2000. Preventing violence within organisations: A practical Handbook. Australian Institute of Criminology, 29, p.5. |
Incidence of occupational violence and aggression
[edit | edit source]Johnson and Indvik (2000) suggested that one out of four employees are angry at work and employees aged 18 to 34 years are more than four times likely to report feeling angry compared to employees aged 50 years and over. Moreover, 35 per cent of Australians had been on the receiving end of verbal abuse from a co-worker, and 31 per cent from a supervisor (Mayhew, 2000). According to Cortina, Magley, Williams and Langhout (2001) 71 percent of workers have been subjected to negative behaviour in the workplace. Much of the research in this area examined direct aggression with a clear intent to physically harm (Campion, Medsker, & Higgs, 1993; Mowday, Steers, & Porter, 1979).
Numerous studies have suggested that violence rarely “comes out of the blue”, but is commonly preceded by behaviour that indicates a potential for violence (Speer, 1997). The best predictor of future aggression remains past aggressive behaviour. Supervisors or employees with a history of assaults, or who have exhibited belligerent, intimidating or threatening behaviours, are higher risk (Chappell & Di Martino, 1998; Cherry & Upston, 1997). White males in the age range 30 to 50 years, who are married with families, and who have been employed with the organisation for some time may be more common perpetrators of violence (Capozzoli & McVey 1996; Dale, Tobin, & Wilson, 1997; Heskett, 1996. Recent or imminent job loss can be another high-risk factor (Myers, 1996). However, relying on profiles is a dangerous practice, as violent and aggressive behaviours have been committed by a range of people under a variety of circumstances.
Summary
[edit | edit source]Occupational violence and aggression is the attempted or actual exercise by a person of any force to cause injury to a worker, including any threatening statement or behaviour which gives a worker reasonable cause to believe he or she is at risk. Violent and aggressive behaviour includes verbal abuse, threats, physical violence, stalking, bullying and behaviours that lead to stress or avoidance behaviour. The best predictor of future aggression remains past aggressive behaviour. {{Hide in print|
Test Your Knowledge 3[edit | edit source]
|
Consequences of occupational violence and aggression
[edit | edit source]Any form of violence can have serious effects on the workforce, employer, and recipient, and negative productivity and profitability impacts can even threaten organisational survival. Moreover, it has been argued that aggression experienced in the workplace has more negative consequences on the individual than aggression experienced in other settings (Bolger, DeLongis, Kessler, & Schilling, 1989). The potential consequences of aggression and violence include high levels of anxiety, depression (Bjorkqvist, Osterman and Hjelt-Back, 1994), stress-related illness, higher levels of absenteeism and turnover amongst recipients; diminished productivity, lower job satisfaction and employee involvement (Reynolds, 1994; Wynne, Clarkin, Cox, & Griffiths). Morrison (2008) investigated the link between perceptions of negative workplace relationships and organisational outcomes. The results indicated that those employees who experienced at least one negative relationship at work were significantly less satisfied with their employment, reported less organisational commitment, were part of less cohesive workgroups and were more likely to seek other employment. Overall, experiencing violence and aggression in the workplace affects the quality of people’s private lives and their overall satisfaction with their employment (Burke & Greenglass, 1987).
If a recipient of violence and aggression is engaged in insecure employment, they may be less willing to report lower-level violence because of job loss fears. The personal emotional trauma and costs from perceived or real threats may be "considerable and cumulate" (Mayhew, 2000). Depression amongst recipients is likely to be significantly exacerbated by non-supportive colleagues who wish to avoid involvement and protect their own jobs, and so they ignore the pain experienced by recipients, exclude them, and may even “blame the victim” (Mayhew, 2000).
Preventing occupational violence and aggression
[edit | edit source]The manager and organisational culture
[edit | edit source]Management style and organisational culture can influence the occurrence of occupational violence and aggression, as managers can have a significant impact on an organisation’s culture (Hambrick & Mason, 1984). However, it is often difficult to make a clear distinction between “bad management” that contributes to a violent culture and inappropriately coercive management behaviour (Mayhew, 2000). Irrespective of intent, primary legal responsibility for prevention of occupational violence rests with the employer and management within the organisation (Strachan, French, & Burgess). If violent or aggressive behaviours have been ignored, tolerated or worse yet, allowed to take place, the perpetrator may believe the behaviour to be acceptable and normal. Support for the recipient and strong enforcement of behavioural change and behaviour monitoring should be used in cases such as these. Management should also take precautions to ensure that recipients are not in receipt of further victimisation through effective implementation of policies and strategies. Moreover, managers that foster teamwork and improve employer/employee communication will help reduce the potential for occupational violence and aggression (Mayhew, 2000).
