Monster Employees: 7 Traits, Causes & Workplace Fixes

Understanding toxic employee personality traits is one of the most important steps any manager or HR professional can take to protect workplace culture and productivity. These disruptive behaviors — from chronic absenteeism to outright theft — rarely appear out of nowhere. Research suggests they are often rooted in deeply embedded personality patterns, some of which can be traced back to childhood behavioral tendencies. This article breaks down the specific behaviors that define a toxic or “problem” employee, explores what drives those behaviors psychologically, and offers clear, actionable guidance for employers and coworkers alike.

A landmark long-term study conducted by a New Zealand research team tracked nearly 1,000 individuals from childhood through adulthood and published its findings in a paper titled “Predicting the counterproductive employee in a child-to-adult prospective study.” Their conclusion? Certain early behavioral traits — impulsivity, low conscientiousness, and poor emotional regulation — were significant predictors of counterproductive workplace behavior in adulthood. But it doesn’t stop at individual personality. The workplace environment itself, including management style and job stress levels, can amplify or suppress these tendencies. In short, difficult employee behavior is a complex interaction between who a person is and where they work.

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What Are Toxic Employee Personality Traits? Defining the Problem

A “toxic employee” is any worker whose habitual behavior disrupts workplace order, undermines team morale, and causes measurable harm to colleagues or the organization. This is not about someone having a bad day or making an honest mistake. Rather, it refers to a recurring, patterned set of behaviors that consistently violate professional norms. Research on workplace misconduct causes consistently points to a cluster of personality characteristics that tend to appear together in problem employees.

Key toxic employee personality traits tend to include:

• Low conscientiousness — a tendency to ignore rules, deadlines, and responsibilities without apparent guilt or concern.
• High impulsivity — acting on immediate urges rather than thinking through consequences, which often leads to angry outbursts or reckless decisions.
• Low empathy — difficulty understanding or caring about how one’s actions affect coworkers.
• Entitlement thinking — a belief that normal rules don’t apply to them personally.
• Poor emotional regulation — being easily triggered and unable to calm down without escalating a situation.

It is important to note that these traits exist on a spectrum. Not every difficult employee displays all of them, and environmental factors — such as poor management, excessive stress, or organizational injustice — can cause even well-adjusted employees to temporarily exhibit some of these behaviors. The distinction lies in frequency, severity, and whether the behavior is a stable pattern rather than an isolated reaction.

10 Specific Behaviors That Signal Toxic Employee Personality Traits at Work

Toxic workplace behavior rarely announces itself dramatically on day one — it tends to accumulate through a series of specific, observable actions that individually seem minor but collectively create serious damage. Below are the 10 most commonly documented disruptive coworker traits, each examined in psychological and practical terms.

1. Chronic Lateness and Unexcused Absences

Repeatedly arriving late or calling in absent without advance notice is one of the earliest warning signs of difficult employee behavior. Beyond the immediate disruption to workflow, chronic absenteeism signals a disregard for the collective and an overemphasis on personal convenience. Studies indicate that when this behavior goes unaddressed, it tends to spread: other employees notice, feel the unfairness, and may begin to relax their own standards. Effective responses include:

• Accurately documenting every instance of lateness or absence with timestamps.
• Conducting a private one-on-one meeting to understand whether there is an underlying personal or health issue driving the pattern.
• Creating a clear written improvement plan with follow-up checkpoints.
• Applying consistent disciplinary measures in line with company policy if the behavior persists.

Early, consistent intervention tends to be far more effective than waiting until the pattern becomes entrenched.

2. Faking Illness or Exaggerating Injury

A subtler but equally damaging form of workplace toxic behavior involves feigning or embellishing illness to secure unearned leave. This may range from mild exaggeration of symptoms to more serious misconduct such as submitting falsified medical documentation. Beyond the direct cost to the organization, this behavior erodes trust — both between the employee and management, and among the broader team. When colleagues suspect someone is gaming the sick-leave system, resentment and disengagement tend to follow. Practical countermeasures include:

• Maintaining precise records of all sick-leave instances and patterns.
• Requiring medical documentation for absences exceeding a defined threshold (e.g., 3 consecutive days).
• Investigating suspected abuse while respecting employee privacy and applicable labor laws.
• Investing in genuine employee wellness programs to reduce the actual need for sick leave.

