Few management challenges are as draining as dealing with a team member whose behaviour is consistently negative, disruptive, or harmful to others. The word toxic gets used loosely, but the reality is serious: one person's persistent negativity, undermining, or aggression can erode trust, destroy morale, and drive your best people away. The longer it goes unaddressed, the more damage it causes, not just to the team but to your credibility as a leader. People watch how you handle difficult behaviour, and inaction sends a powerful message.
Tolerating toxic behaviour to avoid a difficult conversation is not kindness. It is a choice to protect one person at the expense of everyone else.
Recognising toxic behaviour
Toxic behaviour is not always obvious. For more on this, see our guide on having difficult conversations. It is rarely someone shouting in a meeting, though that happens too. More often it is subtle: consistent negativity that drains energy, quiet undermining of colleagues, taking credit for others' work, spreading gossip, or creating an atmosphere where people feel unsafe to speak up. The challenge is distinguishing between someone having a bad week and someone whose behaviour represents a pattern.
The clearest signal is the effect on others. The catchupsin Manager Toolkit supports this. If multiple people are changing their behaviour to accommodate or avoid one individual, that is a pattern worth investigating. If new starters are warned about someone before they even join, the problem is well established. Trust the team's experience, even when the person in question is otherwise competent.
Impact on team dynamics
With toxic behaviour
People hold back ideas
Energy drains in meetings
Best people start leaving
After addressing it
People contribute openly
Meetings feel safe
Trust rebuilds over time
One person's behaviour shapes the experience of everyone else.
- Consistent negativityOccasional frustration is human. But when someone is reliably the voice of cynicism, dismissal, or complaint in every discussion, it becomes corrosive. Pay attention to the energy in the room when they speak versus when they are absent.
- Undermining othersThis can look like publicly questioning a colleague's competence, subtly discrediting someone's ideas, or going around people rather than through them. It often happens just out of sight, which makes it harder to address.
- Resistance to feedbackEveryone finds feedback uncomfortable at times. But a toxic team member consistently deflects, denies, or retaliates when given constructive input. They may frame themselves as the victim, shifting blame rather than reflecting.
- Creating factionsThey build alliances by bonding over shared complaints rather than shared goals. This creates an us-versus-them dynamic within the team that fragments trust and makes collaboration more difficult for everyone.
- Emotional volatilityUnpredictable reactions make others walk on eggshells. When people cannot predict how someone will respond, they stop sharing ideas, raising concerns, or being honest. The team becomes smaller even though the headcount has not changed.
Having the conversation
Addressing toxic behaviour requires directness, preparation, and composure. This is not a casual chat. Our article on handling underperformance explores this further. It is a structured conversation where you name specific behaviours, explain their impact, and set clear expectations for change. Many managers avoid this conversation because they fear conflict, but avoidance makes the situation worse and signals to the rest of the team that the behaviour is acceptable.
Go into the conversation with documented examples. Vague feedback like "your attitude needs to change" is easy to dismiss. Specific observations like "in the planning meeting on Tuesday, you interrupted Sarah three times and dismissed her proposal without engaging with it" are much harder to deny and much easier to act on.
Feedback that works
Specific, documented observations are far harder to dismiss.
- Prepare with evidenceDocument specific incidents with dates, what happened, and who was affected. Patterns are more compelling than isolated examples. Keep your records factual and free from emotional language.
- Focus on behaviourAddress what they do, not who they are. "You have interrupted colleagues in three consecutive meetings" is actionable. "You are a difficult person" is a character judgement that invites defensiveness.
- State the impactExplain clearly how their behaviour affects others and the team. They may genuinely not realise the effect they are having. Connecting their actions to consequences makes the feedback concrete and harder to rationalise away.
- Set expectationsBe explicit about what needs to change and by when. "I need to see you engaging respectfully in team discussions starting from our next meeting" is a clear, measurable expectation. Avoid vague requests like "be more positive."
Setting boundaries
After the initial conversation, the real work begins. You need to hold the line on the expectations you set while giving the person a genuine opportunity to change. This requires consistent follow-up and a willingness to have repeated conversations if progress stalls. Change does not happen overnight, but you should see evidence of effort within a reasonable timeframe.
Be clear about consequences. If the behaviour does not improve, what happens next? This is not about threatening someone. It is about being transparent about the path they are on and what the organisation expects. People deserve to know where they stand, even when the message is uncomfortable.
- Follow up regularlySchedule check-ins specifically to discuss behaviour, not just performance. These conversations should be frequent enough to maintain momentum but not so frequent that they feel punitive. Fortnightly is often a good rhythm.
- Document everythingKeep a written record of every conversation, the expectations set, and the progress observed. This protects you, the individual, and the organisation. If things escalate, you will need this trail.
- Protect the teamWhile you are working with the individual, continue to check in with the rest of the team. They need to know that you are aware of the situation and taking action. You do not need to share details, but you should acknowledge their experience.
- Recognise improvementIf the person makes genuine effort, name it. Behavioural change is hard, and acknowledging progress reinforces the right direction. People are more likely to sustain change when it is noticed and appreciated.
- Hold the lineIf expectations are not met despite clear communication and support, do not lower the bar. Reducing your expectations to match their behaviour tells the rest of the team that standards are negotiable. Consistency matters enormously here.
When to escalate
Not every situation can be resolved through coaching and conversation alone. There comes a point where the behaviour is either too severe to manage informally, too persistent despite clear feedback, or causing too much damage to justify further patience. Knowing when to escalate is a critical judgement call, and delaying too long is the more common mistake.
Escalation is not failure. It is responsible management. Involving HR, your own manager, or a formal process is sometimes the right path for everyone involved, including the person whose behaviour is the problem. Formal processes exist to ensure fairness, and using them shows that you take the situation seriously.
- Severity thresholdsSome behaviours warrant immediate escalation regardless of prior conversations. Bullying, harassment, discrimination, and threats to safety should go straight to HR. Do not attempt to manage these informally.
- Repeated patternsIf you have had the conversation multiple times, set clear expectations, and the behaviour has not changed, it is time to involve others. Three clear feedback cycles with no improvement is a reasonable threshold.
- Impact on retentionIf good people are leaving or asking to transfer because of one individual, the cost of inaction is too high. Losing your best contributors to protect someone who refuses to change is a poor trade.
- Seek support earlyYou do not have to wait until the situation is critical to speak with HR or your own manager. Getting advice early, even informally, helps you handle the situation better and ensures you are following the right process from the start.
Frequently asked questions
Document conversations that matter
Use structured catchups to track difficult conversations, set expectations, and follow up with consistency.