The Effects of Individual Differences and Charismatic Leadershipon Workplace AggressionWillie Hepworth and Annette TowlerUniversity of Colorado at DenverThis study examined the effects of individual differences variables (trait anger, self-control,negative affectivity, attitudes toward revenge, and attributional style) and charismatic leadershipon incidents of workplace aggression in a sample of 213 employees from a wide range oforganizations. Hierarchical multiple regression analyses indicated that the individual differencesvariables accounted for 27% of the variance in workplace aggression and that charismaticleadership accounted for an additional 3% after controlling for individual differences. In addition,psychological empowerment partially mediated the relationship between charismatic leadershipand workplace aggression.Twenty years ago the term “going postal” wasrelatively unknown in American vocabulary. Now,the term has become a familiar phrase to describevarious types of violence. For the period between1993 and 1999 in the United States, an average of 1.7million violent victimizations per year were commit-ted against people who were at work or on duty,according to the National Crime Victimization Sur-vey (Bureau of Justice Statistics, 2001). The Bureauof Labor Statistics (2000) Survey of OccupationalInjuries and Illnesses reported a total of 16,664 work-place nonfatal assaults and violent acts with lostworkdays in 1999.Although the impression derived from the increasein media reports over the last several years on theexpanding phenomena of workplace violence isalarming, severe acts of violence involving directphysical assault represent relatively rare events atwork (Neuman & Baron, 1998). However, workplaceaggression is much more prevalent and may proveextremely damaging to individuals and organizations(Neuman & Baron, 1998). Workplace aggression isemployee behavior that is intended to harm current orprevious coworkers or the organization to which theyare presently or have previously been employed(Baron & Neuman, 1999; Martinko & Zellars, 1998).Workplace aggression ranges from subtle and covertactions to active confrontations, the destruction ofproperty, and direct physical assaults (Barling, 1996;Robinson & Bennett, 1995). In this study, our mea-sure of workplace aggression does not include itemsmeasuring assault or physical violence.Given the seriousness of workplace aggression,researchers have attempted to identify situational andindividual factors that influence aggressive behavior.A study by Douglas and Martinko (2001) suggeststhat individual differences play a large role in pre-dicting workplace aggression, accounting for 62% ofthe variance in workplace aggression. Additional re-search also suggests that situational factors play animportant part in predicting workplace aggression(Robinson & O’Leary-Kelly, 1998; Skarlicki &Folger, 1997). For example, workplace situationalfactors, such as modeling of team members’ antiso-cial behaviors, accounted for almost 40% of the vari-ance in workplace aggression (Robinson & O’Leary-Kelly, 1998). In a study examining situationalinfluences on workplace aggression, perceptions ofinjustice in the workplace significantly accounted for68% of the variance in retaliatory behaviors (Skar-licki & Folger, 1997).Previous research suggests that both dispositionaland situational factors are important predictors ofworkplace aggression. However, determining the rel-ative importance of dispositional and situational vari-ables has not been investigated in previous research.These studies tend to focus on either situational orWillie Hepworth and Annette Towler, Department ofPsychology, University of Colorado at Denver.This article is part of Willie Hepworth’s master’s thesisthat was completed at University of Colorado at Denverunder the supervision of Annette Towler. A version of thearticle was presented at the Society of Industrial/Organiza-tional Psychology conference in Orlando, Florida, in April2003.We thank Mitch Handelsman and Donna Chrobot-Masonfor their useful comments on an earlier version of thisarticle.Correspondence concerning this article should be ad-dressed to Annette Towler, Department of Psychology, Uni-versity of Colorado at Denver, Mail Box 173, P.O. Box173364, Denver, CO 80217-3364. E-mail: [email protected] of Occupational Health Psychology2004, Vol. 9, No. 2, 176–185Copyright 2004 by the Educational Publishing Foundation1076-8998/04/$12.00 DOI: 10.1037/1076-8998.9.2.176176dispositional variables without considering the jointeffects of these variables on workplace aggression.Douglas and Martinko’s (2001) study also raised theissue of whether situational variables make an incre-mental contribution after accounting for the effect ofdispositional variables on workplace aggression.Apart from including demographic variables in theirmodels (Robinson & O’Leary-Kelly, 1998; Skarlicki& Folger, 1997), studies focusing on the effects ofsituational variables on workplace aggression did notcontrol for dispositional factors. The issue of therelative contribution of situational or dispositionalvariables on workplace aggression is still open.This study is a replication and extension of Doug-las and Martinko’s (2001) study. In addition to fo-cusing on dispositional factors that influence work-place aggression, we included a situational variable,charismatic leadership, in the model. We were inter-ested in investigating whether charismatic leadershipaccounted for a unique amount of variance in work-place aggression, after accounting for dispositionalfactors. We focused on charismatic leadership fortheoretical and practical reasons. First, previous re-search has focused and demonstrated the positiveimpact of charismatic leadership on individual out-comes. To our knowledge, there is no previous re-search examining the impact of charismatic leader-ship on workplace aggression. Second, from apractical perspective, given that workplace aggres-sion is an important issue for organizations to tackle,identifying remedies to reduce workplace aggressionis a crucial step. Given that charismatic leadershipis associated with a wide range of positive out-comes, we believe that in the presence of a charis-matic leader, subordinates are less likely to behaveaggressively.Effects of Dispositional Factors on WorkplaceAggressionDouglas and Martinko’s (2001) research revealedthat particular dispositional factors are