3. Unauthorized Personal Use of Company Property

Taking office supplies home, using company equipment for personal projects, or excessively printing or copying for non-work purposes may seem like minor infractions. However, research on workplace misconduct causes suggests these small violations often indicate a broader attitude of disregard for boundaries and organizational property. An employee who rationalizes taking a box of pens home is more likely to rationalize other boundary violations later. Recommended preventive measures:

• Implementing a clear, written policy on acceptable use of company resources.
• Conducting periodic inventory audits so that discrepancies become visible.
• Establishing explicit consequences for unauthorized personal use.
• Reinforcing a compliance culture through regular team-level conversations, not just top-down mandates.

4. Repeated Conflicts and Confrontations With Supervisors

One of the most disruptive toxic employee personality traits is a persistent pattern of insubordination and confrontation directed at managers. This goes well beyond healthy disagreement or constructive feedback. Problem employee management becomes especially difficult when an individual refuses to follow reasonable instructions, publicly challenges authority, or verbally attacks supervisors in front of peers. This behavior damages the entire team’s sense of safety and cohesion. When investigating these incidents, organizations should:

• Document each incident as objectively as possible, focusing on specific words and actions rather than interpretations.
• Hear both sides before drawing conclusions — occasionally the supervisor’s style may be contributing to the friction.
• Identify the root issue (personality clash, unresolved grievance, poor role fit) and address it directly.
• Apply progressive discipline if the behavior continues after documented counseling.

5. Workplace Violence and Severe Verbal Aggression

Physical aggression or sustained verbal attacks in the workplace represent the most extreme end of difficult employee behavior. An employee who shouts, threatens, or engages in physical altercations demonstrates a severe breakdown in emotional regulation and impulse control — both core components of toxic employee personality traits. This level of behavior creates fear, reduces psychological safety across the whole team, and carries significant legal liability for the organization. Zero tolerance requires:

• A clearly written policy that explicitly prohibits any form of physical or severe verbal aggression, with consequences including immediate suspension pending investigation.
• A safe, accessible reporting mechanism for witnesses and victims.
• Mandatory conflict resolution or anger management support for affected employees.
• In serious cases, involvement of legal counsel or law enforcement may be appropriate.

6. Engaging in High-Risk Behaviors That Threaten Employment

Some toxic employees engage in behaviors so seriously out of bounds that they risk immediate termination — leaking confidential company information, concealing critical errors, or participating in illegal activities that intersect with their role. Research suggests that these high-stakes misconduct patterns tend to correlate with low moral disengagement, where the individual progressively distances themselves psychologically from the ethical implications of their actions. Prevention requires:

• Regular and meaningful compliance training that goes beyond box-checking.
• A whistleblower-safe reporting culture that surfaces problems before they become crises.
• Clear, consistently enforced consequences with no ambiguity about severity.
• Legal consultation when the behavior may have crossed into criminal territory.

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7. Stealing Money From the Workplace

Financial theft by an employee — whether from the company’s cash reserves, a colleague’s wallet, or through expense fraud — is both a serious crime and one of the most trust-destroying forms of workplace toxic behavior. Beyond the immediate monetary loss, the discovery of theft shatters the social contract that makes collaborative work possible. Teams that have experienced internal theft report lasting drops in psychological safety and interpersonal trust, even after the perpetrator is removed. Protective measures include:

• Implementing segregation of duties in financial processes so no single person has unchecked access.
• Installing security cameras in areas where cash handling occurs, with transparent policies on surveillance.
• Conducting regular, unannounced financial audits.
• Reporting criminal conduct to law enforcement — internal discipline alone is insufficient for theft.

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8. Falsifying Time Records

Manipulating time-tracking systems — clocking in early, clocking out late on paper, having a colleague punch in on your behalf, or altering digital records — represents both a financial fraud and a compliance failure. Employees who engage in timesheet fraud tend to view rules as negotiable when personal gain is involved, a mindset that typically extends into other areas of their work. Organizations can reduce this risk through:

• Formalizing explicit rules around time recording in the employee handbook, with clear sanctions for violations.
• Upgrading to biometric or secure digital time-tracking systems that are significantly harder to manipulate.
• Running periodic cross-audits comparing logged hours with output metrics and access logs.
• Treating discovered violations as serious disciplinary matters, not administrative oversights.

9. Stealing Physical Property or Company Assets

Taking physical items from the workplace — office supplies, equipment, inventory, or proprietary materials — is a form of theft that many employees tend to minimize (“it’s just a pen”). However, research on employee integrity consistently shows that the rationalization used for small thefts tends to scale over time. An employee who sees no problem taking stationary home may gradually move toward more significant asset misappropriation. Effective organizational responses include:

• Maintaining a current, accurate asset register and conducting scheduled inventory checks.
• Establishing explicit policies about what employees may and may not take home.
• Treating confirmed theft as a disciplinary matter with appropriate escalation, regardless of the item’s perceived value.
• Creating a culture where integrity is discussed openly and positive behavior is recognized.

