4 Toxic Behaviors That Poison a Team

Early in my HR career at a home nursing agency, I worked with an employee who consistently performed at a high level. They were a staffing coordinator who always found the best matches for nurses and families, and we never had to worry about coverage gaps.

As great as they were, it was like working with a dark cloud in the room. They openly criticized their coworkers and undermined management in front of others. Seeing that unfold before leadership made me think there was nothing I could do.

Fortunately, a corporate HR manager also witnessed the behavior and assured me that it was unacceptable. Then they helped me understand that certain behavior can’t be overlooked, regardless of the employee’s performance metrics.

Behaviors that create a toxic work environment

The most difficult part about toxic behavior is that it doesn’t always violate company policy. The first step is recognizing the patterns and how they impact the broader organization.

Performance as a get-out-of-jail card

Some employees learn early that quality results can buy them leeway. Eventually, their performance is used to justify behavior that may not be accepted elsewhere.

You’ll notice this in how they respond to feedback. They tend to dismiss or minimize constructive feedback and redirect the conversation back to their output. It also shows up in how they work with others. Collaboration may seem optional, and they’ll withhold information or ignore their coworkers’ input unless it aligns with their approach.

Yes, work is getting done, but the team isn’t operating as a cohesive unit.

Charm as a selective weapon

Some employees know exactly how to get ahead, no matter the cost. They may be polished and professional in front of senior leadership, but disrespectful and dismissive to their peers. I’ve also seen this in reverse—some folks are nice to their work buddies and rude to everyone else. 

The point is that they’re selective about who they treat well, which signals that they’re capable of better conduct and intentional in their actions. Each dig chips away at the team’s psychological safety and mutual trust.

Hostility as a default setting

We all know what it’s like to have a bad day, but the majority of us also know that we can’t take it out on others. Hostile employees, on the other hand, respond to everyone with short, dismissive replies and condescending comments.

Unfortunately, when this happens often enough, folks start walking on eggshells just to keep the peace. They think twice before offering feedback and hold back good ideas out of fear of reproach. Over time, avoiding friction takes priority over collaboration and innovation.

Normalizing disrespect: The worst thing leadership can do

Even though the behavior starts with the employee, it doesn’t end there. Leadership plays a role in what happens next. Every time bad behavior is overlooked or explained away, it’s tacitly accepted.

Employees see what gets addressed and what doesn’t. They notice who gets called out and who gets a pass. After a while, this disrespect becomes normalized, and it looks like the one behaving badly is above the rules. This can lead others to test the boundaries or not take leadership seriously.

How to deal with bad behavior

Since toxic behavior lives in a policy gray area, it tends to linger longer than it should. Addressing it is uncomfortable, but it must be done to balance team dynamics and performance.

1. Address it in the moment

Handle the behavior when it happens, or as soon as you reasonably can. A quick, direct conversation is often enough to reset expectations. If the situation calls for more depth, follow up shortly after with a private conversation while it’s still fresh. When you respond in real time, you make the standard clear and prevent the behavior from gaining traction.

2. Be specific about the impact

General feedback like “be more professional” or “work better with the team” is easy to dismiss because it’s vague. Instead, connect the behavior directly to its impact. For example:

• “When you cut people off in meetings, it discourages them from sharing their ideas.”
• “When you challenge decisions in that way, it puts your manager in a difficult position in front of the team.”

This makes the conversation real and shifts it from an opinion to an observable outcome. It also reduces the likelihood of a back-and-forth debate. 

3. Don’t rely on one conversation to fix it

For more serious behaviors, treat the first conversation as the starting point. After you address it, set a clear expectation that you’ll be revisiting it. It can be as simple as saying, “We’ll check back in on over the next couple of weeks.” Then actually follow through with it.

Pay attention to how things show up from day to day. To be more effective, keep your feedback tied to patterns rather than isolated moments. This makes it easier to track whether they’re actually changing over time.

4. Document everything

Make note of all conversations, follow-ups, informal check-ins, verbal warnings, and formal write-ups. Keep things simple and consistent by capturing:

• What happened
• When it happened
• What was said or done to address it
• What is the expectation moving forward

You don’t have to write an essay. Clear, factual notes are perfect. 

If you ever decide to terminate the employee, you’ll have a paper trail that shows exactly what happened. You can reference prior conversations and point to evidence that their behavior hasn’t improved.

When to terminate

At some point, you have to be honest about whether coaching is working. If the behavior hasn’t changed after being addressed, it’s time to consider termination. The longer this behavior continues, the more it affects your team. And it’s the rest of the team that you have to consider in these moments.

Letting go of someone—especially a high performer—is tough, but allowing a toxic environment to thrive is a non-starter.