Workplace Behaviour

By The HR Horizon  |  Leadership & Workplace Culture  |  Employee Relations

Reading time: approximately 8 minutes

There is a particular kind of workplace threat that rarely announces itself. It does not shout in meetings or slam doors. It smiles warmly when you walk in, offers to help with a project, and says all the right things in front of leadership. But behind closed doors — in the corridor conversations, the WhatsApp threads, the subtle manoeuvres at the team level — it quietly dismantles trust, isolates individuals, and corrodes the culture you have worked hard to build.

This is the covertly toxic coworker: the silent saboteur. And of all the people challenges a leader must navigate, this is among the most difficult — precisely because the behaviour is designed to be invisible.

This post is a practical guide for leaders who suspect something is wrong with their team dynamic but cannot quite put their finger on it. We will explore what covert toxicity looks like, how to detect it, how to address it, and how to build a culture resilient enough to prevent it from taking hold in the first place.

The most dangerous toxicity in a workplace is not the kind you can see — it is the kind that hides behind a pleasant face and plausible deniability. Leaders who learn to recognise it early protect their teams from damage that can take years to repair.

What Is Covert Toxicity — and Why Is It So Hard to Identify?

Overt toxicity is relatively easy to identify and act upon. A team member who is openly aggressive, frequently disrespectful, or blatantly insubordinate creates a visible problem that demands a visible response. While these situations are never comfortable, at least the behaviour is undeniable.

Covert toxicity operates entirely differently. The covertly toxic individual is often skilled at impression management — presenting themselves positively to those in authority while behaving very differently with peers. They may be charming, articulate, and well-regarded by leadership, which is precisely what makes the situation so difficult to navigate. When concerns are raised about this person, a leader’s instinct is often to dismiss them: surely someone so helpful and professional cannot really be the problem?

But charm is not character. And the gap between how someone presents upward and how they behave laterally — with colleagues, with junior team members, behind closed doors — is one of the most telling indicators of covert toxicity.

Common Forms of Covert Toxic Behaviour

• Subtle exclusion: leaving certain colleagues out of conversations, decisions, or informal gatherings in ways that are deniable individually but form a clear pattern over time.
• Credit theft: taking ownership of others’ ideas or contributions in meetings and reports, often so smoothly that the original contributor cannot challenge it without appearing petty.
• Passive-aggressive communication: delivering undermining messages through tone, implication, or carefully chosen silence rather than direct criticism.
• Selective information sharing: withholding information that colleagues need to do their jobs effectively, disguised as oversight or busyness.
• Reputational damage: spreading doubt about a colleague’s competence, commitment, or character through carefully worded comments to the right people.
• Gaslighting: causing colleagues to question their own perceptions or memory of events, making it harder for them to articulate the harm being done.
• Strategic alliance-building: cultivating influential relationships while quietly isolating those perceived as threats or competition.

None of these behaviours are easy to prove in isolation. That is by design. The covertly toxic individual has usually developed considerable skill in ensuring that each individual act is deniable. The pattern, however, is not.

Action Tip: When assessing a potential covert toxicity concern, shift your frame from ‘can I prove this single incident?’ to ‘what pattern emerges across time, across people, and across contexts?’ The pattern is the evidence.

How to Spot Hidden Toxicity: The Signals Leaders Must Not Ignore

Because the behaviour itself is designed to evade detection, leaders need to develop their ability to read secondary signals — the ripple effects of covert toxicity on the team around it. The covertly toxic individual may be invisible, but the impact on those affected by them rarely is.

Team-Level Warning Signs

• A previously collaborative team that has become visibly fragmented, with certain members increasingly sidelined from team activity.
• A noticeable drop in one or more individuals’ confidence, engagement, or willingness to contribute in team settings.
• Unusual patterns of absence, stress-related leave, or informal requests to be moved to different projects or teams.
• Increased reliance on informal communication — side conversations and messages — rather than team-wide transparency.
• Colleagues who seem reluctant to speak about a particular team member, or who change their demeanour noticeably when that person enters a room.
• A disparity between public praise for an individual and the private reluctance of colleagues to work closely with them.

