Toxic employees in the workplace present a unique threat to businesses. Their behaviour pervades team dynamics, undermines the authority of managers, the efficiency of business operations and the wellbeing of fellow employees.
Identifying Common Types of Toxic Behaviour
Three common types of toxic behaviour include:
- The Complainer: This employee looks to find fault in almost every situation, spreads their negative energy amongst the team and dampens team morale.
- The Narcissist: This employee has an inflated sense of self-importance, they are overconfident, lack empathy and never take accountability or responsibility often deflecting from their own underperformance by pointing out other people’s mistakes.
- The Aggravator: This type of employee belittles, humiliates and insults others. They have a tendency to spread misinformation, gaslight and manipulate others. They may exclude people from meetings and projects under the guise of professionalism and their behaviour is often targeted towards a specific or small number of individuals.
The Consequences of Inaction
When managers fail to address such conduct swiftly and visibly, they risk appearing ineffective or inconsistent, further encouraging disruptive behaviour and disempowering those in leadership roles.
The Cultural Impact of Toxicity
Toxic behaviour is also a cultural contaminant as it spreads silently through gossip, cliques, and negativity, derailing strategic priorities. Collaboration between individuals and teams suffers over time, high-performing employees may disengage or exit altogether, leaving a vacuum filled with underperformance.
Preserving Trust and Confidence
In every employment relationship, there is an implied duty of ‘mutual trust and confidence.’ When there is a lack of early management intervention to tackle disruptive behaviour, employees may feel frustration and resentment resulting in disengagement or even resignation (which may itself, give rise to a claim of constructive dismissal).
Health, Wellbeing, and Legal Risks
A failure to tackle toxic behaviour could also amount to co-workers suffering heightened stress and anxiety leading to persistent or long-term sickness absences which could amount to a breach of the duty to provide a safe working environment.
As uncomfortable as it might be, employers must act swiftly to tackle disruptive behaviour remembering to follow the ACAS code of practice, acting consistently and proportionately in each case.
Considering Mental Health and Reasonable Adjustments
Where a mental health condition or disability may be a factor in the employee’s behaviour, reasonable adjustments must be considered. However, persistent inappropriate behaviour may justify formal warnings or dismissal if it undermined organisational harmony.
Why Early Intervention Matters
Toxic behaviour erodes more than morale – it compromises authority, productivity and the retention of valuable employees. Early management of such behaviour is essential to maintain a happy and productive workforce.
This article was published in the July/August 2025 edition of London Business Matters.
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