Training
[edit | edit source]Training for workplace violence and aggression prevention should be included in induction and re-training courses as well as for “at risk” staff (Mayhew, 2000). Topics covered in this type of training should include the policy and strategies in place, risk identification, risk assessment, and risk control procedures, warning signs of potential violence and aggression and appropriate responses; security provisions and emergency plans; interpersonal relations and skills for diffusing aggression; and incident reporting procedures (Mayhew). Employees must also be taught that the failure to report one-off incidents may put others at risk at a later stage.
Occupational Violence and Aggression: The Volcano Metaphor[edit | edit source]By David Van Fleet and Ella Van Fleet. An easy way to conceptualise the process by which seemingly simple events build toward violence is to use the metaphor of a volcano. A volcano sits dormant until events occur that lead to its eruption. Many individuals appear to be relatively unruffled by other individuals or events until gradually stress and anger build up – often from multiple sources, leading to dysfunctional behaviour and eventually violence. Just as volcanoes tend to rumble, tremble and even spew to give warning signs of impending threat, so do individuals who are about to “go postal”. However, the slowness or swiftness with which an individual moves through the sequential phases can vary greatly, from many months to only a few hours. Thus, predicting when and how violently either will erupt is still possible. However, successful intervention is more likely when we understand how the Violence Volcano operates.
Source: Van Fleet, D.D. & Van Fleet, E.W. (2007). Preventing workplace violence: the violence volcano metaphor. Journal of Applied Management and Entrepreneurship, 12, 17-30. |
Pre-employment tools
[edit | edit source]It is generally easier to prevent violence arising in the first place than it is to intervene after inappropriate behaviours have commenced. Pre-employment processes can include careful screening of potential employees to reduce the likelihood of hiring those who have previously engaged in violence (Mayhew, 2000). For example, careful reading of applications, checking of work history for rapid turnover of jobs, scrutiny of references, and clarification of reasons for periods away from work can reduce the risk of inappropriate hiring (Randall, 1997).
Summary
[edit | edit source]Any form of violence can have serious effects on the workforce, employer, and recipient. Management style and organisational culture can influence the occurrence of occupational violence and aggression, as managers can have a significant impact on an organisation’s culture. Primary legal responsibility for prevention of occupational violence rests with the employer and management within the organisation. Training for workplace violence and aggression prevention should be provided to all staff. The volcano metaphor is an effective way to identify potential and actual aggressive behaviour.
Test Your Knowledge 4
|
References
[edit | edit source]Anderson, C.A., & Bushman, B.J. (2002). Human aggression. Annual Review of Psychology, 53, 27-52.
Archer, J. (1991). The influence of testosterone on human aggression. British Journal of Psychology, 82, 1-28.
Archer, J., Birring, S.S., & Wu, F.C.W. (1998). The association between testosterone and aggression among young men. Aggressive Behaviour, 24, 411-420.
Archer, J., & Lloyd, B. (1985). Sex and gender. New York: Cambridge University Press.
Bandura, A. (1977). Social learning theory. Englewood Cliffs, NJ: Prentice-Hall.
Baron, R.A., & Richardson, D.R. (1994). Human Aggression. New York: Plenum.
Berkowitz, L. (1989). Frustration-aggression hypothesis: Examination and reformulation. Psychological Bulletin, 106, 59-73.
Berkowitz, L. (1993). Pain and aggression: Some findings and implications. Journal of Motivation and Emotion, 17, 277-293.
Bolger,N., DeLongis, A., Kessler,R. C., & Wethington, E. (1989). The contagion of stress across multiple roles. Journal of Marriage and the Family, 51, 175-183.
Campion, M.A., Medsker, G.J., & Higgs, A.C. (1993). Relations between work group characteristics and effectiveness: Implications for designing effective work groups. Personnel Psychology, 46, 823-850.
Capozzoli, T., & McVey, R. (1996). Managing Violence in the Workplace. St. Lucie Press. Delray Beach: Florida.
Carlson, N.R. (1999). Foundations of physiological psychology (4th ed.). New York: Allyn & Bacon.
Cleare, A., & Bond, A. (1997). Does central oserotonergic function correlate inversely with aggression? A study using d-fenfluramine in healthy subjects. Psychiatry Research, 69, 89-95.
Chappell, D., & Di Martino, V. (1998). Violence at Work. International Labour Office, Geneva.
Cherry, D., & Upston, B. (1997). Managing Violence and Potentially Violent Situations: A Guide for Workers and Organisations. Centre for Social Health, Heidelberg West, Victoria.
Cortina, L. M., V. J. Magley, J. H. Williams, & R. D. Langhout (2001). Incivility in the Workplace: Incidence and Impact. Journal of Occupational Health Psychology, 6, 64-80.
Dale, R. Tobin, W., & Wilson, B. (1997). Workplace Violence: Another Dimension of Precarious Employment. Just Policy, 10, 3–12.
Dollard, J., Doob, L., Miller, N.E., Mowrer, O., & Sears, R. (1939). Frustration and aggression. New Haven, CT: Yale University Press.