Individual Warning Signs

• An employee whose performance or engagement has unexpectedly declined without any clear external cause.
• An employee who has become quieter in team settings but more open in private one-to-one conversations.
• An employee who mentions feeling ‘out of the loop’, overlooked, or unsupported — but struggles to identify a specific incident.
• Hesitation or visible anxiety when asked about team relationships, even when the employee presents as otherwise confident.

Leaders should also pay attention to what does not get said. Employees who are experiencing covert toxicity often do not complain directly — partly because they lack concrete evidence, partly because they fear not being believed, and partly because the covertly toxic individual has frequently already managed the narrative around them. The absence of a formal complaint is not evidence that nothing is wrong.

Your team members may not tell you directly that something is wrong — but they will show you. Changes in energy, patterns of withdrawal, reluctance to collaborate: these are the language of a team under pressure. Learn to read it.

Action Tip: Schedule brief individual check-ins with each team member at least monthly. Keep them conversational and low-pressure. Over time, these conversations build enough trust that team members feel safe raising concerns they might not otherwise voice — and they give you the pattern data you need to act.

Creating the Conditions for Concerns to Surface

One of the most powerful things a leader can do to counter covert toxicity is to create a team environment in which people feel genuinely safe raising concerns. This is what psychologists call psychological safety — the belief that you can speak up, share a worry, or flag a problem without fear of punishment, ridicule, or retaliation.

Psychological safety does not happen by default. In many workplaces — particularly in cultures where hierarchy is strong and conflict is avoided — the default is silence. People learn early that raising concerns about colleagues is risky, that nothing will happen as a result, or worse, that the act of raising a concern will somehow reflect poorly on them. Covertly toxic individuals rely on this silence. It is their greatest enabler.

Building psychological safety requires consistent, deliberate action from leadership. It means modelling openness yourself — acknowledging your own uncertainties, inviting challenge, and demonstrating that feedback is genuinely welcomed. It means responding to concerns in ways that reinforce trust: taking them seriously, investigating fairly, and protecting the person who had the courage to raise them. And it means creating formal channels — regular feedback sessions, anonymous pulse surveys, 360-degree feedback processes — that give people options beyond the direct conversation they may not feel able to have.

Practical Tools for Building Psychological Safety

• Regular individual check-ins where team members feel heard without judgement.
• Anonymous pulse surveys that include questions specifically about team relationships and culture.
• 360-degree feedback processes that capture how team members experience one another, not just how they perform against targets.
• Team norms or a team charter that explicitly names the behaviours the group expects of one another and commits to upholding.
• Clear, accessible reporting channels so that concerns can be raised without requiring a face-to-face conversation.

Action Tip: At your next team meeting, open with this question: ‘What is one thing we could do as a team to make it easier for everyone to speak up when something is not working?’ The conversation itself begins to shift the culture — and the answers will tell you a great deal about where the pressure points are.

Investigating Covert Toxicity: Acting Swiftly, Fairly, and Confidentially

When a concern about covert toxicity is raised — whether formally or informally — the leader’s response in the first 48 hours sets the tone for everything that follows. Moving too slowly signals that the concern is not taken seriously. Moving too quickly, without care for due process, risks unfairness and escalation. The right approach is prompt, thorough, and confidential.

Do not dismiss the concern as a personality clash or assume it will resolve itself. Do not make assurances you cannot keep. And do not signal — even inadvertently — that the act of raising the concern was itself problematic. These responses are common, understandable, and deeply damaging to the trust of the person who had the courage to come forward.