10. Deliberately Damaging Equipment or Facilities

Intentional destruction of company property — smashing equipment, defacing walls, or purposely misusing facilities — represents one of the most overt expressions of organizational hostility. Psychologically, this behavior often indicates profound disengagement and resentment toward the employer. It may signal that the employee feels unheard, treated unjustly, or fundamentally disconnected from any sense of organizational belonging. While the behavior itself requires firm disciplinary action, the underlying drivers also deserve investigation. Recommended responses:

• Document the incident thoroughly with photographic evidence and witness accounts.
• Investigate any underlying grievances that may have contributed to the escalation.
• Apply proportionate consequences that match the severity of the damage, up to and including termination.
• Seek financial restitution for damages through appropriate legal channels where warranted.

The Root Causes Behind Difficult Employee Behavior

Understanding why these behaviors emerge is just as important as knowing how to respond to them — because prevention is always more effective than reaction. The New Zealand longitudinal study mentioned earlier found that children who displayed traits such as impulsivity, low self-control, and poor social-emotional skills were significantly more likely to become counterproductive employees decades later. This suggests that some difficult employee behavior has deep dispositional roots. However, this does not mean that behavior is fixed or inevitable.

Research in occupational psychology consistently identifies at least 3 major environmental contributors that can amplify underlying toxic employee personality traits:

• Poor management practices — authoritarian, inconsistent, or dismissive leadership styles can provoke reactive behavior even in relatively well-adjusted employees, and dramatically worsen the behavior of those already prone to misconduct.
• Excessive or unmanaged job stress — when workloads are unsustainable and support systems are absent, employees with low frustration tolerance are particularly vulnerable to behavioral breakdown.
• Perceived organizational injustice — feeling that effort goes unrewarded, that rules are applied unfairly, or that the organization does not care about employees tends to corrode motivation and erode moral constraints on misconduct.

This means that approximately half of the solution to problem employee management lies not in disciplining the individual, but in auditing and improving the conditions that may be feeding the behavior. A psychologically safe, fairly managed, well-supported workplace is simply less likely to produce or amplify the disruptive behaviors described in this article.

Actionable Strategies for Employee Conflict Resolution and Prevention

Effective employee conflict resolution requires a structured, evidence-based approach rather than reactive, ad hoc responses that often escalate rather than de-escalate problems. The following strategies are grounded in occupational psychology research and are designed to address both the individual behavior and the systemic conditions that enable it.

Build a Documentation Habit From Day One

One of the most consistent failures in problem employee management is the absence of clear, dated records. Without documentation, disciplinary actions become legally vulnerable and organizationally inconsistent. Managers should record specific behaviors (not interpretations), dates, times, witnesses, and any responses taken. This serves 3 purposes: it creates an objective account that removes personal bias, it signals to the employee that their behavior is being monitored seriously, and it builds the evidentiary basis needed for progressive discipline or, ultimately, termination with cause.

Conduct Structured, Evidence-Based Conversations

When addressing a toxic employee, the conversation itself matters enormously. Research on confrontation effectiveness suggests that focusing on observable behaviors rather than character judgments significantly reduces defensive reactions. Instead of “You have a bad attitude,” say “On these 3 occasions, you raised your voice at a colleague in a team meeting.” Bring documentation, have a third party present (such as an HR representative), and define specific, measurable behavioral changes expected going forward. Follow up in writing within 24 hours so there is no ambiguity about what was discussed and what is expected.

Use Progressive Discipline Consistently and Transparently

Progressive discipline — moving from verbal warning to written warning to suspension to termination — works best when it is applied consistently across all employees and communicated transparently in company policy. Inconsistency is one of the fastest ways to destroy perceived organizational fairness, which, as noted above, tends to increase rather than decrease misconduct. Employees who see that the rules apply to everyone equally are significantly more likely to respect those rules themselves.

Invest in Management Training as a Prevention Tool

Because toxic employee personality traits are substantially amplified by poor management, investing in leadership quality is one of the highest-leverage prevention strategies available to any organization. Research suggests that managers trained in psychological safety, active listening, and fair conflict resolution tend to have teams with markedly lower rates of counterproductive work behavior. This is not a soft benefit — it has a direct, measurable impact on absenteeism rates, turnover costs, and productivity.