Egger, M.D., & Flynn, J.P. (1963). Effect of electrical stimulation of the amygdala on hypthalamically elicited attack behaviour in cats. Journal of Neurophysiology, 26, 705-720.
Gates, E. (1995). Sage systems of work: Managing to avoid violence; dispelling fear. Health and Safety at Work, 17, 40–42.
Gaymer, J. (1999). Assault Course. Occupational Health, 51, 12–13.
Gianakos, I. (2002). Issues of anger in the workplace: Do gender and gender role matter? The Career Development Quarterly, 51, 155-175.
Hambrick, D.C., & Mason, P.A. (1984). Upper echelons: The organization as a reflection of its top managers. Academy of Management Review, 193-206.
Hartup, W.W. (1998). Cooperation, close relationships, and cognitive development. In W.M. Bukowski, A.F. Newcomb, & W.W. Hartup (Eds.), The company they keep: Friendship in childhood and adolescence. Cambridge studies in social and emotional development (pp. 213-237). New York: Cambridge University Press.
Heskett, S. (1996). Workplace Violence: Before, During and After. Butterworth-Heinemann. Boston.
Higley, J., Mehlman, P., Taub, D., Higley, S., Suomi, S., Linnoila, M., & Vickers, J.H. (1992). Cerebrospinal fluid monoamine and adrenal correlates of aggression in free-ranging rhesus monkeys. Archives of General Psychiatry, 49, 436-441.
Huesmann, L.R. (1986). Psychological processes promoting the relation between exposure to media violence and aggressive behaviour by the viewer. Journal of Sociological Issues, 42, 125-140.
King, H.E. (1961). Psychological effects of excitation in the limbic system. In D.E. Sheer (Ed.), Electrical stimulation of the brain. Austin: University of Texas Press.
LeBlanc, M.M., & Kelloway, E.K. (2002). Predictors and outcomes of workplace violence and aggression. Journal of Applied Psychology, 87, 444-453.
Lore, R., & Schultz, L.A. (1993). Control of human aggression: A comparative perspective. American Psychologist, 48, 16-25.
Mayhew, C. 2000. Preventing violence within organisations: A practical Handbook. Australian Institute of Criminology, 29, 1-47.
Mischel, W. (1973). Toward a cognitive social learning reconceptualization of personality. Psychological Review, 39,351-364.
Morrison, R.L. (2008) Negative relationships within the workplace: Associations with organisational commitment, cohesion, job satisfaction and intention to turnover. Journal of Management & Organisation, 14, 330 – 344.
Mowday, R.T., Steers, R.M., & Porter, L.W. (1979). The measurement of organisational commitment. Journal of Vocational Behaviour, 14, 224-227.
Mullen, E. (1997). Workplace violence: Cause for concern or the construction of a new category of fear? Journal of Industrial Relations, 9, 22–32.
Myers, D. (1996). A workplace violence prevention planning model. Journal of Security Administration, 19, 1–19.
Olweus, D. (1988). Environmental and biological factors in the development of aggressive behaviour. In W. Buikhuisen, & S.S. Mednick (Eds.), Explaining criminal behaviour: Interdisciplinary approaches (pp. 90-120). Leiden, Netherlands: E.J. Brill.
Randall, P. (1997). Adult Bullying: Perpetrators and Victims, Routledge, London.
Reynolds, P. (1994). Dealing with crime and aggression at work: A handbook for organizational action. McGraw-Hill, London.
Robinson, B.W., Alexander, M., & Browne, G. (1969). Dominance reversal resulting from aggressive responses evoked by brain telestimulation. Physiology and Behaviour, 4, 749-752.
Simmons, R. (2002). Odd girl out. New York: Harcourt.
Speer, R. (1997), Workplace violence: Moving beyond the headlines. Women Lawyers Journal, 83, 6–12.
Suomi, S.J. (2000). A biobehavioural perspective on developmental psychopathology: Excessive aggression and seretonergic dysfunction in monkeys. In A.J. Sameroff, & M. Lewis (Eds.), Handbook of developmental psychopathology (pp. 237-256). New York: Kluwer Academic/Plenum Publishers.
Strachan, G., French, E., & Burgess, J. (2010). Managing diversity in Australia. Sydney: Mcgraw Hill.
Van Fleet, D.D. & Van Fleet, E.W. (2007). Preventing workplace violence: the violence volcano metaphor. Journal of applied Management and Entrepreneurship, 12, 17-30.
Whiting, J. W.M., & Child, I.L. (1953). Child training and personality: A cross cultural study. New Haven, CT: Yale University Press.
Witkowski, M.J. (1995). Workplace violence: Problems and prevention suggested by Cal/OSHA workplace security guidelines. Security Journal, 6, 213–18.
Wynne, R., Clarkin, N., Cox, T., & Griffiths, A. (1997). Guidance on the prevention of violence at work. European Commission, Brussels.