A Framework for Investigating Covert Toxicity

1. Listen fully and without prejudgement: allow the person raising the concern to describe their experience completely before asking questions or offering commentary.
2. Document what is shared: record the specific incidents described, the dates, the people involved, and the impact on the individual and team.
3. Broaden your intelligence: speak to other team members in a way that does not betray the original concern — use open questions about team dynamics and culture to gather additional perspective.
4. Look for the pattern: compile what you have heard across individuals and over time. Covert toxicity shows up in patterns, not in isolated incidents.
5. Assess the evidence fairly: resist the pull of your existing impression of the individual concerned. Charm and professional performance do not preclude harmful behaviour toward colleagues.
6. Act on what the evidence supports: whether that is a direct conversation, formal disciplinary action, or a managed exit, the response must be proportionate and documented.
7. Follow up with those affected: check in with the individuals who raised concerns and those affected by the behaviour. Show that the process has led to an outcome, even if the details must remain confidential.

Acting swiftly is not the same as acting rashly. When covert toxicity is suspected, your job is to investigate with care, document with precision, and respond with the courage your team is counting on you to have.

Action Tip: Keep a factual, dated log of any incidents related to a concern — even informal ones. If a situation escalates to a formal process, this record is invaluable. Encourage affected employees to do the same, noting specific dates, words used, and witnesses present.

Addressing the Covertly Toxic Individual Directly

Once the investigation has established a sufficient pattern of concern, the leader must address it directly with the individual involved. This is perhaps the most uncomfortable conversation in a leader’s repertoire — and one of the most important.

The challenge is that covertly toxic individuals are typically skilled in conversation. They may deny, deflect, reframe, or turn the discussion toward the failings of those who raised the concern. They may express hurt or outrage at being questioned. They may offer explanations that make each individual incident sound entirely reasonable. The leader’s role in this conversation is not to be manipulated by any of these responses, however plausible they sound.

Ground the conversation firmly in observable behaviour and documented impact. Focus not on what the individual intended — which is always unknowable and always deniable — but on what has actually happened to the people around them. Make clear what is expected going forward, and what the consequences will be if the behaviour continues. Document the conversation in writing, share a summary with the individual, and set a clear review point.

Key Principles for This Conversation

• Stay evidence-based: refer only to specific, documented incidents and their observed impact.
• Focus on behaviour, not personality: the conversation is about what the person has done, not who they are.
• Be clear about expectations: name the specific behaviours that must change and by when.
• Be equally clear about consequences: do not leave the individual uncertain about what will happen if the behaviour continues.
• Do not negotiate the facts: if the individual attempts to reframe or challenge the documented evidence, hold your position calmly and firmly.

Action Tip: Bring an HR professional or a second senior leader into this conversation where possible. Having a witness protects both parties, ensures the conversation is handled professionally, and reduces the risk of the individual later misrepresenting what was said.

Protecting Your Team: Prevention as a Leadership Priority

Addressing covert toxicity once it has taken hold is difficult, costly, and disruptive. The stronger long-term strategy is to build a team culture that is genuinely inhospitable to it — where the conditions that allow covert toxicity to thrive simply do not exist.

Covert toxicity flourishes where communication is opaque, where recognition systems can be gamed, where performance is judged only on individual output without regard for how people treat one another, and where leaders are too distant from their teams to notice what is really happening. Each of these conditions is within a leader’s power to change.

Culture-Building Strategies That Reduce Toxicity Risk

• Make team health a measurable priority: include questions about team relationships, psychological safety, and collaboration in your regular engagement surveys. Track the results over time.
• Recognise and reward collaborative behaviour explicitly: make it clear that how people achieve results matters as much as what they achieve. Include peer feedback in performance conversations.
• Maintain close enough contact with your team to notice changes: a leader who is present, accessible, and genuinely curious about team dynamics is far harder to mislead than one who manages from a distance.
• Model the behaviour you expect: demonstrating transparency, fairness, and genuine respect in your own conduct sets the standard that the team mirrors.
• Build diverse, cross-functional relationships within the team: covert toxicity struggles when team members have multiple strong relationships and are not dependent on a single person for information, recognition, or access.
• Act on concerns early: the longer a concern about covert toxicity is left unaddressed, the stronger the pattern becomes and the more embedded the harm. Early, proportionate action sends a message that the culture will not tolerate it.

