When Coworkers Become Violent

A new study explores violence in the workplace and how it might be prevented.

Posted Jan 29, 2018

Workplace violence and aggression can take a variety of different forms. 

Aside from the high-profile and often graphic episodes of violence that you might hear about in the news, there are other examples of workplace hostility that are much more common. These episodes can range from verbal harassment to actual physical assaults that can result in injuries or even death. And the consequences of experiencing or witnessing this in the workplace can be devastating. Not only are many employees intimidated by the fear of more violence, but continuing episodes such as these can lead to poor workplace morale, loss of productivity, and even affect the health of workers who are unable to cope.    

While most workplaces have policies in place to protect employees from potentially violent coworkers, this isn't always the case and, with more subtle forms of harassment, may be difficult for some workers to prove. There is also the problem of distinguishing between workplace violence and workplace aggression. As a rule, workplace violence involve either inflicting or attempting to inflict harm on another employee (this can include unwanted sexual contact or verbal threats of violence).  Workplace aggression, on the other hand, usually involves psychological rather than physical harm (i.e., verbal abuse, intimidation, deliberate property damage, or humiliation).  

Available statistics on the prevalence of actual workplace violence usually places it around one to five percent, a figure that seems to hold up for Canada, the United States, and internationally. When looking at workplace aggression, however, the prevalence rate is often hard to determine because most incidents go unreported.  Based on employee surveys on how often workplace aggression occurs, the prevalence rate usually hovers around seven to ten percent. 

But other studies suggest that actual incidence of workplace aggression is much higher. For example, according to the 2014 Public Service Employee Survey which specifically looks at workplace harassment experienced by Canadian public service workers, 19 percent of employees surveyed reported some form of harassment over a two-year period. Of those, only two percent reported experiencing some form of physical violence with most other incidents involving verbal harassment, deliberate humiliation, unwelcome sexual comments or attention, 

Whatever form workplace aggression or violence takes, identifying why it happens is often difficult. When looking at workplace violence specifically, what little research is available usually comes from the forensic literature. Still, these studies identify specific risk factors that increase the likelihood of workers becoming violent. They usually include such problems as substance abuse, antisocial personality traits, prior history of violence (usually including a history of criminal charges), and antisocial attitudes. 

But is it possible to identify potentially violent employees before the violence takes place? A new research study published in the Journal of Threat Assessment and Management takes a closer look at workplace aggression and some of the risk factors that seem to be related to why it happens. Michael C. Seto of the University of Ottawa’s Institute of Mental Health Research led a team of Canadian researchers to examine workers who had been referred by their employer for a mental health and risk assessment following an episode of workplace violence. All of the referred workers received a psychological assessment including tests of personality, violence risk, and psychopathic characteristics.

 Archived clinical records from the  Workplace Violence Assessment Clinic in Toronto, Ontario provided information on 326 employees (94.8 percent of whom were men). Due to the small number of female cases, they were dropped from the study and a final sample of 306 employees were used for the study.  For the 306 workers studied, the average age was around 35 who had worked an average of nine years before the violent incident occurred. None of the incidents involved homicide and only 28.4 percent involved a violent incident (causing or intending to cause physical harm).  All the remaining workers had been referred for one or more episodes of workplace aggression (whose behaviors did not involve actual or intended physical harm).

In comparing violent workers to workers who had been referred for incidents of aggression, there were few real differences except that violent employees were more likely to be either married or in a common-law relationship. As for risk factors that could predict future workplace violence, the main factor identified was having a history of previous violent behaviour. The researchers also compared workers who had been referred to the clinic for a single violent incident (67 percent) to the 33 percent of workers who had engaged in workplace violence on two or more occasions. 

Though there was no difference in terms of length of time at work or average age, repeatedly violent workers showed clear evidence significant problems in their personal lives. This included having a history of childhood physical abuse, substance abuse issues, anger problems, and also meeting the DSM criteria for some form of personality disorder. Repeatedly violent workers also had a history of  making threats of physical violence, previous work suspensions and/or terminations, and were also much more likely to have one or more incidents of being intoxicated at work. Not surprisingly, having anger issues was the single factor most likely to predict repeated workplace violence.

So, what can we make of all this? While workplace violence is much less common than workplace aggression, it is usually treated much more seriously, including having criminal charges being laid in many cases. Overall, both aggressive and violent workers are more likely to target coworkers rather than supervisors or subordinates but there doesn't seem to be much difference between violent and aggressive workers otherwise. There also doesn't seem to be that much difference between workers who engage in workplace violence for the first time and workers with a history of repeat violence.

Still, some of the results of this study were surprising. First of all, marital status doesn't seem to play a role in preventing violence, though many previous studies have suggested the opposite.  It also raises the possibility that workplace violence may be significantly related to domestic violence as well, something that needs to be explored further by researchers. There are also other warning signs that might suggest an increased risk of workplace violence. Workers with a history of childhood physical abuse, problems with drugs or alcohol, prior terminations and/or suspensions, and clear problems controlling anger seem especially likely to act out in a violent or aggressive way and may make them easier to identify in future.  

As Seto and his co-authors acknowledge, there are significant limitations in this research, including the fact that the workers examined in this study aren't really representative of employees in general. Also, the researchers conducting this study didn't follow up the workers after they left the clinic so they were unable to make any long-term conclusions about whether these workers continued their problem behavior over time. 

Still, these findings can be useful in creating workplace health and safety programs that might make risk management easier for both employers and employees. Given how serious workplace violence can be, finding better solutions is essential for making workplaces safer.


Geck, Celia M.,Grimbos, Teresa,Siu, Maurice,Klassen, Philip E.,Seto, Michael C.  Violence at work: An examination of aggressive, violent, and repeatedly violent employees.  Journal of Threat Assessment and Management, Vol 4(4), Dec 2017, 210-229

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