Create Safe, Accessible Channels for Reporting Misconduct

Many incidents of workplace toxic behavior go unreported because witnesses and victims fear retaliation or do not trust the process. Organizations that establish clearly communicated, genuinely confidential reporting mechanisms — whether through HR, an ombudsperson, or an anonymous digital platform — tend to surface problems much earlier, before they escalate. Early detection is almost always associated with cheaper and less damaging resolution.

Frequently Asked Questions

What personality traits are most commonly associated with toxic employees?

Research suggests that toxic employees tend to share several core personality characteristics: low conscientiousness (disregard for rules and responsibilities), high impulsivity (acting without thinking through consequences), low empathy (difficulty understanding how their actions affect others), a sense of entitlement (believing normal rules don’t apply to them), and poor emotional regulation (escalating quickly when challenged). These traits often appear together and tend to remain relatively stable over time, though workplace environment can significantly amplify or suppress them.

How can managers identify a toxic employee early before serious damage occurs?

Early warning signs of difficult employee behavior include a pattern of unexplained absences or chronic lateness, increasing friction with colleagues or supervisors, subtle boundary violations such as misusing company resources, and a noticeable drop in work quality or engagement. The key word is “pattern” — a single incident rarely signals a toxic employee, but repeated behaviors over weeks or months are a strong indicator. Maintaining consistent documentation from early on is the most practical way to distinguish patterns from isolated events.

Can a toxic employee’s behavior be changed through coaching or support?

In some cases, yes — particularly when the behavior is largely driven by situational factors such as poor management, excessive stress, or unresolved grievances. Research indicates that structured coaching, clear behavioral expectations, and a psychologically safer work environment can reduce problem behaviors meaningfully. However, when the behaviors are deeply rooted in stable personality traits such as high psychopathy or narcissism, improvement tends to be limited and slow. A combined approach — addressing both individual behavior and environmental conditions — produces the best outcomes.

What is the difference between a difficult coworker and a genuinely toxic employee?

A difficult coworker may occasionally behave poorly due to stress, communication differences, or situational conflict — but generally responds to feedback and adjusts their behavior over time. A genuinely toxic employee, by contrast, displays a persistent, recurring pattern of disruptive behavior that continues despite feedback, documentation, and consequences. The distinction lies in consistency and responsiveness: difficult employees can usually improve with proper support, while truly toxic employees tend to escalate or shift their behavior to new targets rather than genuinely change.

How does workplace environment contribute to toxic employee behavior?

Workplace environment plays a substantial role in either amplifying or containing toxic employee personality traits. Studies suggest that poor or inconsistent management, perceived organizational injustice, excessive and poorly managed job stress, and the absence of clear behavioral norms all increase the likelihood of counterproductive behavior — even among employees who would otherwise function well. Approximately half of effective problem employee management therefore involves auditing and improving the workplace conditions that feed misconduct, rather than focusing solely on the individual employee.

What are the legal considerations when disciplining or terminating a toxic employee?

Disciplinary and termination actions must be grounded in documented, objective evidence of specific behavioral violations — not general character assessments or subjective impressions. Progressive discipline should be applied consistently across all employees to avoid claims of selective treatment. Termination typically requires demonstrating both a legitimate business reason and that the action was proportionate to the offense. Specific legal requirements vary by jurisdiction and employment contract, so consulting an employment law professional before proceeding with termination is strongly advisable in most cases.

How can organizations protect other employees from the effects of a toxic coworker?

Protecting the broader team requires both proactive and reactive measures. Proactively, organizations should establish confidential reporting channels, conduct regular workplace climate surveys, and invest in management training so that problems are caught early. Reactively, when a toxic employee is identified, swift and consistent action — rather than prolonged tolerance — limits secondary harm to the team. Research indicates that employees who see problem behavior addressed promptly tend to report higher trust in management and stronger organizational commitment, even if they were not directly targeted.

Summary: Recognizing and Responding to Toxic Employee Personality Traits

Toxic employee personality traits — from chronic absenteeism and petty theft to outright aggression and financial fraud — represent a genuine threat to workplace health, team morale, and organizational performance. As this article has outlined, these behaviors are not random: research suggests they tend to be driven by a recognizable cluster of personality characteristics, often amplified by problematic workplace conditions. The good news is that both dimensions are manageable. Organizations that combine consistent documentation, structured performance conversations, fair progressive discipline, strong management, and safe reporting channels are significantly better equipped to prevent, detect, and resolve problem employee situations before they escalate. Understanding the psychology behind disruptive coworker traits is the first and most powerful step — because you cannot effectively change what you haven’t clearly identified. If any of the behaviors described here feel familiar in your own workplace, take time to reflect on which specific patterns you’re observing, and use that clarity to decide on your next, evidence-based step.