A healthy team culture is not an accident — it is an architecture. The norms you set, the behaviours you reward, the concerns you act on, and the presence you maintain as a leader all determine whether hidden toxicity can take root. Build deliberately, and it cannot.

Action Tip: Review your current performance framework. Does it capture how your people treat one another, or only what they produce? If peer feedback and behavioural expectations are absent from performance conversations, the culture is being left to chance.

When the Covert Toxicity Does Not Stop: Knowing When to Escalate

Sometimes, despite a direct conversation, clear expectations, and a documented review process, the behaviour continues. The individual may become more sophisticated in concealing it, may shift their target to a different colleague, or may simply wait out what they perceive as temporary scrutiny. In these situations, continued tolerance is not patience — it is abdication.

A leader who has followed due process, documented their actions, given the individual a fair and clear opportunity to change, and seen no genuine improvement has a responsibility to escalate. This may mean a formal disciplinary process, a managed exit, or in the most serious cases, a redundancy where the role and the person are genuinely incompatible with the team’s needs going forward.

These decisions are never easy. The covertly toxic individual may be well-regarded externally, may have allies in the organisation, or may be a strong individual performer. None of these factors should outweigh the sustained harm being done to the people around them. The cost of inaction — in turnover, disengagement, lost talent, and cultural damage — always exceeds the cost of decisive action.

Action Tip: Before escalating to a formal process, ensure your documentation is comprehensive: dates, specific incidents, witnesses, the direct conversation that took place, what was agreed, and evidence of continued behaviour post-conversation. A well-documented process is your protection and your foundation for action.

Your Hidden Toxicity Action Checklist: 10 Steps for Leaders

1. Shift your focus from isolated incidents to patterns of behaviour across time and people.
2. Schedule regular one-to-one check-ins to build the trust that allows concerns to surface.
3. Implement anonymous pulse surveys that include questions about team relationships and safety.
4. Use 360-degree feedback to capture how team members experience one another.
5. When a concern is raised, respond promptly, confidentially, and without dismissal.
6. Document all incidents carefully: dates, specific behaviours, impact, and witnesses.
7. Investigate by broadening intelligence across the team — look for the pattern, not just the incident.
8. Address the behaviour directly, grounding the conversation in evidence and impact.
9. Set clear expectations and consequences, and document the conversation in writing.
10. Build a culture of transparency, recognition, and psychological safety so covert toxicity has nowhere to hide.

Final Thoughts

Protecting your team from hidden toxicity is one of the most demanding — and most important — responsibilities of leadership. It requires attentiveness, courage, and a willingness to act on concerns that are sometimes hard to articulate and even harder to prove. It requires you to look beyond the charming surface and ask what is actually happening to the people in your team.

The leaders who do this well do not wait for the damage to become undeniable. They build cultures where honesty is safe, where patterns are noticed, and where the expectation is clear: we treat each other well here, and we hold that standard with the same seriousness we apply to every other measure of performance.

At The HR Horizon, we work with leaders and organisations across the Caribbean and beyond to build the people frameworks, the leadership skills, and the cultural foundations that make workplaces safe, high-performing, and genuinely human. If your team culture is under pressure — visible or hidden — we are here to help.

Ready to build a team culture where everyone is safe to thrive? Explore The HR Horizon’s consulting services and leadership coaching.

About The HR Horizon

The HR Horizon is a Caribbean-based HR consulting and leadership development firm helping SMEs, startups, and emerging leaders build people-first businesses that perform. From executive coaching and HR strategy to practical toolkits and online courses, we equip leaders with the skills, systems, and confidence to manage their people effectively.

Visit us at thehrhorizon.com or contact us at hello@thehrhorizon.com.